Скачать или смотреть How to Properly Evaluate GitLab CI Rules

Discover how to check GitLab CI rules effectively to ensure your CI pipelines run only on specific hosts. Learn to troubleshoot and structure your `.gitlab-ci.yml` file for optimal performance!
---
This video is based on the question https://stackoverflow.com/q/70583836/ asked by the user 'Jim Hunziker' ( https://stackoverflow.com/u/6160/ ) and on the answer https://stackoverflow.com/a/70588842/ provided by the user 'Origin' ( https://stackoverflow.com/u/12289730/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How do I check how Gitlab CI rules are being evaluated?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Properly Evaluate GitLab CI Rules: A Comprehensive Guide

When working with GitLab CI (Continuous Integration), you might encounter scenarios where you want your CI jobs to run under specific conditions. For instance, you may want to restrict your CI pipelines to execute only on a certain host, regardless of the CI settings in the graphical interface. This guide will guide you through the essential steps to evaluate GitLab CI rules for optimal performance and troubleshooting.

Understanding the Problem

In your .gitlab-ci.yml file, you might have set up rules to control the execution of CI pipelines by utilizing environment variables like CI_SERVER_HOST. A common scenario might involve the following configuration:

[[See Video to Reveal this Text or Code Snippet]]

In this setup, the CI job is expected to run only if the CI_SERVER_HOST is equal to run-here.example.com. If it is not, the pipelines would ideally not execute. However, you might find that with this rule, your pipelines don’t run at all, leaving you confused about the functionality of the rules.

The Challenge

Pipelines Not Running: Despite confirming that your host value is correct, removing the rule allows pipelines to run everywhere, indicating that there might be an issue with how the rules are structured.

The Solution: Adjusting Your CI Workflow

To fix the issue and ensure your pipelines work as intended, you will need to adjust your .gitlab-ci.yml to include a fallback rule that allows it to run in all other cases. This is achievable with the following configuration:

[[See Video to Reveal this Text or Code Snippet]]

Breakdown of the Configuration

Initial Rule:

if: '$CI_SERVER_HOST != "run-here.example.com"': This checks if the server host is not run-here.example.com. If this condition is true, the job will not run due to when: never.

Fallback Rule:

when: always: This ensures that in all other cases, regardless of the previous conditions, the pipeline will execute.

Benefits of This Approach

Control: You maintain strict control over where your jobs execute based on the server host.

Flexibility: The fallback rule provides the flexibility to allow jobs to run elsewhere if the condition is not met, avoiding complete locks on your CI processes.

Clarity: Simplifying the rules helps you and your team quickly understand what to expect from the CI behavior.

Conclusion

By adjusting your GitLab CI rules as demonstrated, you can effectively evaluate and control how and when your CI pipelines run. This not only ensures clarity in your deployment processes but also enhances the overall efficiency of your CI/CD workflows. When issues arise with your CI configurations, closely reviewing your rules and making necessary adjustments can lead to a seamless integration experience.

Implement these changes in your .gitlab-ci.yml and watch your GitLab CI jobs run smoothly on the desired host! If you have any questions, feel free to reach out in the comments below. Happy coding!