Check if we're in a GitHub Action / Travis CI / Circle CI etc. testing environment

Question

I would like to programmatically determine if a particular Python script is run a testing environment such as

• GitHub action
• Travis CI
• Circle CI

etc. I realize that this will require some heuristics, but that's good enough for me. Are certain environment variables always set? Is the user name always the same? Etc.

Answer 1

An environment variable is generally set for each CI/CD pipeline tool.

The ones I know about:

os.getenv("GITHUB_ACTIONS")
os.getenv("TRAVIS")
os.getenv("CIRCLECI")
os.getenv("GITLAB_CI")

Will return true in a python script when executed in the respective tool environment.

e.g:

• os.getenv("GITHUB_ACTIONS") == "true" in a Github Action workflow.
• os.getenv("CIRCLECI") == "true" in a CircleCI pipeline.
• ...

PS: If I'm not mistaken, to identify the python script is being executed in Jenkins or Kubernetes Service host, the behavior isn't the same.

Answer 2

I think the CI environment variable is defined in most environments

References for your 3 cases:

• GitHub CI
• GitLab CI
• Travis CI
• Circle CI