Disable Merge Request Pipeline? Easy Steps You Must Know!

Disabling Merge Request Pipelines: Easy Steps You Must Know!

Merge request pipelines are invaluable for automated testing and code quality checks before integrating changes. However, there are scenarios where temporarily disabling them becomes necessary. This guide provides clear, step-by-step instructions on how to disable the merge request pipeline in various platforms, focusing on the main objective: disabling the merge request pipeline.

Understanding When to Disable Merge Request Pipelines

Before diving into the "how," let’s briefly cover the "why." Disabling merge request pipelines isn’t always the best practice. Consider it carefully. Some common reasons include:

• Emergency Hotfixes: When a critical production issue requires immediate attention, waiting for pipeline completion might be impractical.
• Non-Critical Changes: For documentation updates or minor cosmetic fixes, a full pipeline might be overkill.
• Troubleshooting Pipeline Issues: If the pipeline itself is failing, temporarily disabling it can help isolate the problem.
• Resource Constraints: During peak usage times, temporarily disabling non-essential pipelines can free up resources.

Methods for Disabling Merge Request Pipelines (General Overview)

The specific method for disabling a merge request pipeline varies depending on the platform you’re using (e.g., GitLab, GitHub, Azure DevOps). However, the underlying principle is usually one of these two:

1. Skipping the Pipeline Trigger: Configure the system to ignore pipeline triggers associated with merge requests.
2. Bypassing Pipeline Execution: Trigger the merge request but explicitly tell the system to skip the pipeline execution.

Disabling Merge Request Pipelines in GitLab

GitLab offers several ways to disable or bypass pipelines. Here’s a detailed look at the most common methods:

Method 1: Using [skip ci] or [ci skip] in Commit Messages

This is the simplest and most direct method. By including [skip ci] or [ci skip] (case-insensitive) in the commit message of the merge request’s source branch, you can instruct GitLab to skip pipeline execution for that specific commit.

• How it works: GitLab’s CI/CD engine detects these phrases in the commit message and automatically skips the pipeline.
• Example: "Fix: Resolved minor typo [skip ci]"

Method 2: Using the only:merge_requests or except:merge_requests Directive in .gitlab-ci.yml

You can modify your .gitlab-ci.yml file to conditionally exclude pipelines from running on merge requests.

• The only:merge_requests keyword: This ensures that the job runs only when a merge request is present. If you remove this clause, your pipeline will not run on merge requests. Alternatively, you might modify the rules that trigger pipelines.

• The except:merge_requests keyword: This explicitly excludes the job from running when a merge request is present.

• Example using except:

  job:
script:
- echo "This job will NOT run on merge requests"
except:
- merge_requests

• Example using only:

  job:
script:
- echo "This job will ONLY run on tags or branches, NOT merge requests"
only:
- tags
- branches

Method 3: Using Environment Variables and rules in .gitlab-ci.yml

This allows for more granular control using rules based on conditions like the CI_PIPELINE_SOURCE environment variable.

• How it works: CI_PIPELINE_SOURCE indicates the source of the pipeline trigger. Merge requests have a specific value for this variable. You can use rules to check this variable and conditionally skip jobs.

• Example:

  job:
script:
- echo "This job will NOT run on merge requests"
rules:
- if: '$CI_PIPELINE_SOURCE != "merge_request_event"'
when: always
- when: never

  This example checks if the pipeline source is NOT merge_request_event. If it’s not, the job runs. If it is a merge request, the second rule prevents the job from ever running.

Disabling Merge Request Pipelines in GitHub Actions

GitHub Actions provides methods to disable pipelines triggered by pull requests (GitHub’s equivalent of merge requests).

Method 1: Skipping with Commit Messages

Similar to GitLab, you can use special phrases in your commit messages to skip workflows. GitHub Actions recognizes phrases like [skip ci], [ci skip], ***NO_CI***, [skip actions], or [actions skip].

• How it Works: When GitHub Actions detects one of these phrases in a commit message included in the pull request, it will skip running any workflows triggered by that commit.

Method 2: Conditional Workflow Execution using if Statements

You can add conditional checks to your workflow file (.github/workflows/*.yml) to prevent workflows from running on pull requests based on specific conditions.

• Using github.event_name Context: The github.event_name context variable indicates the event that triggered the workflow. For pull requests, this will often be pull_request.

• Example:

  name: My Workflow
on:
push:
branches:
- main
pull_request:
branches:
- main

  jobs:
my_job:
if: github.event_name != 'pull_request'
runs-on: ubuntu-latest
steps:
- name: Run some commands
run: echo "Running the job!"

  In this example, the my_job will only run if the event is NOT a pull request.

Method 3: Using Branches and Paths Filters

Workflow triggers can be configured with branch and path filters. By strategically defining these filters, you can prevent workflows from running on pull requests.

• How it works: If your workflow is designed to run only on specific branches (e.g., main) and doesn’t include any logic for handling pull requests targeting those branches, the workflow will effectively be skipped for pull requests. Similarly, if it only runs on changes to files in a docs/ directory, and the PR only changes code, the pipeline skips.

• Example:

  name: Build and Test
on:
push:
branches:
- main
jobs:
build:
runs-on: ubuntu-latest
steps:
# ... build steps ...

  This workflow will only trigger on push events to the main branch. Pull requests to main won’t trigger this workflow.

Disabling Merge Request Pipelines in Azure DevOps

Azure DevOps provides various ways to control pipeline execution for pull requests.

Method 1: Using Commit Message Prefixes

Azure DevOps supports skipping CI builds by including specific prefixes in the commit message, similar to GitLab and GitHub.

• Supported Prefixes: ***NO_CI*** or [skip ci] (case-insensitive).
• How it works: Azure DevOps detects these prefixes and skips the pipeline trigger.

Method 2: Disabling the Pull Request Trigger in Build Pipeline Settings

Azure DevOps allows you to disable the trigger that automatically starts a build pipeline when a pull request is created or updated.

1. Navigate to the build pipeline.
2. Edit the pipeline.
3. Go to the "Triggers" section.
4. Locate the "Pull request validation" trigger.

5. Disable the trigger.

   This will prevent the pipeline from running automatically for pull requests. You can still manually queue builds for pull requests if needed.

Method 3: Using Conditions in YAML Pipelines

You can use conditions in your YAML pipeline definition to conditionally exclude stages or jobs from running on pull requests.

• Using the Build.Reason Variable: The Build.Reason variable indicates the reason the build was triggered. For pull requests, it will typically be PullRequest.

• Example:

  stages:
- stage: MyStage
condition: ne(variables['Build.Reason'], 'PullRequest')
jobs:
- job: MyJob
steps:
- script: echo "This job will NOT run on pull requests"

  This example uses the ne() function (not equal) to check if the Build.Reason is not equal to PullRequest. If it’s not, the stage (and therefore the job within it) will execute. If it is a pull request, the stage will be skipped.

So, there you have it! Hopefully, you now have a clearer picture of how to dsiable the merge request pipleine. Go give it a try and streamline your workflow!