Merge branch 'cc-add-ci-merge-request-description' into 'master'

Add CI_MERGE_REQUEST_DESCRIPTION env variable

See merge request gitlab-org/gitlab!40771

app/models/merge_request.rb

@@ -1324,6 +1324,7 @@ class MergeRequest < ApplicationRecord
       variables.append(key: 'CI_MERGE_REQUEST_PROJECT_URL', value: project.web_url)
       variables.append(key: 'CI_MERGE_REQUEST_TARGET_BRANCH_NAME', value: target_branch.to_s)
       variables.append(key: 'CI_MERGE_REQUEST_TITLE', value: title)
+      variables.append(key: 'CI_MERGE_REQUEST_DESCRIPTION', value: description) if Gitlab::Ci::Features.expose_mr_description_predefined_variable?
       variables.append(key: 'CI_MERGE_REQUEST_ASSIGNEES', value: assignee_username_list) if assignees.present?
       variables.append(key: 'CI_MERGE_REQUEST_MILESTONE', value: milestone.title) if milestone
       variables.append(key: 'CI_MERGE_REQUEST_LABELS', value: label_names.join(',')) if labels.present?

changelogs/unreleased/CI_MERGE_REQUEST_DESCRIPTION.yml

+---
+title: Add CI_MERGE_REQUEST_DESCRIPTION env variable
+merge_request: 40771
+author: Paul Spooren @aparcar
+type: added

config/feature_flags/development/expose_mr_description_predefined_variable.yml

+---
+name: expose_mr_description_predefined_variable
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/40771
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/243556
+group: group::continuous integration
+type: development
+default_enabled: true

doc/ci/variables/predefined_variables.md

@@ -89,6 +89,7 @@ Kubernetes-specific environment variables are detailed in the
 | `CI_MERGE_REQUEST_TARGET_BRANCH_NAME`         | 11.6   | all    | The target branch name of the merge request if [the pipelines are for merge requests](../merge_request_pipelines/index.md). Available only if `only: [merge_requests]` or [`rules`](../yaml/README.md#rules) syntax is used and the merge request is created.                                                                                                                                           |
 | `CI_MERGE_REQUEST_TARGET_BRANCH_SHA`          | 11.9   | all    | The HEAD SHA of the target branch of the merge request if [the pipelines are for merge requests](../merge_request_pipelines/index.md). Available only if `only: [merge_requests]` or [`rules`](../yaml/README.md#rules) syntax is used, the merge request is created, and the pipeline is a [merged result pipeline](../merge_request_pipelines/pipelines_for_merged_results/index.md). **(PREMIUM)**   |
 | `CI_MERGE_REQUEST_TITLE`                      | 11.9   | all    | The title of the merge request if [the pipelines are for merge requests](../merge_request_pipelines/index.md). Available only if `only: [merge_requests]` or [`rules`](../yaml/README.md#rules) syntax is used and the merge request is created.                                                                                                                                                        |
+| `CI_MERGE_REQUEST_DESCRIPTION`                | 13.3   | all    | The description of the merge request if [the pipelines are for merge requests](../merge_request_pipelines/index.md). Available only if `only: [merge_requests]` or [`rules`](../yaml/README.md#rules) syntax is used and the merge request is created.                                                                                                                                                        |
 | `CI_MERGE_REQUEST_EVENT_TYPE`                 | 12.3   | all    | The event type of the merge request, if [the pipelines are for merge requests](../merge_request_pipelines/index.md). Can be `detached`, `merged_result` or `merge_train`. |
 | `CI_NODE_INDEX`                               | 11.5   | all    | Index of the job in the job set. If the job is not parallelized, this variable is not set.                                                                                                                                                                                                                                                                 |
 | `CI_NODE_TOTAL`                               | 11.5   | all    | Total number of instances of this job running in parallel. If the job is not parallelized, this variable is set to `1`.                                                                                                                                                                                                                                    |

lib/gitlab/ci/features.rb

@@ -83,6 +83,10 @@ module Gitlab
       def self.coverage_report_view?(project)
         ::Feature.enabled?(:coverage_report_view, project)
       end
+
+      def self.expose_mr_description_predefined_variable?
+        ::Feature.enabled?(:ci_expose_mr_description_predefined_variable, default_enabled: true)
+      end
     end
   end
 end

spec/models/ci/pipeline_spec.rb

@@ -759,6 +759,7 @@ RSpec.describe Ci::Pipeline, :mailer, factory_default: :keep do
             'CI_MERGE_REQUEST_SOURCE_BRANCH_NAME' => merge_request.source_branch.to_s,
             'CI_MERGE_REQUEST_SOURCE_BRANCH_SHA' => pipeline.source_sha.to_s,
             'CI_MERGE_REQUEST_TITLE' => merge_request.title,
+            'CI_MERGE_REQUEST_DESCRIPTION' => merge_request.description,
             'CI_MERGE_REQUEST_ASSIGNEES' => merge_request.assignee_username_list,
             'CI_MERGE_REQUEST_MILESTONE' => milestone.title,
             'CI_MERGE_REQUEST_LABELS' => labels.map(&:title).sort.join(','),