How i declare the 'prebuild' script in package.json, to run only in the gitlab pipeline?

2 min read 04-09-2024

How i declare the 'prebuild' script in package.json, to run only in the gitlab pipeline?

Running Pre-build Scripts Only in Your GitLab Pipeline

When building your application, you might need to run certain scripts (like linting and testing) before the actual build process. However, you might not want these scripts to execute locally every time you run yarn build. This is where conditional script execution comes into play.

This article will guide you on how to configure your package.json to execute prebuild scripts exclusively within your GitLab pipeline.

Understanding the Problem

The core issue is that you want to run specific scripts before your build script, but only when building within the GitLab CI/CD environment. Running them locally during development can add unnecessary time and complexity.

Solution: Environment Variables

The most effective way to achieve this is by utilizing environment variables. Your GitLab CI/CD pipeline can define environment variables that are accessible within your scripts.

Here's how you can implement this:

Define an environment variable in your GitLab CI/CD configuration:

image: node:16

stages:
  - build

build:
  stage: build
  script:
    - yarn build
  environment:
    - CI=true

Utilize the environment variable in your package.json:

{
  "scripts": {
    "prebuild": "if [ \"$CI\" = \"true\" ]; then npm test && npm run lint; fi",
    "build": "react-scripts build"
  }
}

Explanation

In the GitLab CI/CD configuration, we set the environment variable CI to true.
The package.json script uses a conditional statement: if [ "$CI" = "true" ]; then ... fi.
If the environment variable CI is true (only within the GitLab pipeline), the npm test and npm run lint commands will execute.
If CI is not true (running locally), the conditional statement will be skipped.

Advantages

Clean separation: This approach clearly separates the execution of pre-build scripts based on the environment.
Efficiency: Avoids unnecessary script execution during local development.
Maintainability: Easily control which scripts run in different environments by modifying environment variables.

Additional Notes

You can use different environment variables for various scenarios. For example, you could have a DEV variable for development-specific scripts.
Remember to always escape special characters (like $ and ") within your scripts to avoid unexpected behavior.

Conclusion

By leveraging environment variables, you can effectively manage the execution of your pre-build scripts, ensuring they only run within your GitLab pipeline. This allows for a cleaner and more efficient development workflow.

Please remember to adapt this solution to your specific project needs. If you have any questions or encounter issues, refer to the GitLab CI/CD documentation and Stack Overflow for additional support.