The method I had more comfort using was this: https://github.com/firecow/gitlab-ci-local
install gitlab-runner: https://docs.gitlab.com/runner/install/linux-manually.html
https://blog.asksven.io/posts/testing-gitlab-ci-pipelines-locally/
https://medium.com/@umutuluer/how-to-test-gitlab-ci-locally-f9e6cef4f054