Test GitHub Action Pipeline Locally
A genuine problem
Recently, I was assigned to develop a workflow that will deploy the documentation whenever we push some changed to the main branch. The traditional way to develop GitHub Action pipeline is as following.
The problem is that we won’t know what’s wrong with our pipeline, unless we push it to GitHub and trigger the pipeline. This is not at all the best way to develop the pipeline.
It’s time to act locally
To test the pipeline, we can use an awesome tool called act. act allow us to execute the pipeline locally. It leverages the power of Docker and build or pull necessary images, as defined in the workflow file. What we get is a fast feedback. And we can fix it instantly and test it again.
How to Install it Locally?
While act is available for some platforms, the easiest way is to use the curl command.
cd ~
curl --proto '=https' --tlsv1.2 -sSf https://raw.githubusercontent.com/nektos/act/master/install.sh | sudo bashWhen we install it, it will create a bin folder in the current working directory. So, it’s recommended to change directory to home first and then run the curl command piped with sudo bash. Also, dont’ forget to add the bin directory to the $PATH.
Before we use act to run the workflow locally, we also need Docker. As act will build and run everything in a docker container, it needs the docker engine. Make sure you have it installed.
But it’s not enough to test a workflow. The project need to be synced to GitHub as well. You can checkout a sample repo that I have created here. You can create something similar or fork it and then you can test the workflow using act in your local machine.
Execution
Create a workflow in .github/workflows directory. Then you can run act as following.
# act -W <path-to-workflow>
act -W .github/workflows/mkdocs_test.ymlIf everything is fine, you will see job completed message at the end. Otherwise, fix the issues and rerun the tool.
The Problem
But still, there is one problem. While act is working, it’s still very limited. There are no other tools or methods to test the pipeline before committing the changes to GitHub. To know more check out the Unsupported functionality.
References
GitHub - HYP3R00T/act_with_mkdocs
https://github.com/HYP3R00T/act_with_mkdocs
Introduction - act - User Guide | Manual | Docs | Documentation
https://nektosact.com/
GitHub - nektos/act: Run your GitHub Actions locally 🚀
https://github.com/nektos/act
Docker: Accelerated Container Application Development
https://www.docker.com/
