Add endpoint to download single artifact by ref

Add a new endpoint
`projects/:id/jobs/artifacts/:ref_name/raw/*artifact_path?job=name`
which is the close the web URL for consistency sake. This endpoint can
be used to download a single file from artifacts for the specified ref
and job.

closes https://gitlab.com/gitlab-org/gitlab-ce/issues/54626

1 files changed, 24 insertions, 0 deletions

diff --git a/lib/api/job_artifacts.rb b/lib/api/job_artifacts.rb
index 7c2d8ff11bf..a4068a200b3 100644
--- a/lib/api/job_artifacts.rb
+++ b/lib/api/job_artifacts.rb
@@ -35,6 +35,29 @@ module API
       end
       # rubocop: enable CodeReuse/ActiveRecord
 
+      desc 'Download a specific file from artifacts archive from a ref' do
+        detail 'This feature was introduced in GitLab 11.5'
+      end
+      params do
+        requires :ref_name, type: String, desc: 'The ref from repository'
+        requires :job, type: String, desc: 'The name for the job'
+        requires :artifact_path, type: String, desc: 'Artifact path'
+      end
+      get ':id/jobs/artifacts/:ref_name/raw/*artifact_path',
+          format: false,
+          requirements: { ref_name: /.+/ } do
+        authorize_download_artifacts!
+
+        build = user_project.latest_successful_build_for(params[:job], params[:ref_name])
+
+        path = Gitlab::Ci::Build::Artifacts::Path
+                 .new(params[:artifact_path])
+
+        bad_request! unless path.valid?
+
+        send_artifacts_entry(build, path)
+      end
+
       desc 'Download the artifacts archive from a job' do
         detail 'This feature was introduced in GitLab 8.5'
       end
@@ -65,6 +88,7 @@ module API
 
         path = Gitlab::Ci::Build::Artifacts::Path
           .new(params[:artifact_path])
+
         bad_request! unless path.valid?
 
         send_artifacts_entry(build, path)