Ahmet Can Aydemir

GitLab CI: Update MR with Jira Issue ID

• 2 min read

In my previous article, we enforced branch names and commit messages using git hooks. Now I’ll take it one step further: when an MR is opened, if the title contains a Jira issue ID (e.g. ISSUE-0000), we’ll fetch the Jira title and description and update the MR with them. The CI pipeline will fail if there’s no Jira issue ID in the title.

The plan is roughly this:

  1. Check whether the MR title contains an issue ID. If not, return a failing exit code. We’ll use a regex for this. $CI_MERGE_REQUEST_TITLE gives us the MR title.
  2. Extract the issue ID and pull data from the Jira API. A GET request to https://jira.<your-hostname>/rest/api/2/issue/ISSUE-0000 returns issue details as JSON.
  3. Read the summary and description fields from the JSON using jq and assign them to variables.
  4. Update the MR title and description through the GitLab API.

Curl and jq Setup

We need curl for our API requests and jq to parse JSON.

apk add --update curl && apk add --update jq && rm -rf /var/cache/apk/*

Issue ID Check

REGEX_ISSUE_ID="^(ISSUE-[0-9]+)"
ISSUE_ID_IN_MR=$(echo "$CI_MERGE_REQUEST_TITLE" | grep -o -E "$REGEX_ISSUE_ID")
[[ -z "$ISSUE_ID_IN_MR" ]]; then exit 1; fi

Parsing the Jira Issue

We store newline characters (\n) inside the DESCRIPTION_JSON variable because newlines cause problems when sent over a curl request.

JSON=$(curl -s -u <jira-username>:<jira-password> -X GET -H "Content-Type:application/json" "https://jira.<your-hostname>/rest/api/2/issue/$ISSUE_ID_IN_MR")

SUMMARY=$(echo "$JSON" | jq -r ".fields.summary")
DESCRIPTION=$(echo "$JSON" | jq -r ".fields.description")
DESCRIPTION_JSON=$(jq --null-input --compact-output --arg msg "$DESCRIPTION" '$msg')

Updating the Merge Request

You’ll need a GitLab personal access token. See the GitLab documentation for how to create one.

curl -v \
--data "{\"title\": \"${ISSUE_ID_IN_MR} ${SUMMARY}\"\"description\": ${DESCRIPTION_JSON}}" \
--fail \
--header "Content-Type:application/json; charset=utf-8" \
--header "PRIVATE-TOKEN:<private-token>" \
--output "/dev/null" \
--request PUT \
--show-error \
--silent \
--trace-ascii "/dev/stderr" \
--write-out "HTTP response: %{http_code}\n\n" \
"${CI_API_V4_URL}/projects/${CI_PROJECT_ID}/merge_request$CI_MERGE_REQUEST_IID"

Result

When we put it all together into a single GitLab CI YAML file, it looks like this:

check_mr:
  image: alpine
  stage: test
  script:
    - apk add --update curl && apk add --update jq && rm -rf /var/cache/apk/*
    - IFS=$"\n"
    - REGEX_ISSUE_ID="^(ISSUE-[0-9]+)"
    - ISSUE_ID_IN_MR=$(echo "$CI_MERGE_REQUEST_TITLE" | grep -o -E "$REGEX_ISSUE_ID")
    - if [[ -z "$ISSUE_ID_IN_MR" ]]; then exit 1; fi
    - JSON=$(curl -s -u <jira-username>:<jira-password> -X GET -H "Content-Type:application/json" "https://jira.<your-hostname>/rest/api/2/issue/$ISSUE_ID_IN_MR")
    - SUMMARY=$(echo "$JSON" | jq -r ".fields.summary")
    - DESCRIPTION=$(echo "$JSON" | jq -r ".fields.description")
    - DESCRIPTION_JSON=$(jq --null-input --compact-output --arg msg "$DESCRIPTION" '$msg')
    - |
      curl -v \
      --data "{\"title\": \"${ISSUE_ID_IN_MR} ${SUMMARY}\", \"description\": ${DESCRIPTION_JSON}}" \
      --fail \
      --header "Content-Type:application/json; charset=utf-8" \
      --header "PRIVATE-TOKEN:<private-token>" \
      --output "/dev/null" \
      --request PUT \
      --show-error \
      --silent \
      --trace-ascii "/dev/stderr" \
      --write-out "HTTP response: %{http_code}\n\n" \
      "${CI_API_V4_URL}/projects/${CI_PROJECT_ID}/merge_requests/$CI_MERGE_REQUEST_IID"
    only:
      - merge_requests

Add this file to your GitLab project as a CI configuration. After all that, your MR titles and descriptions will be much more organized and easier to understand.