Merge branch 'custom-gitaly-url' into 'master'

Allow Gitaly to be built from a custom URL

See merge request gitlab-org/gitlab-ce!24616

doc/development/gitaly.md

@@ -130,6 +130,25 @@ Gitaly. To use a custom Gitaly version in CI you need to update
 GITALY_SERVER_VERSION. You can use the format `=revision` to use a
 non-tagged commit from https://gitlab.com/gitlab-org/gitaly in CI.
 
+To use a different Gitaly repository, e.g., if your changes are present
+on a fork, you can specify a `GITALY_REPO_URL` environment variable when
+running tests:
+
+```shell
+GITALY_REPO_URL=https://gitlab.com/nick.thomas/gitaly bundle exec rspec spec/lib/gitlab/git/repository_spec.rb
+```
+
+If your fork of Gitaly is private, you can generate a [Deploy Token](../user/project/deploy_tokens/index.md)
+and specify it in the URL:
+
+```shell
+GITALY_REPO_URL=https://gitlab+deploy-token-1000:token-here@gitlab.com/nick.thomas/gitaly bundle exec rspec spec/lib/gitlab/git/repository_spec.rb
+```
+
+To use a custom Gitaly repository in CI, for instance if you want your
+GitLab fork to always use your own Gitaly fork, set `GITALY_REPO_URL`
+as a [CI environment variable](../ci/variables/README.md#variables).
+
 ---
 
 [Return to Development documentation](README.md)

spec/support/helpers/test_env.rb

@@ -160,11 +160,12 @@ module TestEnv
   def setup_gitaly
     socket_path = Gitlab::GitalyClient.address('default').sub(/\Aunix:/, '')
     gitaly_dir = File.dirname(socket_path)
+    install_gitaly_args = [gitaly_dir, repos_path, gitaly_url].compact.join(',')
 
     component_timed_setup('Gitaly',
       install_dir: gitaly_dir,
       version: Gitlab::GitalyClient.expected_server_version,
-      task: "gitlab:gitaly:install[#{gitaly_dir},#{repos_path}]") do
+      task: "gitlab:gitaly:install[#{install_gitaly_args}]") do
 
         Gitlab::SetupHelper.create_gitaly_configuration(gitaly_dir, { 'default' => repos_path }, force: true)
         start_gitaly(gitaly_dir)
@@ -215,6 +216,10 @@ module TestEnv
     # The process can already be gone if the test run was INTerrupted.
   end
 
+  def gitaly_url
+    ENV.fetch('GITALY_REPO_URL', nil)
+  end
+
   def setup_factory_repo
     setup_repo(factory_repo_path, factory_repo_path_bare, factory_repo_name,
                BRANCH_SHA)