Jenkins always pull docker image from a declarative pipeline agent definition

Question

I have a working Jenkins pipeline defined with agent {any}.

But I want to try running the tests on a docker image. According to documentation I can do that the following way:

pipeline {
     agent {
         docker { image 'centos/python-27-centos7:latest' }
     }
     stages {
        ...
     }
}

The problem is that my instance of Jenkins is offline and with this configuration it will try to docker pull the image when running the project.

However I have the centos/python-27 image loaded in the docker (visible with docker images and it can be run with docker run -i -t centos/python-27-centos7 /bin/bash

Is there any way I can configure the agent in Jenkins so it doesn't try to pull the image from Docker Hub?

Answer 1

The Docker agent has an alwaysPull flag you can set to false or true:

agent {
  docker {
    alwaysPull false
    image 'foo/bar'
  }
}

---

Jenkins has a Pipeline Syntax Generator that can help in these cases. In the Job menu on the left side, there is an icon for "Pipeline Syntax".

There you can see some settings to help you generate your pipeline directives.