Where can environment variables be defined in GitLab CI/CD?

In GitLab CI/CD, environment variables can be defined within the .gitlab-ci.yml file or in the project settings, which provides flexibility for managing configuration that might differ between development, staging, and production environments.

Defining environment variables in the .gitlab-ci.yml file allows for the configuration to be versioned alongside your code, making it easy to keep track of any changes, and ensuring that the CI/CD pipeline uses the correct settings based on the code's context. This method also allows developers to set variable values that are specific to particular jobs or stages within the pipeline.

Alternatively, setting environment variables in the project settings provides a centralized interface for managing them. This is especially useful for sensitive information like API keys or tokens, as these can be stored securely and accessed throughout the CI/CD process without hardcoding them into the script.

This dual capability of defining variables offers great flexibility for various deployment scenarios and security considerations, making it a key feature in GitLab CI/CD workflows.