Merge branch 'artifacts-from-ref-and-build-name-api' into 'master'

Simpler two queries than one JOIN with subquery

This is a follow up from !5347

Originally it was:

``` ruby
pipeline = pipelines.latest_successful_for(ref)
builds.where(pipeline: pipeline).latest.with_artifacts
```

However MySQL would complain that we can't use `IN` against a subquery which has `LIMIT`. Using `INNER JOIN` would be a workaround, however, doing that is too complicated in current version of Rails.

So let's just use two queries in this case.

Closes #14419

See merge request !5388

app/models/project.rb

@@ -431,13 +431,13 @@ class Project < ActiveRecord::Base
 
   # ref can't be HEAD, can only be branch/tag name or SHA
   def latest_successful_builds_for(ref = default_branch)
-    pipeline = pipelines.latest_successful_for(ref).to_sql
-    join_sql = "INNER JOIN (#{pipeline}) pipelines" +
-               " ON pipelines.id = #{Ci::Build.quoted_table_name}.commit_id"
-    builds.joins(join_sql).latest.with_artifacts
-    # TODO: Whenever we dropped support for MySQL, we could change to:
-    # pipeline = pipelines.latest_successful_for(ref)
-    # builds.where(pipeline: pipeline).latest.with_artifacts
+    latest_pipeline = pipelines.latest_successful_for(ref).first
+
+    if latest_pipeline
+      latest_pipeline.builds.latest.with_artifacts
+    else
+      builds.none
+    end
   end
 
   def merge_base_commit(first_commit_id, second_commit_id)

doc/api/builds.md

@@ -283,6 +283,40 @@ Response:
 
 [ce-2893]: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/2893
 
+## Download the artifacts file
+
+> [Introduced][ce-5347] in GitLab 8.10.
+
+Download the artifacts file from the given reference name and job provided the
+build finished successfully.
+
+```
+GET /projects/:id/builds/artifacts/:ref_name/download?job=name
+```
+
+Parameters
+
+| Attribute   | Type    | Required | Description               |
+|-------------|---------|----------|-------------------------- |
+| `id`        | integer | yes      | The ID of a project       |
+| `ref_name`  | string  | yes      | The ref from a repository |
+| `job`       | string  | yes      | The name of the job       |
+
+Example request:
+
+```
+curl -H "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v3/projects/1/builds/artifacts/master/download?job=test"
+```
+
+Example response:
+
+| Status    | Description                     |
+|-----------|---------------------------------|
+| 200       | Serves the artifacts file       |
+| 404       | Build not found or no artifacts |
+
+[ce-5347]: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5347
+
 ## Get a trace file
 
 Get a trace of a specific build of a project
@@ -409,7 +443,7 @@ POST /projects/:id/builds/:build_id/erase
 
 Parameters
 
-| Attribute   | Type    | required | Description         |
+| Attribute   | Type    | Required | Description         |
 |-------------|---------|----------|---------------------|
 | `id`        | integer | yes      | The ID of a project |
 | `build_id`  | integer | yes      | The ID of a build   |
@@ -459,7 +493,7 @@ POST /projects/:id/builds/:build_id/artifacts/keep
 
 Parameters
 
-| Attribute   | Type    | required | Description         |
+| Attribute   | Type    | Required | Description         |
 |-------------|---------|----------|---------------------|
 | `id`        | integer | yes      | The ID of a project |
 | `build_id`  | integer | yes      | The ID of a build   |

lib/api/builds.rb

@@ -80,7 +80,7 @@ module API
       #   ref_name (required) - The ref from repository
       #   job (required) - The name for the build
       # Example Request:
-      #   GET /projects/:id/artifacts/:ref_name/download?job=name
+      #   GET /projects/:id/builds/artifacts/:ref_name/download?job=name
       get ':id/builds/artifacts/:ref_name/download',
         requirements: { ref_name: /.+/ } do
         authorize_read_builds!