Effective Use of Groovy Variables in Regex Patterns within Jenkinsfiles

Описание: Learn how to seamlessly integrate `Groovy` variables into regex patterns in Jenkinsfiles to avoid common pitfalls and enhance your CI/CD processes.
---
This video is based on the question https://stackoverflow.com/q/68479148/ asked by the user 'StoneThrow' ( https://stackoverflow.com/u/5437543/ ) and on the answer https://stackoverflow.com/a/68482939/ provided by the user 'injecteer' ( https://stackoverflow.com/u/1682820/ ) 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: Jenkinsfile/Groovy: how to use variables in regex pattern find-counts?

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.
---
Mastering Regex Patterns with Groovy Variables in Jenkinsfiles

In the world of automation and continuous integration, Jenkins is a powerhouse, especially when combined with Groovy scripts. However, one common challenge developers face is utilizing variables effectively within Regular Expressions (regex) in Jenkinsfiles. This guide will explore a specific problem regarding the application of Groovy variables in regex patterns and provide a straightforward solution.

The Problem: Regex and Groovy Variables

When working with Jenkins declarative pipelines, regex patterns need to be precise. A user encountered an issue when attempting to dynamically include a variable in a regex pattern:

Here's the original issue:

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

The second line that used the variable depth generated an error:

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

It seems the variable is causing the issue—let's break down how to correctly utilize it!

The Solution: String Interpolation in Groovy

The problem here is that the regex engine does not recognize the variable depth unless it is properly interpolated. In Groovy, you need to prefix the variable with a dollar sign $ when using it inside the regex pattern. Here's the modified code:

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

Why Does This Work?

In Groovy, string interpolation is supported for different types of strings, including regex patterns. The following are the types that allow for variable substitution:

Standard Double Quotes:

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

Slashy Strings: Used primarily for regex literals:

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

Multi-line Double-Quoted Strings:

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

By using {$depth} inside a slashy string, you effectively tell Groovy to replace the variable with its value during pattern matching.

Conclusion

In conclusion, utilizing Groovy variables in regex patterns within Jenkinsfiles requires an understanding of string interpolation. By ensuring that your variables are properly prefixed with $, you can avoid common pitfalls such as PatternSyntaxException. This small adjustment can significantly improve the robustness and flexibility of your Jenkins automation scripts.

Feel free to reach out in the comments if you have any questions or additional tips regarding Groovy scripting and Jenkinsfiles!