Agent Skills: GitLab CI Debugger

GitLab CI Debugger

This skill enables Claude to investigate GitLab CI pipeline failures by:

1. Checking the current pipeline status for a branch or a specific pipeline ID
2. Identifying failed jobs
3. Retrieving failed job logs
4. Analyzing error messages and suggesting fixes

Prerequisites

• glab CLI installed and authenticated (glab auth status to verify)
• Git repository with GitLab remote configured (for automatic repo detection)

If glab is not installed or authenticated, provide instructions for setting it up:

• Install: https://gitlab.com/gitlab-org/cli#installation
• Authenticate: glab auth login

Instructions

When the user asks to check CI status, debug pipeline failures, or view job logs, use the glab CLI commands below. All commands auto-detect the GitLab project from the git remote in the current working directory. To target a different project, add -R <owner/group/project> to any command.

Handling GitLab URLs

When the user provides a full GitLab URL, parse it to extract the project path and the pipeline or job ID, then use -R to target that project. Always use the project from the URL, ignoring the local git remote.

Before constructing any command from a URL, validate the extracted values:

• Project paths must only contain letters, digits, hyphens, underscores, dots, and forward slashes.

• Pipeline and job IDs must be purely numeric.

• Job names must only contain letters, digits, hyphens, underscores, dots, colons, slashes, and spaces. If any value fails validation, reject it and ask the user to provide a corrected URL or ID.

• Pipeline URL format: https://gitlab.com/<group>/<project>/-/pipelines/<pipeline-id>

  • Extract: -R <group>/<project> and -p <pipeline-id>
  • Example: https://gitlab.com/my-org/my-project/-/pipelines/123456 becomes glab ci get -p 123456 -d -R my-org/my-project

• Job URL format: https://gitlab.com/<group>/<project>/-/jobs/<job-id>

  • Extract: -R <group>/<project> and <job-id>
  • Example: https://gitlab.com/my-org/my-project/-/jobs/789012 becomes glab ci trace 789012 -R my-org/my-project

Commands

1. Check Current Pipeline Status

   • Run glab ci get -d to get the latest pipeline for the current branch with job details
   • This shows the pipeline metadata (ID, status, ref, user) and a table of all jobs with their status, duration, and failure reason

2. Check Specific Branch

   • Use the -b flag to check the pipeline for a different branch: glab ci get -b <branch-name> -d

3. Check Specific Pipeline by ID

   • Use the -p flag to inspect a pipeline directly by its ID: glab ci get -p <pipeline-id> -d

4. View Job Logs

   • To retrieve logs for a specific job by its numeric ID: glab ci trace <job-id>
   • To retrieve logs for a job by name within a specific pipeline: glab ci trace <job-name> -p <pipeline-id>
   • To retrieve logs for a job by name on the current branch: glab ci trace <job-name>
   • To retrieve logs for a job by name on a specific branch: glab ci trace <job-name> -b <branch-name>

5. Find Merge Request for a Branch

   • If the user wants MR context (title, URL, reviewers): glab mr list -s <branch-name>

6. Troubleshoot CI Failures

   • First, get the pipeline status to identify failed jobs (steps 1-3 above)
   • Then, retrieve the full log of the failed job (step 4)
   • Analyze the log output to identify the error and suggest fixes

Examples

# Check CI pipeline status for the current branch
glab ci get -d

# Debug a failed pipeline by viewing the failed job's logs
glab ci trace 789012 -R my-org/my-project

Error Handling

• If glab is not found, instruct the user to install it
• If glab auth status reports unauthenticated, instruct the user to run glab auth login
• If a pipeline or job is not found, show the error and suggest checking the ID or branch name
• If the repo cannot be detected, suggest using -R <owner/group/project> or running from within the correct git repository