Implement Go module proxy pseudo-versions

ee/app/models/packages/go_module.rb

 # frozen_string_literal: true
 
 class Packages::GoModule
-  SEMVER_TAG_REGEX = /^v(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-([-.a-z0-9]+))?(?:\+([-.a-z0-9]+))?$/i.freeze
-
-  # belongs_to :project
-
   attr_reader :project, :name, :path
 
   def initialize(project, name)
@@ -23,13 +19,21 @@ class Packages::GoModule
 
   def versions
     @versions ||= @project.repository.tags
-      .filter { |tag| SEMVER_TAG_REGEX.match?(tag.name) && !tag.dereferenced_target.nil? }
+      .filter { |tag| ::Packages::GoModuleVersion.semver? tag }
       .map    { |tag| ::Packages::GoModuleVersion.new self, tag }
       .filter { |ver| ver.valid? }
   end
 
   def find_version(name)
-    versions.filter { |ver| ver.name == name }.first
+    if ::Packages::GoModuleVersion.pseudo_version? name
+      begin
+        ::Packages::GoModuleVersion.new self, name
+      rescue ArgumentError
+        nil
+      end
+    else
+      versions.filter { |ver| ver.name == name }.first
+    end
   end
 
   private

ee/app/models/packages/go_module_version.rb

@@ -2,21 +2,77 @@
 
 class Packages::GoModuleVersion
   SEMVER_REGEX = /v(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-([-.a-z0-9]+))?(?:\+([-.a-z0-9]+))?/i.freeze
+  SEMVER_TAG_REGEX = /^v(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-([-.a-z0-9]+))?(?:\+([-.a-z0-9]+))?$/i.freeze
+  PSEUDO_VERSION_REGEX = /^v\d+\.(0\.0-|\d+\.\d+-([^+]*\.)?0\.)\d{14}-[A-Za-z0-9]+(\+[0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*)?$/i.freeze
   VERSION_SUFFIX_REGEX = /\/v([1-9]\d*)$/i.freeze
 
-  # belongs_to :mod
+  attr_reader :mod, :type, :ref, :commit
 
-  attr_reader :mod, :tag
+  delegate :major, to: :@semver, allow_nil: true
+  delegate :minor, to: :@semver, allow_nil: true
+  delegate :patch, to: :@semver, allow_nil: true
+  delegate :prerelease, to: :@semver, allow_nil: true
+  delegate :build, to: :@semver, allow_nil: true
 
-  delegate :name, to: :tag
+  def self.semver?(tag)
+    return false if tag.dereferenced_target.nil?
 
-  def initialize(mod, tag)
+    SEMVER_TAG_REGEX.match?(tag.name)
+  end
+
+  def self.pseudo_version?(str)
+    SEMVER_TAG_REGEX.match?(str) && PSEUDO_VERSION_REGEX.match?(str)
+  end
+
+  def initialize(mod, target)
     @mod = mod
-    @tag = tag
+
+    case target
+    when String
+      m = SEMVER_TAG_REGEX.match(target)
+      raise ArgumentError.new 'target is not a pseudo-version' unless m && PSEUDO_VERSION_REGEX.match?(target)
+
+      # valid pseudo-versions are
+      #   vX.0.0-yyyymmddhhmmss-sha1337beef0, when no earlier tagged commit exists for X
+      #   vX.Y.Z-pre.0.yyyymmddhhmmss-sha1337beef0, when most recent prior tag is vX.Y.Z-pre
+      #   vX.Y.(Z+1)-0.yyyymmddhhmmss-sha1337beef0, when most recent prior tag is vX.Y.Z
+
+      # go discards the timestamp when resolving pseudo-versions, so we will do the same
+
+      @type = :pseudo
+      @name = target
+      @semver = semver_match_to_hash m
+
+      timestamp, sha = prerelease.split('-').last 2
+      timestamp = timestamp.split('.').last
+      @commit = mod.project.repository.commit_by(oid: sha)
+
+      # these errors are copied from proxy.golang.org's responses
+      raise ArgumentError.new 'invalid pseudo-version: unknown commit' unless @commit
+      raise ArgumentError.new 'invalid pseudo-version: revision is shorter than canonical' unless sha.length == 12
+      raise ArgumentError.new 'invalid pseudo-version: does not match version-control timestamp' unless @commit.committed_date.strftime('%Y%m%d%H%M%S') == timestamp
+
+    when Gitlab::Git::Ref
+      @type = :ref
+      @ref = target
+      @commit = target.dereferenced_target
+      @semver = semver_match_to_hash SEMVER_TAG_REGEX.match(target.name)
+
+    when ::Commit, Gitlab::Git::Commit
+      @type = :commit
+      @commit = target
+
+    else
+      raise ArgumentError.new 'not a valid target'
+    end
+  end
+
+  def name
+    @name || @ref&.name
   end
 
   def gomod
-    @gomod ||= @mod.project.repository.blob_at(@tag.dereferenced_target.sha, @mod.path + '/go.mod')&.data
+    @gomod ||= @mod.project.repository.blob_at(@commit.sha, @mod.path + '/go.mod')&.data
   end
 
   def valid?
@@ -40,36 +96,33 @@ class Packages::GoModuleVersion
     gomod.split("\n", 2).first == "module #{@mod.name}"
   end
 
-  def major
-    SEMVER_REGEX.match(@tag.name)[1].to_i
-  end
-
-  def minor
-    SEMVER_REGEX.match(@tag.name)[2].to_i
-  end
-
-  def patch
-    SEMVER_REGEX.match(@tag.name)[3].to_i
-  end
-
-  def prerelease
-    SEMVER_REGEX.match(@tag.name)[4]
-  end
-
-  def build
-    SEMVER_REGEX.match(@tag.name)[5]
+  def pseudo?
+    @type == :pseudo
   end
 
   def files
     return @files unless @files.nil?
 
-    sha = @tag.dereferenced_target.sha
+    sha = @commit.sha
     tree = @mod.project.repository.tree(sha, @mod.path, recursive: true).entries.filter { |e| e.file? }
     nested = tree.filter { |e| e.name == 'go.mod' && !(@mod.path == '' && e.path == 'go.mod' || e.path == @mod.path + '/go.mod') }.map { |e| e.path[0..-7] }
     @files = tree.filter { |e| !nested.any? { |n| e.path.start_with? n } }
   end
 
   def blob_at(path)
-    @mod.project.repository.blob_at(tag.dereferenced_target.sha, path).data
+    @mod.project.repository.blob_at(@commit.sha, path).data
+  end
+
+  private
+
+  def semver_match_to_hash(match)
+    return unless match
+
+    OpenStruct.new(
+      major: match[1].to_i,
+      minor: match[2].to_i,
+      patch: match[3].to_i,
+      prerelease: match[4],
+      build: match[5])
   end
 end

ee/app/presenters/packages/go/module_version_presenter.rb

@@ -12,7 +12,7 @@ module Packages
       end
 
       def time
-        @version.tag.dereferenced_target.committed_date
+        @version.commit.committed_date
       end
     end
   end

ee/lib/api/go_proxy.rb

@@ -28,7 +28,7 @@ module API
         mod = find_module
 
         ver = mod.find_version case_decode params[:module_version]
-        not_found! unless ver
+        not_found! unless ver&.valid?
 
         ver
       end

ee/spec/requests/api/go_proxy_spec.rb

@@ -23,11 +23,11 @@ describe API::GoProxy do
     create_version(1, 0, 1, create_module)
     create_version(1, 0, 2, create_package('pkg'))
     create_version(1, 0, 3, create_module('mod'))
-                            create_module('v2')
+    sha1 =                  create_file('y.go', "package a\n")
+    sha2 =                  create_module('v2')
     create_version(2, 0, 0, create_file('v2/x.go', "package a\n"))
-                            create_file('v2/y.go', "package a\n") # todo tag this v1.0.4
 
-    project.repository.head_commit
+    { sha: [sha1, sha2] }
   end
 
   context 'with an invalid module directive' do
@@ -73,7 +73,7 @@ describe API::GoProxy do
         let(:module_name) { base }
         let(:resource) { "v1.0.0.info" }
 
-        it 'returns 404' do
+        it 'returns not found' do
           get_resource(user)
 
           expect(response).to have_gitlab_http_status(:not_found)
@@ -84,7 +84,7 @@ describe API::GoProxy do
         let(:module_name) { "#{base}/v2" }
         let(:resource) { "v2.0.0.info" }
 
-        it 'returns 404' do
+        it 'returns not found' do
           get_resource(user)
 
           expect(response).to have_gitlab_http_status(:not_found)
@@ -122,7 +122,7 @@ describe API::GoProxy do
       context 'without a case encoded path' do
         let(:module_name) { base.downcase }
 
-        it 'returns 404' do
+        it 'returns not found' do
           get_resource(user)
 
           expect(response).to have_gitlab_http_status(:not_found)
@@ -212,44 +212,46 @@ describe API::GoProxy do
   end
 
   describe 'GET /projects/:id/packages/go/*module_name/@v/:module_version.info' do
+    let(:resource) { "#{version}.info" }
+
     context 'with the root module v1.0.1' do
       let(:module_name) { base }
-      let(:resource) { "v1.0.1.info" }
+      let(:version) { "v1.0.1" }
 
       it 'returns correct information' do
         get_resource(user)
 
-        expect_module_version_info('v1.0.1')
+        expect_module_version_info(version)
       end
     end
 
     context 'with the submodule v1.0.3' do
       let(:module_name) { "#{base}/mod" }
-      let(:resource) { "v1.0.3.info" }
+      let(:version) { "v1.0.3" }
 
       it 'returns correct information' do
         get_resource(user)
 
-        expect_module_version_info('v1.0.3')
+        expect_module_version_info(version)
       end
     end
 
     context 'with the root module v2.0.0' do
       let(:module_name) { "#{base}/v2" }
-      let(:resource) { "v2.0.0.info" }
+      let(:version) { "v2.0.0" }
 
       it 'returns correct information' do
         get_resource(user)
 
-        expect_module_version_info('v2.0.0')
+        expect_module_version_info(version)
       end
     end
 
     context 'with an invalid path' do
       let(:module_name) { "#{base}/pkg" }
-      let(:resource) { "v1.0.3.info" }
+      let(:version) { "v1.0.3" }
 
-      it 'returns 404' do
+      it 'returns not found' do
         get_resource(user)
 
         expect(response).to have_gitlab_http_status(:not_found)
@@ -258,9 +260,75 @@ describe API::GoProxy do
 
     context 'with an invalid version' do
       let(:module_name) { "#{base}/mod" }
-      let(:resource) { "v1.0.1.info" }
+      let(:version) { "v1.0.1" }
 
-      it 'returns 404' do
+      it 'returns not found' do
+        get_resource(user)
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
+    end
+
+    context 'with a pseudo-version for v1' do
+      let(:module_name) { base }
+      let(:commit) { project.repository.commit_by(oid: modules[:sha][0]) }
+      let(:version) { "v1.0.4-0.#{commit.committed_date.strftime('%Y%m%d%H%M%S')}-#{commit.sha[0..11]}" }
+
+      it 'returns the correct commit' do
+        get_resource(user)
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(json_response).to be_kind_of(Hash)
+        expect(json_response['Version']).to eq(version)
+        expect(json_response['Time']).to eq(commit.committed_date.strftime '%Y-%m-%dT%H:%M:%S.%L%:z')
+      end
+    end
+
+    context 'with a pseudo-version for v2' do
+      let(:module_name) { "#{base}/v2" }
+      let(:commit) { project.repository.commit_by(oid: modules[:sha][1]) }
+      let(:version) { "v2.0.0-#{commit.committed_date.strftime('%Y%m%d%H%M%S')}-#{commit.sha[0..11]}" }
+
+      it 'returns the correct commit' do
+        get_resource(user)
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(json_response).to be_kind_of(Hash)
+        expect(json_response['Version']).to eq(version)
+        expect(json_response['Time']).to eq(commit.committed_date.strftime '%Y-%m-%dT%H:%M:%S.%L%:z')
+      end
+    end
+
+    context 'with a pseudo-version with an invalid timestamp' do
+      let(:module_name) { base }
+      let(:commit) { project.repository.commit_by(oid: modules[:sha][0]) }
+      let(:version) { "v1.0.4-0.00000000000000-#{commit.sha[0..11]}" }
+
+      it 'returns not found' do
+        get_resource(user)
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
+    end
+
+    context 'with a pseudo-version with an invalid commit sha' do
+      let(:module_name) { base }
+      let(:commit) { project.repository.commit_by(oid: modules[:sha][0]) }
+      let(:version) { "v1.0.4-0.#{commit.committed_date.strftime('%Y%m%d%H%M%S')}-000000000000" }
+
+      it 'returns not found' do
+        get_resource(user)
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
+    end
+
+    context 'with a pseudo-version with a short commit sha' do
+      let(:module_name) { base }
+      let(:commit) { project.repository.commit_by(oid: modules[:sha][0]) }
+      let(:version) { "v1.0.4-0.#{commit.committed_date.strftime('%Y%m%d%H%M%S')}-#{commit.sha[0..10]}" }
+
+      it 'returns not found' do
         get_resource(user)
 
         expect(response).to have_gitlab_http_status(:not_found)
@@ -269,9 +337,11 @@ describe API::GoProxy do
   end
 
   describe 'GET /projects/:id/packages/go/*module_name/@v/:module_version.mod' do
+    let(:resource) { "#{version}.mod" }
+
     context 'with the root module v1.0.1' do
       let(:module_name) { base }
-      let(:resource) { "v1.0.1.mod" }
+      let(:version) { "v1.0.1" }
 
       it 'returns correct content' do
         get_resource(user)
@@ -282,7 +352,7 @@ describe API::GoProxy do
 
     context 'with the submodule v1.0.3' do
       let(:module_name) { "#{base}/mod" }
-      let(:resource) { "v1.0.3.mod" }
+      let(:version) { "v1.0.3" }
 
       it 'returns correct content' do
         get_resource(user)
@@ -293,7 +363,7 @@ describe API::GoProxy do
 
     context 'with the root module v2.0.0' do
       let(:module_name) { "#{base}/v2" }
-      let(:resource) { "v2.0.0.mod" }
+      let(:version) { "v2.0.0" }
 
       it 'returns correct content' do
         get_resource(user)
@@ -304,9 +374,9 @@ describe API::GoProxy do
 
     context 'with an invalid path' do
       let(:module_name) { "#{base}/pkg" }
-      let(:resource) { "v1.0.3.mod" }
+      let(:version) { "v1.0.3" }
 
-      it 'returns 404' do
+      it 'returns not found' do
         get_resource(user)
 
         expect(response).to have_gitlab_http_status(:not_found)
@@ -315,9 +385,9 @@ describe API::GoProxy do
 
     context 'with an invalid version' do
       let(:module_name) { "#{base}/mod" }
-      let(:resource) { "v1.0.1.mod" }
+      let(:version) { "v1.0.1" }
 
-      it 'returns 404' do
+      it 'returns not found' do
         get_resource(user)
 
         expect(response).to have_gitlab_http_status(:not_found)
@@ -326,58 +396,60 @@ describe API::GoProxy do
   end
 
   describe 'GET /projects/:id/packages/go/*module_name/@v/:module_version.zip' do
+    let(:resource) { "#{version}.zip" }
+
     context 'with the root module v1.0.1' do
       let(:module_name) { base }
-      let(:resource) { "v1.0.1.zip" }
+      let(:version) { "v1.0.1" }
 
       it 'returns a zip of everything' do
         get_resource(user)
 
-        expect_module_version_zip(module_name, 'v1.0.1', ['README.md', 'go.mod', 'a.go'])
+        expect_module_version_zip(module_name, version, ['README.md', 'go.mod', 'a.go'])
       end
     end
 
     context 'with the root module v1.0.2' do
       let(:module_name) { base }
-      let(:resource) { "v1.0.2.zip" }
+      let(:version) { "v1.0.2" }
 
       it 'returns a zip of everything' do
         get_resource(user)
 
-        expect_module_version_zip(module_name, 'v1.0.2', ['README.md', 'go.mod', 'a.go', 'pkg/b.go'])
+        expect_module_version_zip(module_name, version, ['README.md', 'go.mod', 'a.go', 'pkg/b.go'])
       end
     end
 
     context 'with the root module v1.0.3' do
       let(:module_name) { base }
-      let(:resource) { "v1.0.3.zip" }
+      let(:version) { "v1.0.3" }
 
       it 'returns a zip of everything, excluding the submodule' do
         get_resource(user)
 
-        expect_module_version_zip(module_name, 'v1.0.3', ['README.md', 'go.mod', 'a.go', 'pkg/b.go'])
+        expect_module_version_zip(module_name, version, ['README.md', 'go.mod', 'a.go', 'pkg/b.go'])
       end
     end
 
     context 'with the submodule v1.0.3' do
       let(:module_name) { "#{base}/mod" }
-      let(:resource) { "v1.0.3.zip" }
+      let(:version) { "v1.0.3" }
 
       it 'returns a zip of the submodule' do
         get_resource(user)
 
-        expect_module_version_zip(module_name, 'v1.0.3', ['go.mod', 'a.go'])
+        expect_module_version_zip(module_name, version, ['go.mod', 'a.go'])
       end
     end
 
     context 'with the root module v2.0.0' do
       let(:module_name) { "#{base}/v2" }
-      let(:resource) { "v2.0.0.zip" }
+      let(:version) { "v2.0.0" }
 
       it 'returns a zip of v2 of the root module' do
         get_resource(user)
 
-        expect_module_version_zip(module_name, 'v2.0.0', ['go.mod', 'a.go', 'x.go'])
+        expect_module_version_zip(module_name, version, ['go.mod', 'a.go', 'x.go'])
       end
     end
   end
@@ -402,29 +474,29 @@ describe API::GoProxy do
   end
 
   shared_examples 'a module that requires auth' do
-    it 'returns 200 with oauth token' do
+    it 'returns ok with oauth token' do
       get_resource(access_token: oauth.token)
       expect(response).to have_gitlab_http_status(:ok)
     end
 
-    it 'returns 200 with job token' do
+    it 'returns ok with job token' do
       get_resource(job_token: job.token)
       expect(response).to have_gitlab_http_status(:ok)
     end
 
-    it 'returns 200 with personal access token' do
+    it 'returns ok with personal access token' do
       get_resource(personal_access_token: pa_token)
       expect(response).to have_gitlab_http_status(:ok)
     end
 
-    it 'returns 404 with no authentication' do
+    it 'returns not found with no authentication' do
       get_resource
       expect(response).to have_gitlab_http_status(:not_found)
     end
   end
 
   shared_examples 'a module that does not require auth' do
-    it 'returns 200 with no authentication' do
+    it 'returns ok with no authentication' do
       get_resource
       expect(response).to have_gitlab_http_status(:ok)
     end
@@ -499,12 +571,12 @@ describe API::GoProxy do
   end
 
   def expect_module_version_info(version)
-    # time = project.repository.find_tag(version).dereferenced_target.committed_date
+    time = project.repository.find_tag(version).dereferenced_target.committed_date
 
     expect(response).to have_gitlab_http_status(:ok)
     expect(json_response).to be_kind_of(Hash)
     expect(json_response['Version']).to eq(version)
-    # expect(Date.parse json_response['Time']).to eq(time)
+    expect(json_response['Time']).to eq(time.strftime '%Y-%m-%dT%H:%M:%S.%L%:z')
   end
 
   def expect_module_version_mod(name)