Today I Learned how to lint a Jenkinsfile. Linting is the process of running some program that will verify your code for syntax errors. I’ve been finding myself writing a lot of Jenkinsfiles lately and it’s a bit of a pain to write directly into the Jenkins UI where the linting happens. There doesn’t seem to be any external plugins for IDE’s and editors, so in the meantime I was able to use Jenkins CLI to accomplish this in two steps.
Step 1: Download the Jenkins CLI
Open a browser and navigate to:
http//JENKINS_URL/jnlpJars/jenkins-cli.jar
Step 2: Execute the Linter
java -jar jenkins-cli.jar -s http://JENKINS_URL declarative-linter < /path/to/Jenkinsfile
And that’s it! It’s a simple but manual process. This could probably be easily scripted in an external tool in Eclipse or some other IDE. I tend to write my Jenkinsfiles in vi so it would be an interesting to see if I can simply record a macro to lint my current file.