Add a CI_COMMIT_MESSAGE predefined variable

app/models/ci/pipeline.rb

@@ -284,6 +284,14 @@ module Ci
       commit.try(:title)
     end
 
+    def git_commit_full_title
+      commit.try(:full_title)
+    end
+
+    def git_commit_description
+      commit.try(:description)
+    end
+
     def short_sha
       Ci::Pipeline.truncate_sha(sha)
     end
@@ -491,6 +499,9 @@ module Ci
         .append(key: 'CI_PIPELINE_ID', value: id.to_s)
         .append(key: 'CI_CONFIG_PATH', value: ci_yaml_file_path)
         .append(key: 'CI_PIPELINE_SOURCE', value: source.to_s)
+        .append(key: 'CI_COMMIT_MESSAGE', value: git_commit_message)
+        .append(key: 'CI_COMMIT_TITLE', value: git_commit_full_title)
+        .append(key: 'CI_COMMIT_DESCRIPTION', value: git_commit_description)
     end
 
     def queued_duration

spec/models/ci/build_spec.rb

@@ -1518,7 +1518,10 @@ describe Ci::Build do
         { key: 'CI_PROJECT_VISIBILITY', value: 'private', public: true },
         { key: 'CI_PIPELINE_ID', value: pipeline.id.to_s, public: true },
         { key: 'CI_CONFIG_PATH', value: pipeline.ci_yaml_file_path, public: true },
-        { key: 'CI_PIPELINE_SOURCE', value: pipeline.source, public: true }
+        { key: 'CI_PIPELINE_SOURCE', value: pipeline.source, public: true },
+        { key: 'CI_COMMIT_MESSAGE', value: pipeline.git_commit_message, public: true },
+        { key: 'CI_COMMIT_TITLE', value: pipeline.git_commit_title, public: true },
+        { key: 'CI_COMMIT_DESCRIPTION', value: pipeline.git_commit_description, public: true }
       ]
     end
 

spec/models/ci/pipeline_spec.rb

@@ -173,7 +173,7 @@ describe Ci::Pipeline, :mailer do
     it 'includes all predefined variables in a valid order' do
       keys = subject.map { |variable| variable[:key] }
 
-      expect(keys).to eq %w[CI_PIPELINE_ID CI_CONFIG_PATH CI_PIPELINE_SOURCE]
+      expect(keys).to eq %w[CI_PIPELINE_ID CI_CONFIG_PATH CI_PIPELINE_SOURCE CI_COMMIT_MESSAGE CI_COMMIT_TITLE CI_COMMIT_DESCRIPTION]
     end
   end