yml commands to commit back the generated index

.gitlab-ci.yml

@@ -25,6 +25,31 @@ prepare:index:
     paths:
       - .tmp
 
+prepare:commitIndex:
+  image:
+    name: alpine/git:latest
+    entrypoint: [""]
+  stage: deploy
+  rules:
+    - if: '$CI_PIPELINE_SOURCE == "merge_request_event" && $CI_COMMIT_MESSAGE !~ /tmpBranch/ && $CI_COMMIT_MESSAGE !~ /Update index/'
+  before_script:
+    - git fetch --all
+    - url_host=`git remote get-url origin | sed -e "s/https:\/\/gitlab-ci-token:.*@//g"`
+    - git remote set-url origin "https://$GIT_ACCESS_USER:$GIT_ACCESS_TOKEN@${url_host}"
+    - git config user.name $GIT_ACCESS_USER
+    - git config user.email $GIT_ACCESS_EMAIL
+  script:
+    - cp .tmp/index.md .
+    - git branch -D tmpBranch || true
+    - git checkout -b tmpBranch
+    - git add --all
+    - git commit -m "Update index"
+    - git checkout $CI_COMMIT_REF_NAME
+    - git pull origin $CI_COMMIT_REF_NAME
+    - git merge tmpBranch --ff
+    - git push origin $CI_COMMIT_REF_NAME || true
+    - git branch -D tmpBranch
+
 # build
 # ------------------------------------------------------------------------------------
 
@@ -55,9 +80,6 @@ build:pages:
     # Display, which configuration is used
     - 'echo "Configuration: " && cat ".ci/_config_$CI_COMMIT_REF_NAME.yml"'
 
-    # retrieve index from previous stage
-    - cp .tmp/index.md .
-
     # Run Jekyll with custom configuration
     - bundle exec jekyll build -d build --config "_config.yml,.ci/_config_$CI_COMMIT_REF_NAME.yml"