Update vendored workhorse to v8.57.0

workhorse/.gitignore

+testdata/data
+testdata/scratch
+testdata/public
+/gitlab-workhorse
+/gitlab-resize-image
+/gitlab-zip-cat
+/gitlab-zip-metadata
+/_build
+coverage.html
+/*.toml

workhorse/.gitlab-ci.yml

+workflow:
+  rules: &workflow_rules
+    # For merge requests, create a pipeline.
+    - if: '$CI_MERGE_REQUEST_IID'
+    # For `master` branch, create a pipeline (this includes on schedules, pushes, merges, etc.).
+    - if: '$CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH'
+    # For tags, create a pipeline.
+    - if: '$CI_COMMIT_TAG'
+    # For stable branches, create a pipeline.
+    - if: '$CI_COMMIT_BRANCH =~ /^[\d-]+-stable$/'
+
+default:
+  image: golang:1.13
+  tags:
+    - gitlab-org
+
+# Disable DIND for SAST because we need to execute a before_script in the gosec-sast job
+variables:
+  SAST_DISABLE_DIND: "true"
+
+verify:
+  script:
+  - make verify
+
+changelog:
+  script:
+  - _support/check_changelog.sh
+  rules:
+  - if: '$CI_MERGE_REQUEST_IID'
+
+.test:
+  services:
+    - name: registry.gitlab.com/gitlab-org/build/cng/gitaly:latest
+      # Disable the hooks so we don't have to stub the GitLab API
+      command: ["/usr/bin/env", "GITALY_TESTING_NO_GIT_HOOKS=1", "/scripts/process-wrapper"]
+      alias: gitaly
+  variables:
+    GITALY_ADDRESS: "tcp://gitaly:8075"
+  script:
+  - go version
+  - apt-get update && apt-get -y install libimage-exiftool-perl
+  - make test
+
+test using go 1.13:
+  extends: .test
+  image: golang:1.13
+
+test using go 1.14:
+  extends: .test
+  image: golang:1.14
+
+test:release:
+  rules:
+    - if: '$CI_COMMIT_TAG'
+  script:
+    - git describe --exact-match
+
+include:
+  - template: Security/SAST.gitlab-ci.yml
+  - template: Security/Dependency-Scanning.gitlab-ci.yml
+  - template: Security/Secret-Detection.gitlab-ci.yml
+
+gosec-sast:
+  before_script:
+    - apk add make
+    - make install
+  rules: *workflow_rules
+
+gemnasium-dependency_scanning:
+  rules: *workflow_rules
+
+secret_detection:
+  rules: *workflow_rules
+
+code_navigation:
+  image: golang:latest
+  allow_failure: true
+  script:
+    - go get github.com/sourcegraph/lsif-go/cmd/lsif-go
+    - lsif-go
+  artifacts:
+    reports:
+      lsif: dump.lsif

workhorse/.gitlab/CODEOWNERS

+* @jacobvosmaer-gitlab @nick.thomas @nolith @patrickbajao

workhorse/CONTRIBUTING.md

+## Contributing
+
+Thank you for your interest in contributing to this GitLab project! We welcome
+all contributions. By participating in this project, you agree to abide by the
+[code of conduct](#code-of-conduct).
+
+## Contributor license agreement
+
+By submitting code as an individual you agree to the [individual contributor
+license agreement][individual-agreement].
+
+By submitting code as an entity you agree to the [corporate contributor license
+agreement][corporate-agreement].
+
+## Code of conduct
+
+As contributors and maintainers of this project, we pledge to respect all people
+who contribute through reporting issues, posting feature requests, updating
+documentation, submitting pull requests or patches, and other activities.
+
+We are committed to making participation in this project a harassment-free
+experience for everyone, regardless of level of experience, gender, gender
+identity and expression, sexual orientation, disability, personal appearance,
+body size, race, ethnicity, age, or religion.
+
+Examples of unacceptable behavior by participants include the use of sexual
+language or imagery, derogatory comments or personal attacks, trolling, public
+or private harassment, insults, or other unprofessional conduct.
+
+Project maintainers have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct. Project maintainers who do not follow the
+Code of Conduct may be removed from the project team.
+
+This code of conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community.
+
+Instances of abusive, harassing, or otherwise unacceptable behavior can be
+reported by emailing contact@gitlab.com.
+
+This Code of Conduct is adapted from the [Contributor Covenant][contributor-covenant], version 1.1.0,
+available at [http://contributor-covenant.org/version/1/1/0/](http://contributor-covenant.org/version/1/1/0/).
+
+[contributor-covenant]: http://contributor-covenant.org
+[individual-agreement]: https://docs.gitlab.com/ee/legal/individual_contributor_license_agreement.html
+[corporate-agreement]: https://docs.gitlab.com/ee/legal/corporate_contributor_license_agreement.html

workhorse/LICENSE

+The MIT License (MIT)
+
+Copyright (c) 2015-2017 GitLab B.V.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

workhorse/Makefile

+PREFIX=/usr/local
+PKG := gitlab.com/gitlab-org/gitlab-workhorse
+BUILD_DIR ?= $(CURDIR)
+TARGET_DIR ?= $(BUILD_DIR)/_build
+TARGET_SETUP := $(TARGET_DIR)/.ok
+BIN_BUILD_DIR := $(TARGET_DIR)/bin
+COVERAGE_DIR := $(TARGET_DIR)/cover
+VERSION_STRING := $(shell git describe)
+ifeq ($(strip $(VERSION_STRING)),)
+VERSION_STRING := v$(shell cat VERSION)
+endif
+BUILD_TIME := $(shell date -u +%Y%m%d.%H%M%S)
+GOBUILD := go build -ldflags "-X main.Version=$(VERSION_STRING) -X main.BuildTime=$(BUILD_TIME)"
+EXE_ALL := gitlab-resize-image gitlab-zip-cat gitlab-zip-metadata gitlab-workhorse
+INSTALL := install
+BUILD_TAGS := tracer_static tracer_static_jaeger continuous_profiler_stackdriver
+
+MINIMUM_SUPPORTED_GO_VERSION := 1.11
+
+export GOBIN := $(TARGET_DIR)/bin
+export PATH := $(GOBIN):$(PATH)
+export GOPROXY ?= https://proxy.golang.org
+export GO111MODULE=on
+
+LOCAL_GO_FILES = $(shell find . -type f -name '*.go' | grep -v -e /_ -e /testdata/ -e '^\./\.')
+
+define message
+	@echo "### $(1)"
+endef
+
+
+.NOTPARALLEL:
+
+.PHONY:	all
+all:	clean-build $(EXE_ALL)
+
+$(TARGET_SETUP):
+	$(call message,"Setting up target directory")
+	rm -rf "$(TARGET_DIR)"
+	mkdir -p "$(TARGET_DIR)"
+	touch "$(TARGET_SETUP)"
+
+gitlab-resize-image: $(TARGET_SETUP) $(shell find cmd/gitlab-resize-image/ -name '*.go')
+	$(call message,Building $@)
+	$(GOBUILD) -tags "$(BUILD_TAGS)" -o $(BUILD_DIR)/$@ $(PKG)/cmd/$@
+
+gitlab-zip-cat:	$(TARGET_SETUP) $(shell find cmd/gitlab-zip-cat/ -name '*.go')
+	$(call message,Building $@)
+	$(GOBUILD) -tags "$(BUILD_TAGS)" -o $(BUILD_DIR)/$@ $(PKG)/cmd/$@
+
+gitlab-zip-metadata:	$(TARGET_SETUP) $(shell find cmd/gitlab-zip-metadata/ -name '*.go')
+	$(call message,Building $@)
+	$(GOBUILD) -tags "$(BUILD_TAGS)" -o $(BUILD_DIR)/$@ $(PKG)/cmd/$@
+
+gitlab-workhorse:	$(TARGET_SETUP) $(shell find . -name '*.go' | grep -v '^\./_')
+	$(call message,Building $@)
+	$(GOBUILD) -tags "$(BUILD_TAGS)" -o $(BUILD_DIR)/$@ $(PKG)
+
+.PHONY:	install
+install:	$(EXE_ALL)
+	$(call message,$@)
+	mkdir -p $(DESTDIR)$(PREFIX)/bin/
+	cd $(BUILD_DIR) && $(INSTALL) $(EXE_ALL) $(DESTDIR)$(PREFIX)/bin/
+
+.PHONY:	test
+test: $(TARGET_SETUP) prepare-tests
+	$(call message,$@)
+	@go test -tags "$(BUILD_TAGS)" ./...
+	@echo SUCCESS
+
+.PHONY:	coverage
+coverage:	$(TARGET_SETUP) prepare-tests
+	$(call message,$@)
+	@go test -tags "$(BUILD_TAGS)" -cover -coverprofile=test.coverage ./...
+	go tool cover -html=test.coverage -o coverage.html
+	rm -f test.coverage
+
+.PHONY:	clean
+clean:	clean-workhorse clean-build
+	$(call message,$@)
+	rm -rf testdata/data testdata/scratch
+
+.PHONY:	clean-workhorse
+clean-workhorse:
+	$(call message,$@)
+	rm -f $(EXE_ALL)
+
+.PHONY: check-version
+check-version:
+	@test -n "$(VERSION)" || (echo "VERSION not set." ; exit 1)
+
+.PHONY:	tag
+tag: check-version
+	$(call message,$@)
+	sh _support/tag.sh "$(VERSION)"
+
+.PHONY:	signed_tag
+signed_tag: check-version
+	$(call message,$@)
+	TAG_OPTS=-s sh _support/tag.sh "$(VERSION)"
+
+.PHONY:	clean-build
+clean-build:
+	$(call message,$@)
+	rm -rf $(TARGET_DIR)
+
+.PHONY:	prepare-tests
+prepare-tests:	testdata/data/group/test.git $(EXE_ALL)
+prepare-tests:	testdata/scratch
+
+testdata/data/group/test.git:
+	$(call message,$@)
+	git clone --quiet --bare https://gitlab.com/gitlab-org/gitlab-test.git $@
+
+testdata/scratch:
+	mkdir -p testdata/scratch
+
+.PHONY: verify
+verify: lint vet detect-context detect-assert check-formatting staticcheck deps-check
+
+.PHONY: lint
+lint: $(TARGET_SETUP)
+	$(call message,Verify: $@)
+	go install golang.org/x/lint/golint
+	@_support/lint.sh ./...
+
+.PHONY: vet
+vet: $(TARGET_SETUP) 
+	$(call message,Verify: $@)
+	@go vet ./...
+
+.PHONY: detect-context
+detect-context: $(TARGET_SETUP)
+	$(call message,Verify: $@)
+	_support/detect-context.sh
+
+.PHONY: detect-assert
+detect-assert:
+	$(call message,Verify: $@)
+	_support/detect-assert.sh
+
+.PHONY: check-formatting
+check-formatting: $(TARGET_SETUP) install-goimports
+	$(call message,Verify: $@)
+	@_support/validate-formatting.sh $(LOCAL_GO_FILES)
+
+# Megacheck will tailor some responses given a minimum Go version, so pass that through the CLI
+# Additionally, megacheck will not return failure exit codes unless explicitly told to via the
+# `-simple.exit-non-zero` `-unused.exit-non-zero` and `-staticcheck.exit-non-zero` flags
+.PHONY: staticcheck
+staticcheck: $(TARGET_SETUP)
+	$(call message,Verify: $@)
+	go install honnef.co/go/tools/cmd/staticcheck
+	@ $(GOBIN)/staticcheck -go $(MINIMUM_SUPPORTED_GO_VERSION) ./...
+
+# In addition to fixing imports, goimports also formats your code in the same style as gofmt
+# so it can be used as a replacement.
+.PHONY: fmt
+fmt: $(TARGET_SETUP) install-goimports
+	$(call message,$@)
+	@goimports -w -local $(PKG) -l $(LOCAL_GO_FILES)
+
+.PHONY:	goimports
+install-goimports:	$(TARGET_SETUP)
+	$(call message,$@)
+	go install golang.org/x/tools/cmd/goimports
+
+.PHONY: deps-check
+deps-check:
+	go mod tidy
+	@if git diff --quiet --exit-code -- go.mod go.sum; then \
+		echo "go.mod and go.sum are ok"; \
+	else \
+		echo ""; \
+		echo "go.mod and go.sum are modified, please commit them";\
+		exit 1; \
+	fi;

workhorse/PROCESS.md

+# GitLab-Workhorse development process
+
+## Maintainers
+
+GitLab-Workhorse has the following maintainers:
+
+- Nick Thomas `@nick.thomas`
+- Jacob Vosmaer `@jacobvosmaer-gitlab`
+- Alessio Caiazza `@nolith`
+
+This list is defined at https://about.gitlab.com/team/.
+
+## Changelog
+
+GitLab-Workhorse keeps a changelog which is generated when a new release
+is created. The changelog is generated from entries that are included on each
+merge request. To generate an entry on your branch run:
+`_support/changelog "Change descriptions"`.
+
+After the merge request is created, the ID of the merge request needs to be set
+in the generated file. If you already know the merge request ID, run:
+`_support/changelog -m <ID> "Change descriptions"`.
+
+Any new merge request must contain either a new entry or a justification in the
+merge request description why no changelog entry is needed.
+
+## Merging and reviewing contributions
+
+Contributions must be reviewed by at least one Workhorse maintainer.
+The final merge must be performed by a maintainer.
+
+## Releases
+
+New versions of Workhorse can be released by one of the Workhorse
+maintainers. The release process is:
+
+-   pick a release branch. For x.y.0, use `master`. For all other
+    versions (x.y.1, x.y.2 etc.) , use `x-y-stable`. Also see [below](#versioning)
+-   run `make tag VERSION=x.y.z"` or `make signed_tag VERSION=x.y.z` on the release branch. This will
+    compile the changelog, bump the VERSION file, and make a tag matching it.
+-   push the branch and the tag to gitlab.com
+-   the new version will only be deployed to `gitlab.com` if [`GITLAB_WORKHORSE_VERSION`](https://gitlab.com/gitlab-org/gitlab/-/blob/master/GITLAB_WORKHORSE_VERSION) is updated accordingly;
+    if applicable, please remind the person who originally asked for a new release to make this change
+    (the MR should include a link back to the [version tag](https://gitlab.com/gitlab-org/gitlab-workhorse/-/tags) and a copy of the changelog)
+
+## Security releases
+
+Workhorse is included in the packages we create for GitLab, and each version of
+GitLab specifies the version of Workhorse it uses in the `GITLAB_WORKHORSE_VERSION`
+file, so security fixes in Workhorse are tightly coupled to the [general security release](https://about.gitlab.com/handbook/engineering/workflow/#security-issues)
+workflow, with some elaborations to account for the changes happening across two
+repositories. In particular, the Workhorse maintainer takes responsibility for
+creating new patch versions of Workhorse that can be used in the security
+release.
+
+As security fixes are backported three releases in addition to master, and
+changes need to happen across two repositories, up to eight merge requests, and
+four Workhorse releases, can be required to fix a security issue in Workhorse.
+This is a lot of overhead, so in general, it is better to fix security issues
+without changing Workhorse. Where changes **are** necessary, this section
+documents the necessary steps.
+
+If you're working on a security fix in Workhorse, you need two sets of merge
+requests:
+
+* The fix itself, in the `gitlab-org/security/gitlab-workhorse` repository
+* A merge request to change the version of workhorse included in the GitLab
+  security release, in the `gitlab-org/security/gitlab` repository.
+
+If the Workhorse maintainer isn't also a GitLab maintainer, reviews will need to
+be split across several people. If changes to GitLab **code** are required in
+addition to the change of Workhorse version, they both happen in the same merge
+request.
+
+Start by creating a single merge request targeting `master` in Workhorse. Ensure
+you include a changelog! If code changes are needed in GitLab as well, create a
+GitLab merge request targeting `master` at this point, but don't worry about the
+`GITLAB_WORKHORSE_VERSION` file yet. 
+
+Once the changes have passed review, the Workhorse maintainer will determine the
+new versions of Workhorse that will be needed, and communicate that to the
+author. To do this, examine the `GITLAB_WORKHORSE_VERSION` file on each GitLab
+stable branch; for instance, if the security release consisted of GitLab
+versions `12.10.1`, `12.9.2`, `12.8.3`, and `12.7.4`, we would see the following:
+
+```
+gitlab$ git fetch security master 12-10-stable-ee 12-9-stable-ee 12-8-stable-ee 12-7-stable-ee`
+gitlab$ git show refs/remotes/security/master:GITLAB_WORKHORSE_VERSION
+8.30.1
+gitlab$ git show refs/remotes/security/12-10-stable-ee:GITLAB_WORKHORSE_VERSION
+8.30.1
+gitlab$ git show refs/remotes/security/12-9-stable-ee:GITLAB_WORKHORSE_VERSION
+8.25.2
+gitlab$ git show refs/remotes/security/12-8-stable-ee:GITLAB_WORKHORSE_VERSION
+8.21.2
+gitlab$ git show refs/remotes/security/12-7-stable-ee:GITLAB_WORKHORSE_VERSION
+8.21.2
+```
+
+In this example, there are three distinct Workhorse stable branches to be
+concerned with, plus Workhorse master: `8-30-stable`, `8-25-stable`, and
+`8-21-stable`, and we can predict that we are going to need to create Workhorse
+releases `8.30.2`, `8.25.3`, and `8.21.3`.
+
+The author needs to create a merge request targeting each Workhorse stable
+branch, and verify that the fix works once backported. They also need to create
+(or update, if they already exist) GitLab merge requests, setting the
+`GITLAB_WORKHORSE_VERSION` file to the predicted workhorse version, and assign
+all the MRs back to the appropriate maintainer(s). The pipeline for the GitLab
+MRs will fail until the Workhorse releases have been tagged; you can use the
+`=workhorse_branch_name` syntax in the `GITLAB_WORKHORSE_VERSION` file to verify
+that the MRs interact as expected, if necessary.
+
+Once all involved maintainers are happy with the overall change, the Workhorse
+maintainer will merge each of the Workhorse MRs and generate new Workhorse
+releases from the stable branches. The tags will be present on the `security`
+mirror and `dev.gitlab.org` **only** at this point.
+
+Once the Workhorse tags exist, the GitLab maintainer ensures that all the GitLab
+MRs are green and assigns those MRs on to the release bot.
+
+The release managers merge the GitLab MRs, tag GitLab releases that reference
+the new Workhorse tags, and release them in the usual way.
+
+Once the security release is done, the Workhorse maintainer is responsible for
+syncing the changes to the `gitlab-org/gitlab-workhorse` repository. Push the
+changes to `master`, the new tags, and all the changes to the stable branches.
+
+This process is quite involved, very manual, and extremely error-prone; work is
+ongoing on automating it.
+
+## Versioning
+
+Workhorse uses a variation of SemVer. We don't use "normal" SemVer
+because we have to be able to integrate into GitLab stable branches.
+
+A version has the format MAJOR.MINOR.PATCH.
+
+- Major and minor releases are tagged on the `master` branch
+- If the change is backwards compatible, increment the MINOR counter
+- If the change breaks compatibility, increment MAJOR and set MINOR to `0`
+- Patch release tags must be made on stable branches
+- Only make a patch release when targeting a GitLab stable branch
+
+This means that tags that end in `.0` (e.g. `8.5.0`) must always be on
+the master branch, and tags that end in anthing other than `.0` (e.g.
+`8.5.2`) must always be on a stable branch.
+
+> The reason we do this is that SemVer suggests something like a
+> refactoring constitutes a "patch release", while the GitLab stable
+> branch quality standards do not allow for back-porting refactorings
+> into a stable branch.

workhorse/README.md

+# GitLab Workhorse
+
+GitLab Workhorse is a smart reverse proxy for GitLab. It handles
+"large" HTTP requests such as file downloads, file uploads, Git
+push/pull and Git archive downloads.
+
+Workhorse itself is not a feature, but there are [several features in
+GitLab](doc/architecture/gitlab_features.md) that would not work efficiently without Workhorse.
+
+## Documentation
+
+Workhorse documentation is available in the [`doc` folder of this repository](doc/).
+
+* Architectural overview
+  * [GitLab features that rely on Workhorse](doc/architecture/gitlab_features.md)
+  * [Websocket channel support](doc/architecture/channel.md)
+* Operating Workhorse
+  * [Source installation](doc/operations/install.md)
+  * [Workhorse configuration](doc/operations/configuration.md)
+* [Contributing](CONTRIBUTING.md)
+  * [Adding new features](doc/development/new_features.md)
+  * [Testing your code](doc/development/tests.md)
+
+## License
+
+This code is distributed under the MIT license, see the [LICENSE](LICENSE) file.
+

workhorse/VERSION

+8.57.0

workhorse/_support/changelog

+#!/usr/bin/env ruby
+#
+# Generate a changelog entry file in the correct location.
+#
+# Automatically stages the file and amends the previous commit if the `--amend`
+# argument is used.
+#
+# Stolen from gitlab-org/gitaly, lifted from gitlab-org/gitlab-ce
+
+require 'optparse'
+require 'yaml'
+
+Options = Struct.new(
+  :amend,
+  :author,
+  :dry_run,
+  :force,
+  :merge_request,
+  :title,
+  :type
+)
+INVALID_TYPE = -1
+
+class ChangelogOptionParser
+  Type = Struct.new(:name, :description)
+  TYPES = [
+    Type.new('added', 'New feature'),
+    Type.new('fixed', 'Bug fix'),
+    Type.new('changed', 'Feature change'),
+    Type.new('deprecated', 'New deprecation'),
+    Type.new('removed', 'Feature removal'),
+    Type.new('security', 'Security fix'),
+    Type.new('performance', 'Performance improvement'),
+    Type.new('other', 'Other')
+  ].freeze
+  TYPES_OFFSET = 1
+
+  class << self
+    def parse(argv)
+      options = Options.new
+
+      parser = OptionParser.new do |opts|
+        opts.banner = "Usage: #{__FILE__} [options] [title]\n\n"
+
+        # Note: We do not provide a shorthand for this in order to match the `git
+        # commit` interface
+        opts.on('--amend', 'Amend the previous commit') do |value|
+          options.amend = value
+        end
+
+        opts.on('-f', '--force', 'Overwrite an existing entry') do |value|
+          options.force = value
+        end
+
+        opts.on('-m', '--merge-request [integer]', Integer, 'Merge Request ID') do |value|
+          options.merge_request = value
+        end
+
+        opts.on('-n', '--dry-run', "Don't actually write anything, just print") do |value|
+          options.dry_run = value
+        end
+
+        opts.on('-u', '--git-username', 'Use Git user.name configuration as the author') do |value|
+          options.author = git_user_name if value
+        end
+
+        opts.on('-t', '--type [string]', String, "The category of the change, valid options are: #{TYPES.map(&:name).join(', ')}") do |value|
+          options.type = parse_type(value)
+        end
+
+        opts.on('-h', '--help', 'Print help message') do
+          $stdout.puts opts
+          exit
+        end
+      end
+
+      parser.parse!(argv)
+
+      # Title is everything that remains, but let's clean it up a bit
+      options.title = argv.join(' ').strip.squeeze(' ').tr("\r\n", '')
+
+      options
+    end
+
+    def read_type
+      read_type_message
+
+      type = TYPES[$stdin.getc.to_i - TYPES_OFFSET]
+      assert_valid_type!(type)
+
+      type.name
+    end
+
+    private
+
+    def parse_type(name)
+      type_found = TYPES.find do |type|
+        type.name == name
+      end
+      type_found ? type_found.name : INVALID_TYPE
+    end
+
+    def read_type_message
+      $stdout.puts "\n>> Please specify the index for the category of your change:"
+      TYPES.each_with_index do |type, index|
+        $stdout.puts "#{index + TYPES_OFFSET}. #{type.description}"
+      end
+      $stdout.print "\n?> "
+    end
+
+    def assert_valid_type!(type)
+      unless type
+        $stderr.puts "Invalid category index, please select an index between 1 and #{TYPES.length}"
+        exit 1
+      end
+    end
+
+    def git_user_name
+      %x{git config user.name}.strip
+    end
+  end
+end
+
+class ChangelogEntry
+  attr_reader :options
+
+  def initialize(options)
+    @options = options
+
+    assert_feature_branch!
+    assert_title!
+    assert_new_file!
+
+    # Read type from $stdin unless is already set
+    options.type ||= ChangelogOptionParser.read_type
+    assert_valid_type!
+
+    $stdout.puts "\e[32mcreate\e[0m #{file_path}"
+    $stdout.puts contents
+
+    unless options.dry_run
+      write
+      amend_commit if options.amend
+    end
+  end
+
+  private
+
+  def contents
+    yaml_content = YAML.dump(
+      'title'         => title,
+      'merge_request' => options.merge_request,
+      'author'        => options.author,
+      'type'          => options.type
+    )
+    remove_trailing_whitespace(yaml_content)
+  end
+
+  def write
+    File.write(file_path, contents)
+  end
+
+  def amend_commit
+    %x{git add #{file_path}}
+    exec("git commit --amend")
+  end
+
+  def fail_with(message)
+    $stderr.puts "\e[31merror\e[0m #{message}"
+    exit 1
+  end
+
+  def assert_feature_branch!
+    return unless branch_name == 'master'
+
+    fail_with "Create a branch first!"
+  end
+
+  def assert_new_file!
+    return unless File.exist?(file_path)
+    return if options.force
+
+    fail_with "#{file_path} already exists! Use `--force` to overwrite."
+  end
+
+  def assert_title!
+    return if options.title.length > 0 || options.amend
+
+    fail_with "Provide a title for the changelog entry or use `--amend`" \
+      " to use the title from the previous commit."
+  end
+
+  def assert_valid_type!
+    return unless options.type && options.type == INVALID_TYPE
+
+    fail_with 'Invalid category given!'
+  end
+
+  def title
+    if options.title.empty?
+      last_commit_subject
+    else
+      options.title
+    end
+  end
+
+  def last_commit_subject
+    %x{git log --format="%s" -1}.strip
+  end
+
+  def file_path
+    File.join(
+      unreleased_path,
+      branch_name.gsub(/[^\w-]/, '-') << '.yml'
+    )
+  end
+
+  def unreleased_path
+    path = File.join('changelogs', 'unreleased')
+    path = File.join('ee', path) if ee?
+
+    path
+  end
+
+  def ee?
+    @ee ||= File.exist?(File.expand_path('../CHANGELOG-EE.md', __dir__))
+  end
+
+  def branch_name
+    @branch_name ||= %x{git symbolic-ref --short HEAD}.strip
+  end
+
+  def remove_trailing_whitespace(yaml_content)
+    yaml_content.gsub(/ +$/, '')
+  end
+end
+
+if $0 == __FILE__
+  options = ChangelogOptionParser.parse(ARGV)
+  ChangelogEntry.new(options)
+end
+
+# vim: ft=ruby

workhorse/_support/check_changelog.sh

+#!/bin/sh
+
+set -e
+
+# we skip the changelog check if the merge requet title ends with "NO CHANGELOG"
+if echo "$CI_MERGE_REQUEST_TITLE" | grep -q ' NO CHANGELOG$'; then
+    echo "Changelog not needed"
+
+    exit 0
+fi
+
+target=${CI_MERGE_REQUEST_TARGET_BRANCH_NAME:-master}
+
+if git diff --name-only "origin/$target" | grep -q '^changelogs/' ; then
+    echo "Changelog included"
+else
+    echo "Please add a changelog running '_support/changelog'"
+    echo "or disable this check adding 'NO CHANGELOG' at the end of the merge request title"
+    echo "/title $CI_MERGE_REQUEST_TITLE NO CHANGELOG"
+
+    exit 1
+fi

workhorse/_support/detect-assert.sh

+#!/bin/sh
+
+git grep 'testify/assert"' | \
+    grep -e '^[^:]*\.go' | \
+    awk '{
+  print "error: please use testify/require instead of testify/assert"
+  print
+  exit 1
+}'

workhorse/_support/detect-context.sh

+#!/bin/sh
+
+git grep 'context.\(Background\|TODO\)' | \
+    grep -v -e '^[^:]*_test\.go:' -v -e "lint:allow context.Background" -e '^vendor/' -e '^_support/' -e '^cmd/[^:]*/main.go' | \
+    grep -e '^[^:]*\.go' | \
+    awk '{
+  print "Found disallowed use of context.Background or TODO"
+  print
+  exit 1
+}'

workhorse/_support/fake-auth-backend.go

+package main
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+
+	"gitlab.com/gitlab-org/labkit/log"
+)
+
+func main() {
+	if len(os.Args) == 1 {
+		fmt.Fprintf(os.Stderr, "Usage: %s /path/to/test-repo.git\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprintf(w, `{"RepoPath":"%s","ArchivePath":"%s"}`, os.Args[1], r.URL.Path)
+	})
+
+	log.Fatal(http.ListenAndServe("localhost:8080", nil))
+}

workhorse/_support/generate_changelog

+#!/usr/bin/env ruby
+# Generates the changelog from the yaml entries in changelogs/unreleased
+#
+# Lifted form gitlab-org/gitaly
+
+require 'yaml'
+require 'fileutils'
+
+class ChangelogEntry
+  attr_reader :title, :merge_request, :type, :author
+
+  def initialize(file_path)
+    yaml = YAML.safe_load(File.read(file_path))
+
+    @title = yaml['title']
+    @merge_request = yaml['merge_request']
+    @type = yaml['type']
+    @author = yaml['author']
+  end
+
+  def to_s
+    str = ""
+    str << "- #{title}\n"
+    str << "  https://gitlab.com/gitlab-org/gitlab-workhorse/-/merge_requests/#{merge_request}\n"
+    str << "  Contributed by #{author}\n" if author
+
+    str
+  end
+end
+
+ROOT_DIR = File.expand_path('../..', __FILE__)
+UNRELEASED_ENTRIES = File.join(ROOT_DIR, 'changelogs', 'unreleased')
+CHANGELOG_FILE = File.join(ROOT_DIR, 'CHANGELOG')
+
+def main(version)
+  entries = []
+  Dir["#{UNRELEASED_ENTRIES}/*.yml"].each do |yml|
+    entries << ChangelogEntry.new(yml)
+    FileUtils.rm(yml)
+  end
+
+  sections = []
+  types = entries.map(&:type).uniq.sort
+  types.each do |type|
+    text = ''
+    text << "### #{type.capitalize}\n"
+
+    entries.each do |e|
+      next unless e.type == type
+
+      text << e.to_s
+    end
+
+    sections << text
+  end
+
+  sections << '- No changes.' if sections.empty?
+
+  new_version_entry = ["## v#{version}\n\n", sections.join("\n"), "\n"].join
+
+  current_changelog = File.read(CHANGELOG_FILE).lines
+  header = current_changelog.shift(2)
+
+  new_changelog = [header, new_version_entry, current_changelog.join]
+
+  File.write(CHANGELOG_FILE, new_changelog.join)
+end
+
+unless ARGV.count == 1
+  warn "Usage: #{$0} VERSION"
+  warn "Specify version as x.y.z"
+  abort
+end
+
+main(ARGV.first)

workhorse/_support/lint.sh

+#!/bin/sh
+
+# Unfortunately, workhorse fails many lint checks which we currently ignore
+LINT_RESULT=$(golint "$@"|grep -Ev 'should have|should be|use ALL_CAPS in Go names')
+
+if [ -n "${LINT_RESULT}" ]; then
+  echo >&2 "Formatting or imports need fixing: 'make fmt'"
+  echo ">>${LINT_RESULT}<<"
+  exit 1
+fi
+

workhorse/_support/tag.sh

+set -e
+
+main() {
+  version=$1
+  set_version
+
+  changelog
+
+  git commit VERSION -m "Update VERSION to $version"
+
+  tag_name="v${version}"
+  git tag $TAG_OPTS -m "Version ${version}" -a ${tag_name}
+  git show ${tag_name}
+  cat <<'EOF'
+
+  Remember to now push your tag, either to gitlab.com (for a
+  normal release) or dev.gitlab.org (for a security release).
+EOF
+}
+
+set_version() {
+  if ! echo "${version}" | grep -q '^[0-9]\+\.[0-9]\+\.[0-9]\+$' ; then
+    echo "Invalid VERSION: ${version}"
+    exit 1
+  fi
+
+  if git tag --list | grep -q "^v${version}$" ; then
+    echo "Tag already exists for ${version}"
+    exit 1
+  fi
+
+  echo "$version" > VERSION
+}
+
+changelog() {
+  _support/generate_changelog "$version"
+
+  git commit CHANGELOG changelogs/unreleased --file - <<EOF
+Update CHANGELOG for ${version}
+
+[ci skip]
+EOF
+}
+
+main "$@"

workhorse/_support/validate-formatting.sh

+#!/bin/sh
+
+IMPORT_RESULT=$(goimports -e -local "gitlab.com/gitlab-org/gitlab-workhorse" -l "$@")
+
+if [ -n "${IMPORT_RESULT}" ]; then
+  echo >&2 "Formatting or imports need fixing: 'make fmt'"
+  echo "${IMPORT_RESULT}"
+  exit 1
+fi

workhorse/authorization_test.go

+package main
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"regexp"
+	"testing"
+
+	"gitlab.com/gitlab-org/labkit/correlation"
+
+	"github.com/dgrijalva/jwt-go"
+	"github.com/stretchr/testify/require"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/api"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/secret"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/testhelper"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/upstream/roundtripper"
+)
+
+func okHandler(w http.ResponseWriter, _ *http.Request, _ *api.Response) {
+	w.WriteHeader(201)
+	fmt.Fprint(w, "{\"status\":\"ok\"}")
+}
+
+func runPreAuthorizeHandler(t *testing.T, ts *httptest.Server, suffix string, url *regexp.Regexp, apiResponse interface{}, returnCode, expectedCode int) *httptest.ResponseRecorder {
+	if ts == nil {
+		ts = testAuthServer(t, url, nil, returnCode, apiResponse)
+		defer ts.Close()
+	}
+
+	// Create http request
+	ctx := correlation.ContextWithCorrelation(context.Background(), "12345678")
+	httpRequest, err := http.NewRequestWithContext(ctx, "GET", "/address", nil)
+	require.NoError(t, err)
+	parsedURL := helper.URLMustParse(ts.URL)
+	testhelper.ConfigureSecret()
+	a := api.NewAPI(parsedURL, "123", roundtripper.NewTestBackendRoundTripper(parsedURL))
+
+	response := httptest.NewRecorder()
+	a.PreAuthorizeHandler(okHandler, suffix).ServeHTTP(response, httpRequest)
+	require.Equal(t, expectedCode, response.Code)
+	return response
+}
+
+func TestPreAuthorizeHappyPath(t *testing.T) {
+	runPreAuthorizeHandler(
+		t, nil, "/authorize",
+		regexp.MustCompile(`/authorize\z`),
+		&api.Response{},
+		200, 201)
+}
+
+func TestPreAuthorizeSuffix(t *testing.T) {
+	runPreAuthorizeHandler(
+		t, nil, "/different-authorize",
+		regexp.MustCompile(`/authorize\z`),
+		&api.Response{},
+		200, 404)
+}
+
+func TestPreAuthorizeJsonFailure(t *testing.T) {
+	runPreAuthorizeHandler(
+		t, nil, "/authorize",
+		regexp.MustCompile(`/authorize\z`),
+		"not-json",
+		200, 500)
+}
+
+func TestPreAuthorizeContentTypeFailure(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, err := w.Write([]byte(`{"hello":"world"}`))
+		require.NoError(t, err, "write auth response")
+	}))
+	defer ts.Close()
+
+	runPreAuthorizeHandler(
+		t, ts, "/authorize",
+		regexp.MustCompile(`/authorize\z`),
+		"",
+		200, 200)
+}
+
+func TestPreAuthorizeRedirect(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.Redirect(w, r, "/", http.StatusMovedPermanently)
+	}))
+	defer ts.Close()
+
+	runPreAuthorizeHandler(t, ts, "/willredirect",
+		regexp.MustCompile(`/willredirect\z`),
+		"",
+		301, 301)
+}
+
+func TestPreAuthorizeJWT(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		token, err := jwt.Parse(r.Header.Get(secret.RequestHeader), func(token *jwt.Token) (interface{}, error) {
+			// Don't forget to validate the alg is what you expect:
+			if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+				return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
+			}
+			testhelper.ConfigureSecret()
+			secretBytes, err := secret.Bytes()
+			if err != nil {
+				return nil, fmt.Errorf("read secret from file: %v", err)
+			}
+
+			return secretBytes, nil
+		})
+		require.NoError(t, err, "decode token")
+
+		claims, ok := token.Claims.(jwt.MapClaims)
+		require.True(t, ok, "claims cast")
+		require.True(t, token.Valid, "JWT token valid")
+		require.Equal(t, "gitlab-workhorse", claims["iss"], "JWT token issuer")
+
+		w.Header().Set("Content-Type", api.ResponseContentType)
+		_, err = w.Write([]byte(`{"hello":"world"}`))
+		require.NoError(t, err, "write auth response")
+	}))
+	defer ts.Close()
+
+	runPreAuthorizeHandler(
+		t, ts, "/authorize",
+		regexp.MustCompile(`/authorize\z`),
+		"",
+		200, 201)
+}

workhorse/backend.go

+package main
+
+import (
+	"fmt"
+	"net/url"
+)
+
+func parseAuthBackend(authBackend string) (*url.URL, error) {
+	backendURL, err := url.Parse(authBackend)
+	if err != nil {
+		return nil, err
+	}
+
+	if backendURL.Host == "" {
+		backendURL, err = url.Parse("http://" + authBackend)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if backendURL.Scheme != "http" {
+		return nil, fmt.Errorf("invalid scheme, only 'http' is allowed: %q", authBackend)
+	}
+
+	if backendURL.Host == "" {
+		return nil, fmt.Errorf("missing host in %q", authBackend)
+	}
+
+	return backendURL, nil
+}

workhorse/backend_test.go

+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseAuthBackendFailure(t *testing.T) {
+	failures := []string{
+		"",
+		"ftp://localhost",
+		"https://example.com",
+	}
+
+	for _, example := range failures {
+		t.Run(example, func(t *testing.T) {
+			_, err := parseAuthBackend(example)
+			require.Error(t, err)
+		})
+	}
+}
+
+func TestParseAuthBackend(t *testing.T) {
+	successes := []struct{ input, host, scheme string }{
+		{"http://localhost:8080", "localhost:8080", "http"},
+		{"localhost:3000", "localhost:3000", "http"},
+		{"http://localhost", "localhost", "http"},
+		{"localhost", "localhost", "http"},
+	}
+
+	for _, example := range successes {
+		t.Run(example.input, func(t *testing.T) {
+			result, err := parseAuthBackend(example.input)
+			require.NoError(t, err)
+
+			require.Equal(t, example.host, result.Host, "host")
+			require.Equal(t, example.scheme, result.Scheme, "scheme")
+		})
+	}
+}

workhorse/cable_test.go

+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"regexp"
+	"testing"
+
+	"github.com/gorilla/websocket"
+	"github.com/stretchr/testify/require"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/config"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/testhelper"
+)
+
+const cablePath = "/-/cable"
+
+func TestSingleBackend(t *testing.T) {
+	cableServerConns, cableBackendServer := startCableServer()
+	defer cableBackendServer.Close()
+
+	config := newUpstreamWithCableConfig(cableBackendServer.URL, "")
+	workhorse := startWorkhorseServerWithConfig(config)
+	defer workhorse.Close()
+
+	cableURL := websocketURL(workhorse.URL, cablePath)
+
+	client, _, err := dialWebsocket(cableURL, nil)
+	require.NoError(t, err)
+	defer client.Close()
+
+	server := (<-cableServerConns).conn
+	defer server.Close()
+
+	require.NoError(t, say(client, "hello"))
+	requireReadMessage(t, server, websocket.TextMessage, "hello")
+
+	require.NoError(t, say(server, "world"))
+	requireReadMessage(t, client, websocket.TextMessage, "world")
+}
+
+func TestSeparateCableBackend(t *testing.T) {
+	authBackendServer := testhelper.TestServerWithHandler(regexp.MustCompile(`.`), http.HandlerFunc(http.NotFound))
+	defer authBackendServer.Close()
+
+	cableServerConns, cableBackendServer := startCableServer()
+	defer cableBackendServer.Close()
+
+	config := newUpstreamWithCableConfig(authBackendServer.URL, cableBackendServer.URL)
+	workhorse := startWorkhorseServerWithConfig(config)
+	defer workhorse.Close()
+
+	cableURL := websocketURL(workhorse.URL, cablePath)
+
+	client, _, err := dialWebsocket(cableURL, nil)
+	require.NoError(t, err)
+	defer client.Close()
+
+	server := (<-cableServerConns).conn
+	defer server.Close()
+
+	require.NoError(t, say(client, "hello"))
+	requireReadMessage(t, server, websocket.TextMessage, "hello")
+
+	require.NoError(t, say(server, "world"))
+	requireReadMessage(t, client, websocket.TextMessage, "world")
+}
+
+func startCableServer() (chan connWithReq, *httptest.Server) {
+	upgrader := &websocket.Upgrader{}
+
+	connCh := make(chan connWithReq, 1)
+	server := testhelper.TestServerWithHandler(regexp.MustCompile(cablePath), webSocketHandler(upgrader, connCh))
+
+	return connCh, server
+}
+
+func newUpstreamWithCableConfig(authBackend string, cableBackend string) *config.Config {
+	var cableBackendURL *url.URL
+
+	if cableBackend != "" {
+		cableBackendURL = helper.URLMustParse(cableBackend)
+	}
+
+	return &config.Config{
+		Version:      "123",
+		DocumentRoot: testDocumentRoot,
+		Backend:      helper.URLMustParse(authBackend),
+		CableBackend: cableBackendURL,
+	}
+}

workhorse/channel_test.go

+package main
+
+import (
+	"bytes"
+	"encoding/pem"
+	"fmt"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"path"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/gorilla/websocket"
+	"github.com/stretchr/testify/require"
+	"gitlab.com/gitlab-org/labkit/log"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/api"
+)
+
+var (
+	envTerminalPath     = fmt.Sprintf("%s/-/environments/1/terminal.ws", testProject)
+	jobTerminalPath     = fmt.Sprintf("%s/-/jobs/1/terminal.ws", testProject)
+	servicesProxyWSPath = fmt.Sprintf("%s/-/jobs/1/proxy.ws", testProject)
+)
+
+type connWithReq struct {
+	conn *websocket.Conn
+	req  *http.Request
+}
+
+func TestChannelHappyPath(t *testing.T) {
+	tests := []struct {
+		name        string
+		channelPath string
+	}{
+		{"environments", envTerminalPath},
+		{"jobs", jobTerminalPath},
+		{"services", servicesProxyWSPath},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			serverConns, clientURL, close := wireupChannel(t, test.channelPath, nil, "channel.k8s.io")
+			defer close()
+
+			client, _, err := dialWebsocket(clientURL, nil, "terminal.gitlab.com")
+			require.NoError(t, err)
+
+			server := (<-serverConns).conn
+			defer server.Close()
+
+			message := "test message"
+
+			// channel.k8s.io: server writes to channel 1, STDOUT
+			require.NoError(t, say(server, "\x01"+message))
+			requireReadMessage(t, client, websocket.BinaryMessage, message)
+
+			require.NoError(t, say(client, message))
+
+			// channel.k8s.io: client writes get put on channel 0, STDIN
+			requireReadMessage(t, server, websocket.BinaryMessage, "\x00"+message)
+
+			// Closing the client should send an EOT signal to the server's STDIN
+			client.Close()
+			requireReadMessage(t, server, websocket.BinaryMessage, "\x00\x04")
+		})
+	}
+}
+
+func TestChannelBadTLS(t *testing.T) {
+	_, clientURL, close := wireupChannel(t, envTerminalPath, badCA, "channel.k8s.io")
+	defer close()
+
+	_, _, err := dialWebsocket(clientURL, nil, "terminal.gitlab.com")
+	require.Equal(t, websocket.ErrBadHandshake, err, "unexpected error %v", err)
+}
+
+func TestChannelSessionTimeout(t *testing.T) {
+	serverConns, clientURL, close := wireupChannel(t, envTerminalPath, timeout, "channel.k8s.io")
+	defer close()
+
+	client, _, err := dialWebsocket(clientURL, nil, "terminal.gitlab.com")
+	require.NoError(t, err)
+
+	sc := <-serverConns
+	defer sc.conn.Close()
+
+	client.SetReadDeadline(time.Now().Add(time.Duration(2) * time.Second))
+	_, _, err = client.ReadMessage()
+
+	require.True(t, websocket.IsCloseError(err, websocket.CloseAbnormalClosure), "Client connection was not closed, got %v", err)
+}
+
+func TestChannelProxyForwardsHeadersFromUpstream(t *testing.T) {
+	hdr := make(http.Header)
+	hdr.Set("Random-Header", "Value")
+	serverConns, clientURL, close := wireupChannel(t, envTerminalPath, setHeader(hdr), "channel.k8s.io")
+	defer close()
+
+	client, _, err := dialWebsocket(clientURL, nil, "terminal.gitlab.com")
+	require.NoError(t, err)
+	defer client.Close()
+
+	sc := <-serverConns
+	defer sc.conn.Close()
+	require.Equal(t, "Value", sc.req.Header.Get("Random-Header"), "Header specified by upstream not sent to remote")
+}
+
+func TestChannelProxyForwardsXForwardedForFromClient(t *testing.T) {
+	serverConns, clientURL, close := wireupChannel(t, envTerminalPath, nil, "channel.k8s.io")
+	defer close()
+
+	hdr := make(http.Header)
+	hdr.Set("X-Forwarded-For", "127.0.0.2")
+	client, _, err := dialWebsocket(clientURL, hdr, "terminal.gitlab.com")
+	require.NoError(t, err)
+	defer client.Close()
+
+	clientIP, _, err := net.SplitHostPort(client.LocalAddr().String())
+	require.NoError(t, err)
+
+	sc := <-serverConns
+	defer sc.conn.Close()
+
+	require.Equal(t, "127.0.0.2, "+clientIP, sc.req.Header.Get("X-Forwarded-For"), "X-Forwarded-For from client not sent to remote")
+}
+
+func wireupChannel(t *testing.T, channelPath string, modifier func(*api.Response), subprotocols ...string) (chan connWithReq, string, func()) {
+	serverConns, remote := startWebsocketServer(subprotocols...)
+	authResponse := channelOkBody(remote, nil, subprotocols...)
+	if modifier != nil {
+		modifier(authResponse)
+	}
+	upstream := testAuthServer(t, nil, nil, 200, authResponse)
+	workhorse := startWorkhorseServer(upstream.URL)
+
+	return serverConns, websocketURL(workhorse.URL, channelPath), func() {
+		workhorse.Close()
+		upstream.Close()
+		remote.Close()
+	}
+}
+
+func startWebsocketServer(subprotocols ...string) (chan connWithReq, *httptest.Server) {
+	upgrader := &websocket.Upgrader{Subprotocols: subprotocols}
+
+	connCh := make(chan connWithReq, 1)
+	server := httptest.NewTLSServer(webSocketHandler(upgrader, connCh))
+
+	return connCh, server
+}
+
+func webSocketHandler(upgrader *websocket.Upgrader, connCh chan connWithReq) http.HandlerFunc {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		logEntry := log.WithFields(log.Fields{
+			"method":  r.Method,
+			"url":     r.URL,
+			"headers": r.Header,
+		})
+
+		logEntry.Info("WEBSOCKET")
+		conn, err := upgrader.Upgrade(w, r, nil)
+		if err != nil {
+			logEntry.WithError(err).Error("WEBSOCKET Upgrade failed")
+			return
+		}
+		connCh <- connWithReq{conn, r}
+		// The connection has been hijacked so it's OK to end here
+	})
+}
+
+func channelOkBody(remote *httptest.Server, header http.Header, subprotocols ...string) *api.Response {
+	out := &api.Response{
+		Channel: &api.ChannelSettings{
+			Url:            websocketURL(remote.URL),
+			Header:         header,
+			Subprotocols:   subprotocols,
+			MaxSessionTime: 0,
+		},
+	}
+
+	if len(remote.TLS.Certificates) > 0 {
+		data := bytes.NewBuffer(nil)
+		pem.Encode(data, &pem.Block{Type: "CERTIFICATE", Bytes: remote.TLS.Certificates[0].Certificate[0]})
+		out.Channel.CAPem = data.String()
+	}
+
+	return out
+}
+
+func badCA(authResponse *api.Response) {
+	authResponse.Channel.CAPem = "Bad CA"
+}
+
+func timeout(authResponse *api.Response) {
+	authResponse.Channel.MaxSessionTime = 1
+}
+
+func setHeader(hdr http.Header) func(*api.Response) {
+	return func(authResponse *api.Response) {
+		authResponse.Channel.Header = hdr
+	}
+}
+
+func dialWebsocket(url string, header http.Header, subprotocols ...string) (*websocket.Conn, *http.Response, error) {
+	dialer := &websocket.Dialer{
+		Subprotocols: subprotocols,
+	}
+
+	return dialer.Dial(url, header)
+}
+
+func websocketURL(httpURL string, suffix ...string) string {
+	url, err := url.Parse(httpURL)
+	if err != nil {
+		panic(err)
+	}
+
+	switch url.Scheme {
+	case "http":
+		url.Scheme = "ws"
+	case "https":
+		url.Scheme = "wss"
+	default:
+		panic("Unknown scheme: " + url.Scheme)
+	}
+
+	url.Path = path.Join(url.Path, strings.Join(suffix, "/"))
+
+	return url.String()
+}
+
+func say(conn *websocket.Conn, message string) error {
+	return conn.WriteMessage(websocket.TextMessage, []byte(message))
+}
+
+func requireReadMessage(t *testing.T, conn *websocket.Conn, expectedMessageType int, expectedData string) {
+	messageType, data, err := conn.ReadMessage()
+	require.NoError(t, err)
+
+	require.Equal(t, expectedMessageType, messageType, "message type")
+	require.Equal(t, expectedData, string(data), "message data")
+}

workhorse/cmd/gitlab-resize-image/main.go

+package main
+
+import (
+	"fmt"
+	"image"
+	"os"
+	"strconv"
+
+	"github.com/disintegration/imaging"
+)
+
+func main() {
+	if err := _main(); err != nil {
+		fmt.Fprintf(os.Stderr, "%s: fatal: %v\n", os.Args[0], err)
+		os.Exit(1)
+	}
+}
+
+func _main() error {
+	widthParam := os.Getenv("GL_RESIZE_IMAGE_WIDTH")
+	requestedWidth, err := strconv.Atoi(widthParam)
+	if err != nil {
+		return fmt.Errorf("GL_RESIZE_IMAGE_WIDTH: %w", err)
+	}
+
+	src, formatName, err := image.Decode(os.Stdin)
+	if err != nil {
+		return fmt.Errorf("decode: %w", err)
+	}
+	imagingFormat, err := imaging.FormatFromExtension(formatName)
+	if err != nil {
+		return fmt.Errorf("find imaging format: %w", err)
+	}
+
+	image := imaging.Resize(src, requestedWidth, 0, imaging.Lanczos)
+	return imaging.Encode(os.Stdout, image, imagingFormat)
+}

workhorse/cmd/gitlab-zip-cat/main.go

+package main
+
+import (
+	"archive/zip"
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+
+	"gitlab.com/gitlab-org/labkit/mask"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/zipartifacts"
+)
+
+const progName = "gitlab-zip-cat"
+
+var Version = "unknown"
+
+var printVersion = flag.Bool("version", false, "Print version and exit")
+
+func main() {
+	flag.Parse()
+
+	version := fmt.Sprintf("%s %s", progName, Version)
+	if *printVersion {
+		fmt.Println(version)
+		os.Exit(0)
+	}
+
+	archivePath := os.Getenv("ARCHIVE_PATH")
+	encodedFileName := os.Getenv("ENCODED_FILE_NAME")
+
+	if len(os.Args) != 1 || archivePath == "" || encodedFileName == "" {
+		fmt.Fprintf(os.Stderr, "Usage: %s\n", progName)
+		fmt.Fprintf(os.Stderr, "Env: ARCHIVE_PATH=https://path.to/archive.zip or /path/to/archive.zip\n")
+		fmt.Fprintf(os.Stderr, "Env: ENCODED_FILE_NAME=base64-encoded-file-name\n")
+		os.Exit(1)
+	}
+
+	scrubbedArchivePath := mask.URL(archivePath)
+
+	fileName, err := zipartifacts.DecodeFileEntry(encodedFileName)
+	if err != nil {
+		fatalError(fmt.Errorf("decode entry %q", encodedFileName), err)
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	archive, err := zipartifacts.OpenArchive(ctx, archivePath)
+	if err != nil {
+		fatalError(errors.New("open archive"), err)
+	}
+
+	file := findFileInZip(fileName, archive)
+	if file == nil {
+		fatalError(fmt.Errorf("find %q in %q: not found", fileName, scrubbedArchivePath), zipartifacts.ErrorCode[zipartifacts.CodeEntryNotFound])
+	}
+	// Start decompressing the file
+	reader, err := file.Open()
+	if err != nil {
+		fatalError(fmt.Errorf("open %q in %q", fileName, scrubbedArchivePath), err)
+	}
+	defer reader.Close()
+
+	if _, err := fmt.Printf("%d\n", file.UncompressedSize64); err != nil {
+		fatalError(fmt.Errorf("write file size invalid"), err)
+	}
+
+	if _, err := io.Copy(os.Stdout, reader); err != nil {
+		fatalError(fmt.Errorf("write %q from %q to stdout", fileName, scrubbedArchivePath), err)
+	}
+}
+
+func findFileInZip(fileName string, archive *zip.Reader) *zip.File {
+	for _, file := range archive.File {
+		if file.Name == fileName {
+			return file
+		}
+	}
+	return nil
+}
+
+func fatalError(contextErr error, statusErr error) {
+	code := zipartifacts.ExitCodeByError(statusErr)
+
+	fmt.Fprintf(os.Stderr, "%s error: %v - %v, code: %d\n", progName, statusErr, contextErr, code)
+
+	if code > 0 {
+		os.Exit(code)
+	} else {
+		os.Exit(1)
+	}
+}

workhorse/cmd/gitlab-zip-metadata/limit/reader.go

+package limit
+
+import (
+	"errors"
+	"io"
+	"sync/atomic"
+)
+
+var ErrLimitExceeded = errors.New("reader limit exceeded")
+
+const megabyte = 1 << 20
+
+// LimitedReaderAt supports running a callback in case of reaching a read limit
+// (bytes), and allows using a smaller limit than a defined offset for a read.
+type LimitedReaderAt struct {
+	read      int64
+	limit     int64
+	parent    io.ReaderAt
+	limitFunc func(int64)
+}
+
+func (r *LimitedReaderAt) ReadAt(p []byte, off int64) (int, error) {
+	if max := r.limit - r.read; int64(len(p)) > max {
+		p = p[0:max]
+	}
+
+	n, err := r.parent.ReadAt(p, off)
+	atomic.AddInt64(&r.read, int64(n))
+
+	if r.read >= r.limit {
+		r.limitFunc(r.read)
+
+		return n, ErrLimitExceeded
+	}
+
+	return n, err
+}
+
+func NewLimitedReaderAt(reader io.ReaderAt, limit int64, limitFunc func(int64)) io.ReaderAt {
+	return &LimitedReaderAt{parent: reader, limit: limit, limitFunc: limitFunc}
+}
+
+// SizeToLimit tries to dermine an appropriate limit in bytes for an archive of
+// a given size. If the size is less than 1 gigabyte we always limit a reader
+// to 100 megabytes, otherwise the limit is 10% of a given size.
+func SizeToLimit(size int64) int64 {
+	if size <= 1024*megabyte {
+		return 100 * megabyte
+	}
+
+	return size / 10
+}

workhorse/cmd/gitlab-zip-metadata/limit/reader_test.go

+package limit
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestReadAt(t *testing.T) {
+	t.Run("when limit has not been reached", func(t *testing.T) {
+		r := strings.NewReader("some string to read")
+		buf := make([]byte, 11)
+
+		reader := NewLimitedReaderAt(r, 32, func(n int64) {
+			require.Zero(t, n)
+		})
+		p, err := reader.ReadAt(buf, 0)
+
+		require.NoError(t, err)
+		require.Equal(t, 11, p)
+		require.Equal(t, "some string", string(buf))
+	})
+
+	t.Run("when read limit is exceeded", func(t *testing.T) {
+		r := strings.NewReader("some string to read")
+		buf := make([]byte, 11)
+
+		reader := NewLimitedReaderAt(r, 9, func(n int64) {
+			require.Equal(t, 9, int(n))
+		})
+		p, err := reader.ReadAt(buf, 0)
+
+		require.Error(t, err)
+		require.Equal(t, 9, p)
+		require.Equal(t, "some stri\x00\x00", string(buf))
+	})
+
+	t.Run("when offset is higher than a limit", func(t *testing.T) {
+		r := strings.NewReader("some string to read")
+		buf := make([]byte, 4)
+
+		reader := NewLimitedReaderAt(r, 5, func(n int64) {
+			require.Zero(t, n)
+		})
+
+		p, err := reader.ReadAt(buf, 15)
+
+		require.NoError(t, err)
+		require.Equal(t, 4, p)
+		require.Equal(t, "read", string(buf))
+	})
+
+	t.Run("when a read starts at the limit", func(t *testing.T) {
+		r := strings.NewReader("some string to read")
+		buf := make([]byte, 11)
+
+		reader := NewLimitedReaderAt(r, 10, func(n int64) {
+			require.Equal(t, 10, int(n))
+		})
+
+		reader.ReadAt(buf, 0)
+		p, err := reader.ReadAt(buf, 0)
+
+		require.EqualError(t, err, ErrLimitExceeded.Error())
+		require.Equal(t, 0, p)
+		require.Equal(t, "some strin\x00", string(buf))
+	})
+}
+
+func TestSizeToLimit(t *testing.T) {
+	tests := []struct {
+		size  int64
+		limit int64
+		name  string
+	}{
+		{size: 1, limit: 104857600, name: "1b to 100mb"},
+		{size: 100, limit: 104857600, name: "100b to 100mb"},
+		{size: 104857600, limit: 104857600, name: "100mb to 100mb"},
+		{size: 1073741824, limit: 104857600, name: "1gb to 100mb"},
+		{size: 10737418240, limit: 1073741824, name: "10gb to 1gb"},
+		{size: 53687091200, limit: 5368709120, name: "50gb to 5gb"},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			require.Equal(t, test.limit, SizeToLimit(test.size))
+		})
+	}
+}

workhorse/cmd/gitlab-zip-metadata/main.go

+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/cmd/gitlab-zip-metadata/limit"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/zipartifacts"
+)
+
+const progName = "gitlab-zip-metadata"
+
+var Version = "unknown"
+
+var printVersion = flag.Bool("version", false, "Print version and exit")
+
+func main() {
+	flag.Parse()
+
+	version := fmt.Sprintf("%s %s", progName, Version)
+	if *printVersion {
+		fmt.Println(version)
+		os.Exit(0)
+	}
+
+	if len(os.Args) != 2 {
+		fmt.Fprintf(os.Stderr, "Usage: %s FILE.ZIP\n", progName)
+		os.Exit(1)
+	}
+
+	readerFunc := func(reader io.ReaderAt, size int64) io.ReaderAt {
+		readLimit := limit.SizeToLimit(size)
+
+		return limit.NewLimitedReaderAt(reader, readLimit, func(read int64) {
+			fmt.Fprintf(os.Stderr, "%s: zip archive limit exceeded after reading %d bytes\n", progName, read)
+
+			fatalError(zipartifacts.ErrorCode[zipartifacts.CodeLimitsReached])
+		})
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	archive, err := zipartifacts.OpenArchiveWithReaderFunc(ctx, os.Args[1], readerFunc)
+	if err != nil {
+		fatalError(err)
+	}
+
+	if err := zipartifacts.GenerateZipMetadata(os.Stdout, archive); err != nil {
+		fatalError(err)
+	}
+}
+
+func fatalError(err error) {
+	code := zipartifacts.ExitCodeByError(err)
+
+	fmt.Fprintf(os.Stderr, "%s error: %v, code: %d\n", progName, err, code)
+
+	if code > 0 {
+		os.Exit(code)
+	} else {
+		os.Exit(1)
+	}
+}

workhorse/config.toml.example

+[redis]
+URL = "unix:/home/git/gitlab/redis/redis.socket"
+
+[object_storage]
+  provider = "AWS" # Allowed options: AWS, AzureRM
+
+[object_storage.s3]
+  aws_access_key_id = "YOUR AWS ACCESS KEY"
+  aws_secret_access_key = "YOUR AWS SECRET ACCESS KEY"
+
+[object_store.azurerm]
+  azure_storage_account_name = "YOUR ACCOUNT NAME"
+  azure_storage_access_key = "YOUR ACCOUNT KEY"
+
+[image_resizer]
+  max_scaler_procs = 4 # Recommendation: CPUs / 2
+  max_filesize = 250000

workhorse/config_test.go

+package main
+
+import (
+	"flag"
+	"io"
+	"io/ioutil"
+	"net/url"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/config"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/queueing"
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/upstream"
+)
+
+func TestConfigFile(t *testing.T) {
+	f, err := ioutil.TempFile("", "workhorse-config-test")
+	require.NoError(t, err)
+	defer os.Remove(f.Name())
+
+	data := `
+[redis]
+password = "redis password"
+[object_storage]
+provider = "test provider"
+[image_resizer]
+max_scaler_procs = 123
+`
+	_, err = io.WriteString(f, data)
+	require.NoError(t, err)
+	require.NoError(t, f.Close())
+
+	_, cfg, err := buildConfig("test", []string{"-config", f.Name()})
+	require.NoError(t, err, "build config")
+
+	// These are integration tests: we want to see that each section in the
+	// config file ends up in the config struct. We do not test all the
+	// fields in each section; that should happen in the tests of the
+	// internal/config package.
+	require.Equal(t, "redis password", cfg.Redis.Password)
+	require.Equal(t, "test provider", cfg.ObjectStorageCredentials.Provider)
+	require.Equal(t, uint32(123), cfg.ImageResizerConfig.MaxScalerProcs, "image resizer max_scaler_procs")
+}
+
+func TestConfigErrorHelp(t *testing.T) {
+	for _, f := range []string{"-h", "-help"} {
+		t.Run(f, func(t *testing.T) {
+			_, _, err := buildConfig("test", []string{f})
+			require.Equal(t, alreadyPrintedError{flag.ErrHelp}, err)
+		})
+	}
+}
+
+func TestConfigError(t *testing.T) {
+	for _, arg := range []string{"-foobar", "foobar"} {
+		t.Run(arg, func(t *testing.T) {
+			_, _, err := buildConfig("test", []string{arg})
+
+			require.Error(t, err)
+			require.IsType(t, alreadyPrintedError{}, err)
+		})
+	}
+}
+
+func TestConfigDefaults(t *testing.T) {
+	boot, cfg, err := buildConfig("test", nil)
+	require.NoError(t, err, "build config")
+
+	expectedBoot := &bootConfig{
+		secretPath:    "./.gitlab_workhorse_secret",
+		listenAddr:    "localhost:8181",
+		listenNetwork: "tcp",
+		logFormat:     "text",
+	}
+
+	require.Equal(t, expectedBoot, boot)
+
+	expectedCfg := &config.Config{
+		Backend:                  upstream.DefaultBackend,
+		CableBackend:             upstream.DefaultBackend,
+		Version:                  "(unknown version)",
+		DocumentRoot:             "public",
+		ProxyHeadersTimeout:      5 * time.Minute,
+		APIQueueTimeout:          queueing.DefaultTimeout,
+		APICILongPollingDuration: 50 * time.Nanosecond, // TODO this is meant to be 50*time.Second but it has been wrong for ages
+		ImageResizerConfig:       config.DefaultImageResizerConfig,
+	}
+
+	require.Equal(t, expectedCfg, cfg)
+}
+
+func TestConfigFlagParsing(t *testing.T) {
+	backendURL, err := url.Parse("http://localhost:1234")
+	require.NoError(t, err)
+	cableURL, err := url.Parse("http://localhost:5678")
+	require.NoError(t, err)
+
+	args := []string{
+		"-version",
+		"-secretPath", "secret path",
+		"-listenAddr", "listen addr",
+		"-listenNetwork", "listen network",
+		"-listenUmask", "123",
+		"-pprofListenAddr", "pprof listen addr",
+		"-prometheusListenAddr", "prometheus listen addr",
+		"-logFile", "log file",
+		"-logFormat", "log format",
+		"-documentRoot", "document root",
+		"-developmentMode",
+		"-authBackend", backendURL.String(),
+		"-authSocket", "auth socket",
+		"-cableBackend", cableURL.String(),
+		"-cableSocket", "cable socket",
+		"-proxyHeadersTimeout", "10m",
+		"-apiLimit", "234",
+		"-apiQueueLimit", "345",
+		"-apiQueueDuration", "123s",
+		"-apiCiLongPollingDuration", "234s",
+		"-propagateCorrelationID",
+	}
+	boot, cfg, err := buildConfig("test", args)
+	require.NoError(t, err, "build config")
+
+	expectedBoot := &bootConfig{
+		secretPath:           "secret path",
+		listenAddr:           "listen addr",
+		listenNetwork:        "listen network",
+		listenUmask:          123,
+		pprofListenAddr:      "pprof listen addr",
+		prometheusListenAddr: "prometheus listen addr",
+		logFile:              "log file",
+		logFormat:            "log format",
+		printVersion:         true,
+	}
+	require.Equal(t, expectedBoot, boot)
+
+	expectedCfg := &config.Config{
+		DocumentRoot:             "document root",
+		DevelopmentMode:          true,
+		Backend:                  backendURL,
+		Socket:                   "auth socket",
+		CableBackend:             cableURL,
+		CableSocket:              "cable socket",
+		Version:                  "(unknown version)",
+		ProxyHeadersTimeout:      10 * time.Minute,
+		APILimit:                 234,
+		APIQueueLimit:            345,
+		APIQueueTimeout:          123 * time.Second,
+		APICILongPollingDuration: 234 * time.Second,
+		PropagateCorrelationID:   true,
+		ImageResizerConfig:       config.DefaultImageResizerConfig,
+	}
+	require.Equal(t, expectedCfg, cfg)
+}

workhorse/doc/architecture/channel.md

+# Websocket channel support
+
+In some cases, GitLab can provide in-browser terminal access to an
+environment (which is a running server or container, onto which a
+project has been deployed), or even access to services running in CI
+through a WebSocket. Workhorse manages the WebSocket upgrade and
+long-lived connection to the websocket connection, which frees
+up GitLab to process other requests.
+
+This document outlines the architecture of these connections.
+
+## Introduction to WebSockets
+
+A websocket is an "upgraded" HTTP/1.1 request. Their purpose is to
+permit bidirectional communication between a client and a server.
+**Websockets are not HTTP**. Clients can send messages (known as
+frames) to the server at any time, and vice-versa. Client messages
+are not necessarily requests, and server messages are not necessarily
+responses. WebSocket URLs have schemes like `ws://` (unencrypted) or
+`wss://` (TLS-secured).
+
+When requesting an upgrade to WebSocket, the browser sends a HTTP/1.1
+request that looks like this:
+
+```
+GET /path.ws HTTP/1.1
+Connection: upgrade
+Upgrade: websocket
+Sec-WebSocket-Protocol: terminal.gitlab.com
+# More headers, including security measures
+```
+
+At this point, the connection is still HTTP, so this is a request and
+the server can send a normal HTTP response, including `404 Not Found`,
+`500 Internal Server Error`, etc.
+
+If the server decides to permit the upgrade, it will send a HTTP
+`101 Switching Protocols` response. From this point, the connection
+is no longer HTTP. It is a WebSocket and frames, not HTTP requests,
+will flow over it. The connection will persist until the client or
+server closes the connection.
+
+In addition to the subprotocol, individual websocket frames may
+also specify a message type - examples include `BinaryMessage`,
+`TextMessage`, `Ping`, `Pong` or `Close`. Only binary frames can
+contain arbitrary data - other frames are expected to be valid
+UTF-8 strings, in addition to any subprotocol expectations.
+
+## Browser to Workhorse
+
+Using the terminal as an example, GitLab serves a JavaScript terminal
+emulator to the browser on a URL like
+`https://gitlab.com/group/project/-/environments/1/terminal`.
+This opens a websocket connection to, e.g.,
+`wss://gitlab.com/group/project/-/environments/1/terminal.ws`,
+This endpoint doesn't exist in GitLab - only in Workhorse.
+
+When receiving the connection, Workhorse first checks that the
+client is authorized to access the requested terminal. It does
+this by performing a "preauthentication" request to GitLab.
+
+If the client has the appropriate permissions and the terminal
+exists, GitLab responds with a successful response that includes
+details of the terminal that the client should be connected to.
+Otherwise, it returns an appropriate HTTP error response.
+
+Errors are passed back to the client as HTTP responses, but if
+GitLab returns valid terminal details to Workhorse, it will
+connect to the specified terminal, upgrade the browser to a
+WebSocket, and proxy between the two connections for as long
+as the browser's credentials are valid. Workhorse will also
+send regular `PingMessage` control frames to the browser, to
+keep intervening proxies from terminating the connection
+while the browser is present.
+
+The browser must request an upgrade with a specific subprotocol:
+
+### `terminal.gitlab.com`
+
+This subprotocol considers `TextMessage` frames to be invalid.
+Control frames, such as `PingMessage` or `CloseMessage`, have
+their usual meanings.
+
+`BinaryMessage` frames sent from the browser to the server are
+arbitrary text input.
+
+`BinaryMessage` frames sent from the server to the browser are
+arbitrary text output.
+
+These frames are expected to contain ANSI text control codes
+and may be in any encoding.
+
+### `base64.terminal.gitlab.com`
+
+This subprotocol considers `BinaryMessage` frames to be invalid.
+Control frames, such as `PingMessage` or `CloseMessage`, have
+their usual meanings.
+
+`TextMessage` frames sent from the browser to the server are
+base64-encoded arbitrary text input (so the server must
+base64-decode them before inputting them).
+
+`TextMessage` frames sent from the server to the browser are
+base64-encoded arbitrary text output (so the browser must
+base64-decode them before outputting them).
+
+In their base64-encoded form, these frames are expected to
+contain ANSI terminal control codes, and may be in any encoding.
+
+## Workhorse to GitLab
+
+Using again the terminal as an example, before upgrading the browser,
+Workhorse sends a normal HTTP request to GitLab on a URL like
+`https://gitlab.com/group/project/environments/1/terminal.ws/authorize`.
+This returns a JSON response containing details of where the
+terminal can be found, and how to connect it. In particular,
+the following details are returned in case of success:
+
+* WebSocket URL to **connect** to, e.g.: `wss://example.com/terminals/1.ws?tty=1`
+* WebSocket subprotocols to support, e.g.: `["channel.k8s.io"]`
+* Headers to send, e.g.: `Authorization: Token xxyyz..`
+* Certificate authority to verify `wss` connections with (optional)
+
+Workhorse periodically re-checks this endpoint, and if it gets an
+error response, or the details of the terminal change, it will
+terminate the websocket session.
+
+## Workhorse to the WebSocket server
+
+In GitLab, environments or CI jobs may have a deployment service (e.g.,
+`KubernetesService`) associated with them. This service knows
+where the terminals or the service for an environment may be found, and these
+details are returned to Workhorse by GitLab.
+
+These URLs are *also* WebSocket URLs, and GitLab tells Workhorse
+which subprotocols to speak over the connection, along with any
+authentication details required by the remote end.
+
+Before upgrading the browser's connection to a websocket,
+Workhorse opens a HTTP client connection, according to the
+details given to it by Workhorse, and attempts to upgrade
+that connection to a websocket. If it fails, an error
+response is sent to the browser; otherwise, the browser is
+also upgraded.
+
+Workhorse now has two websocket connections, albeit with
+differing subprotocols. It decodes incoming frames from the
+browser, re-encodes them to the the channel's subprotocol, and
+sends them to the channel. Similarly, it decodes incoming
+frames from the channel, re-encodes them to the browser's
+subprotocol, and sends them to the browser.
+
+When either connection closes or enters an error state,
+Workhorse detects the error and closes the other connection,
+terminating the channel session. If the browser is the
+connection that has disconnected, Workhorse will send an ANSI
+`End of Transmission` control code (the `0x04` byte) to the
+channel, encoded according to the appropriate subprotocol.
+Workhorse will automatically reply to any websocket ping frame
+sent by the channel, to avoid being disconnected.
+
+Currently, Workhorse only supports the following subprotocols.
+Supporting new deployment services will require new subprotocols
+to be supported:
+
+### `channel.k8s.io`
+
+Used by Kubernetes, this subprotocol defines a simple multiplexed
+channel.
+
+Control frames have their usual meanings. `TextMessage` frames are
+invalid. `BinaryMessage` frames represent I/O to a specific file
+descriptor.
+
+The first byte of each `BinaryMessage` frame represents the file
+descriptor (fd) number, as a `uint8` (so the value `0x00` corresponds
+to fd 0, `STDIN`, while `0x01` corresponds to fd 1, `STDOUT`).
+
+The remaining bytes represent arbitrary data. For frames received
+from the server, they are bytes that have been received from that
+fd. For frames sent to the server, they are bytes that should be
+written to that fd.
+
+### `base64.channel.k8s.io`
+
+Also used by Kubernetes, this subprotocol defines a similar multiplexed
+channel to `channel.k8s.io`. The main differences are:
+
+* `TextMessage` frames are valid, rather than `BinaryMessage` frames.
+* The first byte of each `TextMessage` frame represents the file
+  descriptor as a numeric UTF-8 character, so the character `U+0030`,
+  or "0", is fd 0, STDIN).
+* The remaining bytes represent base64-encoded arbitrary data.
+

workhorse/doc/architecture/gitlab_features.md

+# Features that rely on Workhorse
+
+Workhorse itself is not a feature, but there are several features in
+GitLab that would not work efficiently without Workhorse.
+
+To put the efficiency benefit in context, consider that in 2020Q3 on
+GitLab.com [we see][thanos] Rails application threads using on average
+about 200MB of RSS vs about 200KB for Workhorse goroutines.
+
+Examples of features that rely on Workhorse:
+
+## 1. `git clone` and `git push` over HTTP
+
+Git clone, pull and push are slow because they transfer large amounts
+of data and because each is CPU intensive on the GitLab side. Without
+Workhorse, HTTP access to Git repositories would compete with regular
+web access to the application, requiring us to run way more Rails
+application servers.
+
+## 2. CI runner long polling
+
+GitLab CI runners fetch new CI jobs by polling the GitLab server.
+Workhorse acts as a kind of "waiting room" where CI runners can sit
+and wait for new CI jobs. Because of Go's efficiency we can fit a lot
+of runners in the waiting room at little cost. Without this waiting
+room mechanism we would have to add a lot more Rails server capacity.
+
+## 3. File uploads and downloads
+
+File uploads and downloads may be slow either because the file is
+large or because the user's connection is slow. Workhorse can handle
+the slow part for Rails. This improves the efficiency of features such
+as CI artifacts, package repositories, LFS objects, etc.
+
+## 4. Websocket proxying
+
+Features such as the web terminal require a long lived connection
+between the user's web browser and a container inside GitLab that is
+not directly accessible from the internet. Dedicating a Rails
+application thread to proxying such a connection would cost much more
+memory than it costs to have Workhorse look after it.
+
+## Quick facts (how does Workhorse work)
+
+- Workhorse can handle some requests without involving Rails at all:
+  for example, JavaScript files and CSS files are served straight
+  from disk.
+- Workhorse can modify responses sent by Rails: for example if you use
+  `send_file` in Rails then GitLab Workhorse will open the file on
+  disk and send its contents as the response body to the client.
+- Workhorse can take over requests after asking permission from Rails.
+  Example: handling `git clone`.
+- Workhorse can modify requests before passing them to Rails. Example:
+  when handling a Git LFS upload Workhorse first asks permission from
+  Rails, then it stores the request body in a tempfile, then it sends
+  a modified request containing the tempfile path to Rails.
+- Workhorse can manage long-lived WebSocket connections for Rails.
+  Example: handling the terminal websocket for environments.
+- Workhorse does not connect to PostgreSQL, only to Rails and (optionally) Redis.
+- We assume that all requests that reach Workhorse pass through an
+  upstream proxy such as NGINX or Apache first.
+- Workhorse does not accept HTTPS connections.
+- Workhorse does not clean up idle client connections.
+- We assume that all requests to Rails pass through Workhorse.
+
+For more information see ['A brief history of GitLab Workhorse'][brief-history-blog].
+
+[thanos]: https://thanos-query.ops.gitlab.net/graph?g0.range_input=1h&g0.max_source_resolution=0s&g0.expr=sum(ruby_process_resident_memory_bytes%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)%20%2F%20sum(puma_max_threads%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)&g0.tab=1&g1.range_input=1h&g1.max_source_resolution=0s&g1.expr=sum(go_memstats_sys_bytes%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)%2Fsum(go_goroutines%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)&g1.tab=1
+[brief-history-blog]: https://about.gitlab.com/2016/04/12/a-brief-history-of-gitlab-workhorse/

workhorse/doc/channel.md

+This file was moved to [`architecture/channel.md`](doc/architecture/channel.md).

workhorse/doc/development/new_features.md

+## Adding new features to Workhorse
+
+GitLab Workhorse is a smart reverse proxy for GitLab. It handles
+"long" HTTP requests such as file downloads, file uploads, Git
+push/pull and Git archive downloads.
+
+Workhorse itself is not a feature, but there are [several features in GitLab](https://gitlab.com/gitlab-org/gitlab-workhorse/-/blob/master/doc/architecture/gitlab_features.md) that would not work efficiently without Workhorse.
+
+At a first glance, it may look like Workhorse is just a pipeline for processing HTTP streams so that you can reduce the amount of logic in your Ruby on Rails controller, but there are good reasons to avoid treating it like that.
+
+Engineers embarking on the quest of offloading a feature to Workhorse often find that the endeavor is much higher than what originally anticipated. In part because of the new programming language (only a few engineers at GitLab are Go developers), in part because of the demanding requirements for Workhorse. Workhorse is stateless, memory and disk usage must be kept under tight control, and the request should not be slowed down in the process.
+
+## Can I add a new feature to Workhorse?
+
+We suggest to follow this route only if absolutely necessary and no other options are available.
+
+Splitting a feature between the Rails code-base and Workhorse is deliberately choosing to introduce technical debt. It adds complexity to the system and coupling between the two components.
+
+* Building features using Workhorse has a considerable complexity cost, so you should prefer designs based on Rails requests and Sidekiq jobs.
+* Even when using Rails+Sidekiq is "more work" than using Rails+Workhorse, Rails+Sidekiq is easier to maintain in the long term because Workhorse is unique to GitLab while Rails+Sidekiq is an industry standard.
+* For "global" behaviors around web requests consider using a Rack middleware instead of Workhorse.
+* Generally speaking, we should only use Rails+Workhorse if the HTTP client expects behavior that is not reasonable to implement in Rails, like "long" requests.
+
+## What is a "long" request?
+
+There is one order of magnitude between Workhorse and puma RAM usage. Having connection open for a period longer than milliseconds is a problem because of the amount of RAM it monopolizes once it reaches the Ruby on Rails controller.
+
+So far we identified two classes of "long" requests: data transfers and HTTP long polling.
+
+`git push`, `git pull`, uploading or downloading an artifact, the CI runner waiting for a new job are all good examples of long requests.
+
+With the rise of cloud-native installations, Workhorse's feature-set was extended to add object storage direct-upload, to get rid of the shared Network File System (NFS) drives.
+
+In 2020 @nolith presented at FOSDEM a talk titled [_Speed up the monolith. Building a smart reverse proxy in Go_](https://archive.fosdem.org/2020/schedule/event/speedupmonolith/).
+You can watch the recording for more details on the history of Workhorse and the NFS removal.
+
+[Uploads development documentation]( https://docs.gitlab.com/ee/development/uploads.html)
+contains the most common use-cases for adding a new type of upload and may answer all of your questions.
+
+If you still think we should add a new feature to Workhorse, please open an issue explaining **what you want to implement** and **why it can't be implemented in our ruby code-base**. Workhorse maintainers will be happy to help you assessing the situation.
+

workhorse/doc/development/tests.md

+# Testing your code
+
+Run the tests with:
+
+```
+make clean test
+```
+
+## Coverage / what to test
+
+Each feature in GitLab Workhorse should have an integration test that
+verifies that the feature 'kicks in' on the right requests and leaves
+other requests unaffected. It is better to also have package-level tests
+for specific behavior but the high-level integration tests should have
+the first priority during development.
+
+It is OK if a feature is only covered by integration tests.

workhorse/doc/operations/configuration.md

+# Workhorse configuration
+
+For historical reasons Workhorse uses both command line flags, a configuration file and environment variables.
+
+All new configuration options that get added to Workhorse should go into the configuration file.
+
+## CLI options
+
+```
+  gitlab-workhorse [OPTIONS]
+
+Options:
+  -apiCiLongPollingDuration duration
+      Long polling duration for job requesting for runners (default 50s - enabled) (default 50ns)
+  -apiLimit uint
+      Number of API requests allowed at single time
+  -apiQueueDuration duration
+      Maximum queueing duration of requests (default 30s)
+  -apiQueueLimit uint
+      Number of API requests allowed to be queued
+  -authBackend string
+      Authentication/authorization backend (default "http://localhost:8080")
+  -authSocket string
+      Optional: Unix domain socket to dial authBackend at
+  -cableBackend string
+      Optional: ActionCable backend (default authBackend)
+  -cableSocket string
+      Optional: Unix domain socket to dial cableBackend at (default authSocket)
+  -config string
+      TOML file to load config from
+  -developmentMode
+      Allow the assets to be served from Rails app
+  -documentRoot string
+      Path to static files content (default "public")
+  -listenAddr string
+      Listen address for HTTP server (default "localhost:8181")
+  -listenNetwork string
+      Listen 'network' (tcp, tcp4, tcp6, unix) (default "tcp")
+  -listenUmask int
+      Umask for Unix socket
+  -logFile string
+      Log file location
+  -logFormat string
+      Log format to use defaults to text (text, json, structured, none) (default "text")
+  -pprofListenAddr string
+      pprof listening address, e.g. 'localhost:6060'
+  -prometheusListenAddr string
+      Prometheus listening address, e.g. 'localhost:9229'
+  -proxyHeadersTimeout duration
+      How long to wait for response headers when proxying the request (default 5m0s)
+  -secretPath string
+      File with secret key to authenticate with authBackend (default "./.gitlab_workhorse_secret")
+  -version
+      Print version and exit
+```
+
+The 'auth backend' refers to the GitLab Rails application. The name is
+a holdover from when GitLab Workhorse only handled Git push/pull over
+HTTP.
+
+GitLab Workhorse can listen on either a TCP or a Unix domain socket. It
+can also open a second listening TCP listening socket with the Go
+[net/http/pprof profiler server](http://golang.org/pkg/net/http/pprof/).
+
+GitLab Workhorse can listen on redis events (currently only builds/register
+for runners). This requires you to pass a valid TOML config file via
+`-config` flag.
+For regular setups it only requires the following (replacing the string
+with the actual socket)
+
+## Redis
+
+GitLab Workhorse integrates with Redis to do long polling for CI build
+requests. This is configured via two things:
+
+-   Redis settings in the TOML config file
+-   The `-apiCiLongPollingDuration` command line flag to control polling
+    behavior for CI build requests
+
+It is OK to enable Redis in the config file but to leave CI polling
+disabled; this just results in an idle Redis pubsub connection. The
+opposite is not possible: CI long polling requires a correct Redis
+configuration.
+
+Below we discuss the options for the `[redis]` section in the config
+file.
+
+```
+[redis]
+URL = "unix:///var/run/gitlab/redis.sock"
+Password = "my_awesome_password"
+Sentinel = [ "tcp://sentinel1:23456", "tcp://sentinel2:23456" ]
+SentinelMaster = "mymaster"
+```
+
+- `URL` takes a string in the format `unix://path/to/redis.sock` or
+`tcp://host:port`.
+- `Password` is only required if your redis instance is password-protected
+- `Sentinel` is used if you are using Sentinel.
+  *NOTE* that if both `Sentinel` and `URL` are given, only `Sentinel` will be used
+
+Optional fields are as follows:
+```
+[redis]
+DB = 0
+ReadTimeout = "1s"
+KeepAlivePeriod = "5m"
+MaxIdle = 1
+MaxActive = 1
+```
+
+- `DB` is the Database to connect to. Defaults to `0`
+- `ReadTimeout` is how long a redis read-command can take. Defaults to `1s`
+- `KeepAlivePeriod` is how long the redis connection is to be kept alive without anything flowing through it. Defaults to `5m`
+- `MaxIdle` is how many idle connections can be in the redis-pool at once. Defaults to 1
+- `MaxActive` is how many connections the pool can keep. Defaults to 1
+
+## Relative URL support
+
+If you are mounting GitLab at a relative URL, e.g.
+`example.com/gitlab`, then you should also use this relative URL in
+the `authBackend` setting:
+
+```
+gitlab-workhorse -authBackend http://localhost:8080/gitlab
+```
+
+## Interaction of authBackend and authSocket
+
+The interaction between `authBackend` and `authSocket` can be a bit
+confusing. It comes down to: if `authSocket` is set it overrides the
+_host_ part of `authBackend` but not the relative path.
+
+In table form:
+
+|authBackend|authSocket|Workhorse connects to?|Rails relative URL|
+|---|---|---|---|
+|unset|unset|`localhost:8080`|`/`|
+|`http://localhost:3000`|unset|`localhost:3000`|`/`|
+|`http://localhost:3000/gitlab`|unset|`localhost:3000`|`/gitlab`|
+|unset|`/path/to/socket`|`/path/to/socket`|`/`|
+|`http://localhost:3000`|`/path/to/socket`|`/path/to/socket`|`/`|
+|`http://localhost:3000/gitlab`|`/path/to/socket`|`/path/to/socket`|`/gitlab`|
+
+The same applies to `cableBackend` and `cableSocket`.
+
+## Error tracking
+
+GitLab-Workhorse supports remote error tracking with
+[Sentry](https://sentry.io). To enable this feature set the
+`GITLAB_WORKHORSE_SENTRY_DSN` environment variable.
+You can also set the `GITLAB_WORKHORSE_SENTRY_ENVIRONMENT` environment variable to
+use the Sentry environment functionality to separate staging, production and
+development.
+
+Omnibus (`/etc/gitlab/gitlab.rb`):
+
+```
+gitlab_workhorse['env'] = {
+    'GITLAB_WORKHORSE_SENTRY_DSN' => 'https://foobar'
+    'GITLAB_WORKHORSE_SENTRY_ENVIRONMENT' => 'production'
+}
+```
+
+Source installations (`/etc/default/gitlab`):
+
+```
+export GITLAB_WORKHORSE_SENTRY_DSN='https://foobar'
+export GITLAB_WORKHORSE_SENTRY_ENVIRONMENT='production'
+```
+
+## Distributed Tracing
+
+Workhorse supports distributed tracing through [LabKit][] using [OpenTracing APIs](https://opentracing.io).
+
+By default, no tracing implementation is linked into the binary, but different OpenTracing providers can be linked in using [build tags][build-tags]/[build constraints][build-tags]. This can be done by setting the `BUILD_TAGS` make variable.
+
+For more details of the supported providers, see LabKit, but as an example, for Jaeger tracing support, include the tags: `BUILD_TAGS="tracer_static tracer_static_jaeger"`.
+
+```shell
+make BUILD_TAGS="tracer_static tracer_static_jaeger"
+```
+
+Once Workhorse is compiled with an opentracing provider, the tracing configuration is configured via the `GITLAB_TRACING` environment variable.
+
+For example:
+
+```shell
+GITLAB_TRACING=opentracing://jaeger ./gitlab-workhorse
+```
+
+## Continuous Profiling
+
+Workhorse supports continuous profiling through [LabKit][] using [Stackdriver Profiler](https://cloud.google.com/profiler).
+
+By default, the Stackdriver Profiler implementation is linked in the binary using [build tags][build-tags], though it's not
+required and can be skipped.
+
+For example:
+
+```shell
+make BUILD_TAGS=""
+```
+
+Once Workhorse is compiled with Continuous Profiling, the profiler configuration can be set via `GITLAB_CONTINUOUS_PROFILING`
+environment variable.
+
+For example:
+
+```shell
+GITLAB_CONTINUOUS_PROFILING="stackdriver?service=workhorse&service_version=1.0.1&project_id=test-123 ./gitlab-workhorse"
+```
+
+More information about see the [LabKit monitoring docs](https://gitlab.com/gitlab-org/labkit/-/blob/master/monitoring/doc.go).
+
+[LabKit]: https://gitlab.com/gitlab-org/labkit/
+[build-tags]: https://golang.org/pkg/go/build/#hdr-Build_Constraints

workhorse/doc/operations/install.md

+# Installation
+
+To install GitLab Workhorse you need [Go 1.13 or
+newer](https://golang.org/dl) and [GNU
+Make](https://www.gnu.org/software/make/).
+
+To install into `/usr/local/bin` run `make install`.
+
+```
+make install
+```
+
+To install into `/foo/bin` set the PREFIX variable.
+
+```
+make install PREFIX=/foo
+```
+
+On some operating systems, such as FreeBSD, you may have to use
+`gmake` instead of `make`.
+
+*NOTE*: Some features depends on build tags, make sure to check
+[Workhorse configuration](doc/operations/configuration.md) to enable them.
+
+## Run time dependencies
+
+### Exiftool
+
+Workhorse uses [exiftool](https://www.sno.phy.queensu.ca/~phil/exiftool/) for
+removing EXIF data (which may contain sensitive information) from uploaded
+images. If you installed GitLab:
+
+-   Using the Omnibus package, you're all set.
+    *NOTE* that if you are using CentOS Minimal, you may need to install `perl`
+    package: `yum install perl`
+-   From source, make sure `exiftool` is installed:
+
+    ```sh
+    # Debian/Ubuntu
+    sudo apt-get install libimage-exiftool-perl
+
+    # RHEL/CentOS
+    sudo yum install perl-Image-ExifTool
+    ```

workhorse/go.mod

+module gitlab.com/gitlab-org/gitlab-workhorse
+
+go 1.13
+
+require (
+	github.com/Azure/azure-storage-blob-go v0.10.0
+	github.com/BurntSushi/toml v0.3.1
+	github.com/FZambia/sentinel v1.0.0
+	github.com/alecthomas/chroma v0.7.3
+	github.com/aws/aws-sdk-go v1.31.13
+	github.com/certifi/gocertifi v0.0.0-20200922220541-2c3bb06c6054 // indirect
+	github.com/dgrijalva/jwt-go v3.2.0+incompatible
+	github.com/disintegration/imaging v1.6.2
+	github.com/getsentry/raven-go v0.2.0
+	github.com/golang/gddo v0.0.0-20190419222130-af0f2af80721
+	github.com/golang/protobuf v1.4.2
+	github.com/gomodule/redigo v2.0.0+incompatible
+	github.com/gorilla/websocket v1.4.0
+	github.com/grpc-ecosystem/go-grpc-middleware v1.0.0
+	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0
+	github.com/johannesboyne/gofakes3 v0.0.0-20200510090907-02d71f533bec
+	github.com/jpillora/backoff v0.0.0-20170918002102-8eab2debe79d
+	github.com/mitchellh/copystructure v1.0.0
+	github.com/prometheus/client_golang v1.0.0
+	github.com/rafaeljusto/redigomock v0.0.0-20190202135759-257e089e14a1
+	github.com/sebest/xff v0.0.0-20160910043805-6c115e0ffa35
+	github.com/shabbyrobe/gocovmerge v0.0.0-20190829150210-3e036491d500 // indirect
+	github.com/sirupsen/logrus v1.7.0
+	github.com/smartystreets/goconvey v1.6.4
+	github.com/stretchr/testify v1.6.1
+	gitlab.com/gitlab-org/gitaly v1.74.0
+	gitlab.com/gitlab-org/labkit v1.0.0
+	gocloud.dev v0.20.0
+	golang.org/x/lint v0.0.0-20200302205851-738671d3881b
+	golang.org/x/net v0.0.0-20200602114024-627f9648deb9
+	golang.org/x/tools v0.0.0-20200608174601-1b747fd94509
+	google.golang.org/grpc v1.29.1
+	honnef.co/go/tools v0.0.1-2020.1.5
+)
+
+// go get tries to enforce semantic version compatibility via module paths.
+// We can't upgrade to Gitaly v13.x.x from v1.x.x without using a manual override.
+// See https://gitlab.com/gitlab-org/gitaly/-/issues/3177 for more details.
+replace gitlab.com/gitlab-org/gitaly => gitlab.com/gitlab-org/gitaly v1.87.1-0.20201001041716-3f5e218def93

workhorse/internal/api/block.go

+package api
+
+import (
+	"fmt"
+	"net/http"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
+)
+
+// Prevent internal API responses intended for gitlab-workhorse from
+// leaking to the end user
+func Block(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		rw := &blocker{rw: w, r: r}
+		defer rw.flush()
+		h.ServeHTTP(rw, r)
+	})
+}
+
+type blocker struct {
+	rw       http.ResponseWriter
+	r        *http.Request
+	hijacked bool
+	status   int
+}
+
+func (b *blocker) Header() http.Header {
+	return b.rw.Header()
+}
+
+func (b *blocker) Write(data []byte) (int, error) {
+	if b.status == 0 {
+		b.WriteHeader(http.StatusOK)
+	}
+	if b.hijacked {
+		return len(data), nil
+	}
+
+	return b.rw.Write(data)
+}
+
+func (b *blocker) WriteHeader(status int) {
+	if b.status != 0 {
+		return
+	}
+
+	if helper.IsContentType(ResponseContentType, b.Header().Get("Content-Type")) {
+		b.status = 500
+		b.Header().Del("Content-Length")
+		b.hijacked = true
+		helper.Fail500(b.rw, b.r, fmt.Errorf("api.blocker: forbidden content-type: %q", ResponseContentType))
+		return
+	}
+
+	b.status = status
+	b.rw.WriteHeader(b.status)
+}
+
+func (b *blocker) flush() {
+	b.WriteHeader(http.StatusOK)
+}

workhorse/internal/api/block_test.go

+package api
+
+import (
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestBlocker(t *testing.T) {
+	upstreamResponse := "hello world"
+
+	testCases := []struct {
+		desc        string
+		contentType string
+		out         string
+	}{
+		{
+			desc:        "blocked",
+			contentType: ResponseContentType,
+			out:         "Internal server error\n",
+		},
+		{
+			desc:        "pass",
+			contentType: "text/plain",
+			out:         upstreamResponse,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			r, err := http.NewRequest("GET", "/foo", nil)
+			require.NoError(t, err)
+
+			rw := httptest.NewRecorder()
+			bl := &blocker{rw: rw, r: r}
+			bl.Header().Set("Content-Type", tc.contentType)
+
+			upstreamBody := []byte(upstreamResponse)
+			n, err := bl.Write(upstreamBody)
+			require.NoError(t, err)
+			require.Equal(t, len(upstreamBody), n, "bytes written")
+
+			rw.Flush()
+
+			body := rw.Result().Body
+			data, err := ioutil.ReadAll(body)
+			require.NoError(t, err)
+			require.NoError(t, body.Close())
+
+			require.Equal(t, tc.out, string(data))
+		})
+	}
+}

workhorse/internal/api/channel_settings.go

+package api
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"net/http"
+	"net/url"
+
+	"github.com/gorilla/websocket"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
+)
+
+type ChannelSettings struct {
+	// The channel provider may require use of a particular subprotocol. If so,
+	// it must be specified here, and Workhorse must have a matching codec.
+	Subprotocols []string
+
+	// The websocket URL to connect to.
+	Url string
+
+	// Any headers (e.g., Authorization) to send with the websocket request
+	Header http.Header
+
+	// The CA roots to validate the remote endpoint with, for wss:// URLs. The
+	// system-provided CA pool will be used if this is blank. PEM-encoded data.
+	CAPem string
+
+	// The value is specified in seconds. It is converted to time.Duration
+	// later.
+	MaxSessionTime int
+}
+
+func (t *ChannelSettings) URL() (*url.URL, error) {
+	return url.Parse(t.Url)
+}
+
+func (t *ChannelSettings) Dialer() *websocket.Dialer {
+	dialer := &websocket.Dialer{
+		Subprotocols: t.Subprotocols,
+	}
+
+	if len(t.CAPem) > 0 {
+		pool := x509.NewCertPool()
+		pool.AppendCertsFromPEM([]byte(t.CAPem))
+		dialer.TLSClientConfig = &tls.Config{RootCAs: pool}
+	}
+
+	return dialer
+}
+
+func (t *ChannelSettings) Clone() *ChannelSettings {
+	// Doesn't clone the strings, but that's OK as strings are immutable in go
+	cloned := *t
+	cloned.Header = helper.HeaderClone(t.Header)
+	return &cloned
+}
+
+func (t *ChannelSettings) Dial() (*websocket.Conn, *http.Response, error) {
+	return t.Dialer().Dial(t.Url, t.Header)
+}
+
+func (t *ChannelSettings) Validate() error {
+	if t == nil {
+		return fmt.Errorf("channel details not specified")
+	}
+
+	if len(t.Subprotocols) == 0 {
+		return fmt.Errorf("no subprotocol specified")
+	}
+
+	parsedURL, err := t.URL()
+	if err != nil {
+		return fmt.Errorf("invalid URL")
+	}
+
+	if parsedURL.Scheme != "ws" && parsedURL.Scheme != "wss" {
+		return fmt.Errorf("invalid websocket scheme: %q", parsedURL.Scheme)
+	}
+
+	return nil
+}
+
+func (t *ChannelSettings) IsEqual(other *ChannelSettings) bool {
+	if t == nil && other == nil {
+		return true
+	}
+
+	if t == nil || other == nil {
+		return false
+	}
+
+	if len(t.Subprotocols) != len(other.Subprotocols) {
+		return false
+	}
+
+	for i, subprotocol := range t.Subprotocols {
+		if other.Subprotocols[i] != subprotocol {
+			return false
+		}
+	}
+
+	if len(t.Header) != len(other.Header) {
+		return false
+	}
+
+	for header, values := range t.Header {
+		if len(values) != len(other.Header[header]) {
+			return false
+		}
+		for i, value := range values {
+			if other.Header[header][i] != value {
+				return false
+			}
+		}
+	}
+
+	return t.Url == other.Url &&
+		t.CAPem == other.CAPem &&
+		t.MaxSessionTime == other.MaxSessionTime
+}

workhorse/internal/git/error.go

+package git
+
+// For cosmetic purposes in Sentry
+type copyError struct{ error }