Understanding Variable Substitution

2.2. Understanding Variable Substitution#

YAML itself cannot process or evaluate variables. However, many frameworks, such as in GitHub and GitLab allow the use of variables - environment variables - within YAML files

The Usage of $

GitHub and GitLab use $ to reference variables in YAML files.

$<variable> occurrences are substituted by the corresponding value prior to processing the YAML file.

Example

script:
  - branch=$CI_COMMIT_BRANCH

Note

GitHub also uses the ${{...}} syntax that can evaluate expressions, like scoped variables.