Скачать или смотреть Can I Use Variable Expansion in GitLab CI Variables Block?

Discover how to extract version numbers from GitLab CI commit tags with `variable expansion` and improve your CI/CD processes.
---
This video is based on the question https://stackoverflow.com/q/72109297/ asked by the user 'boojum' ( https://stackoverflow.com/u/4221522/ ) and on the answer https://stackoverflow.com/a/72116000/ provided by the user 'sytech' ( https://stackoverflow.com/u/5747944/ ) 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: Can I use variable expansion in Gitlab CI variables block?

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.
---
Can I Use Variable Expansion in GitLab CI Variables Block?

In the world of software development, Continuous Integration (CI) plays a pivotal role in automating the process of integrating code changes. GitLab CI, a popular CI/CD software, allows you to define variables that can dynamically adjust based on your project’s needs. However, developers often face challenges when trying to manipulate these variables in a straightforward manner, particularly when it comes to extracting specific parts of them.

One common question among users is whether it’s possible to use variable expansion within the variables: block of a GitLab CI configuration file. A developer recently raised a concern about extracting version numbers from their commit tags, formatted like @ org/service@ v1.0.0, to utilize them in subsequent jobs. Let's delve into the circumstances around this issue and explore practical solutions.

Understanding the Issue

The specific requirement here is to extract only the version number (e.g., v1.0.0) from the GitLab predefined variable $CI_COMMIT_TAG, which represents the current commit tag of the project. Here's a simplified breakdown of the situation:

Predefined Variable: $CI_COMMIT_TAG stores the tag of the current commit.

Desired Result: Extract the version number and make it available throughout the jobs.

Original Attempt: The developer tried to declare a variable TAG using shell commands like sed within the variables: block using the syntax:

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

However, this approach didn't work as expected, leading to confusion and the need for a proper resolution.

The Solution: Alternative Approaches

1. Leveraging before_script

Unfortunately, using shell utilities directly within the variables: block is not supported in GitLab CI configurations. However, you can still achieve your goal by overriding certain elements of your jobs, even if they come from an included configuration file.

Here's how to do it:

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

In this case, you would define the TAG variable in the before_script, which runs before the main script execution.

2. Utilizing artifacts:reports:dotenv

Another effective method is to create a job that generates an artifact containing the desired variable using artifacts:reports:dotenv. Here’s how you can structure it:

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

In this configuration:

The create-tag job runs a script to extract the version number and writes it to variables.env.

The artifacts section ensures that other jobs can access the variables defined within the dotenv file, thus making the TAG variable available for subsequent processes.

Conclusion

While direct variable expansion within the variables: block of GitLab CI is not feasible, utilizing a combination of before_script and artifacts:reports:dotenv offers a viable workaround. By implementing these techniques, you can streamline your CI configuration to better suit your workflow, ultimately enhancing efficiency and clarity in your development process.

Remember, each project might require unique solutions, and understanding the limits of the tool is essential. By experimenting with the recommended methods above, you can effectively manage your variables and ensure your CI/CD pipeline runs smoothly.

We hope this guide helps clarify the situation and provides you with practical implementation strategies for handling variables in GitLab CI!