Merge branch '17521-gitlab-ci-yml-templates' into 'master'

GitLab CI Yaml template dropdown

## What does this MR do?
Make it possible to select a dropdown for an easy start with GitLab CI.

## What are the relevant issue numbers?
Closes #17521

## TODO
- [ ] Backend
  - [x] CHANGELOG item
  - [x] Fix rubocop failure
  - [x] API Support
  - [x] New tests
  - [x] Add disclaimer to the top of the gitlab-ci.yml
- [ ] Frontend
  - [x] New tests

See merge request !4411

3 files changed, 31 insertions, 0 deletions

diff --git a/app/assets/javascripts/api.js.coffee b/app/assets/javascripts/api.js.coffee
index 3f61ea1eaf4..cf46f15a156 100644
--- a/app/assets/javascripts/api.js.coffee
+++ b/app/assets/javascripts/api.js.coffee
@@ -7,6 +7,7 @@
   labelsPath: "/api/:version/projects/:id/labels"
   licensePath: "/api/:version/licenses/:key"
   gitignorePath: "/api/:version/gitignores/:key"
+  gitlabCiYmlPath: "/api/:version/gitlab_ci_ymls/:key"
 
   group: (group_id, callback) ->
     url = Api.buildUrl(Api.groupPath)
@@ -110,6 +111,12 @@
     $.get url, (gitignore) ->
       callback(gitignore)
 
+  gitlabCiYml: (key, callback) ->
+    url = Api.buildUrl(Api.gitlabCiYmlPath).replace(':key', key)
+
+    $.get url, (file) ->
+      callback(file)
+
   buildUrl: (url) ->
     url = gon.relative_url_root + url if gon.relative_url_root?
     return url.replace(':version', gon.api_version)
diff --git a/app/assets/javascripts/blob/blob_ci_yaml.js.coffee b/app/assets/javascripts/blob/blob_ci_yaml.js.coffee
new file mode 100644
index 00000000000..d9a03d05529
--- /dev/null
+++ b/app/assets/javascripts/blob/blob_ci_yaml.js.coffee
@@ -0,0 +1,23 @@
+#= require blob/template_selector
+
+class @BlobCiYamlSelector extends TemplateSelector
+  requestFile: (query) ->
+    Api.gitlabCiYml query.name, @requestFileSuccess.bind(@)
+
+class @BlobCiYamlSelectors
+  constructor: (opts) ->
+    {
+      @$dropdowns = $('.js-gitlab-ci-yml-selector')
+      @editor
+    } = opts
+
+    @$dropdowns.each (i, dropdown) =>
+      $dropdown = $(dropdown)
+
+      new BlobCiYamlSelector(
+        pattern: /(.gitlab-ci.yml)/,
+        data: $dropdown.data('data'),
+        wrapper: $dropdown.closest('.js-gitlab-ci-yml-selector-wrap'),
+        dropdown: $dropdown,
+        editor: @editor
+      )
diff --git a/app/assets/javascripts/blob/edit_blob.js.coffee b/app/assets/javascripts/blob/edit_blob.js.coffee
index 636f909dbd0..19e584519d7 100644
--- a/app/assets/javascripts/blob/edit_blob.js.coffee
+++ b/app/assets/javascripts/blob/edit_blob.js.coffee
@@ -15,6 +15,7 @@ class @EditBlob
 
     new BlobLicenseSelectors { @editor }
     new BlobGitignoreSelectors { @editor }
+    new BlobCiYamlSelectors { @editor }
 
   initModePanesAndLinks: ->
     @$editModePanes = $(".js-edit-mode-pane")