Unable to use the Docker Pipeline plugin with RHEL 8 and 9

2 minute readKnowledge base

Issue

When trying to use the Docker Pipeline plugin on RHEL 8 or 9, it fails with errors such as:

ERROR: The docker version is less than v1.7. Pipeline functions requiring 'docker exec' (e.g. 'docker.inside') or SELinux labeling will not work.
Finished: FAILURE

Note: Error message from JENKINS-63233: Unable to use it with podman-docker

Environment

Resolution

Read the following Knowledge Base article to learn about the change from docker to podman: Is the docker package available for Red Hat Enterprise Linux 8 and 9?

The recommended resolution to this problem is not utilize the Docker Pipeline plugin on RHEL 8 or 9, and instead directly invoke the desired podman commands from a Pipeline sh step.

Workaround 1: Install Docker CE

If you do not want to refactor your Pipelines, a workaround, although not supported, would be to install the docker-ce packages for CentOS:

Then when running a Pipeline with a step such as:

   docker.image('maven:3.8.6-openjdk-8').inside {
     sh 'mvn --version'
   }

You will see that the plugin works again:

[Pipeline] withEnv
[Pipeline] {
[Pipeline] sh
+ docker pull maven:3.8.6-openjdk-8
...
[Pipeline] withDockerContainer
...
$ docker top ac24f17815df08510c3fe3230b46853f0a79b79c88e850d498371bb5a0c7de41 -eo pid,comm
[Pipeline] {
[Pipeline] sh
+ mvn --version
Apache Maven 3.8.6 (84538c9988a25aec085021c365c560670ad80f63)
Maven home: /usr/share/maven
Java version: 1.8.0_342, vendor: Oracle Corporation, runtime: /usr/local/openjdk-8/jre
Default locale: en, platform encoding: UTF-8
OS name: "linux", version: "4.18.0-477.13.1.el8_8.x86_64", arch: "amd64", family: "unix"
[Pipeline] }
$ docker stop --time=1 ac24f17815df08510c3fe3230b46853f0a79b79c88e850d498371bb5a0c7de41
$ docker rm -f --volumes ac24f17815df08510c3fe3230b46853f0a79b79c88e850d498371bb5a0c7de41
[Pipeline] // withDockerContainer
[Pipeline] }
[Pipeline] // script
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
Finished: SUCCESS

Workaround 1: Tested product/plugin versions

Workaround 2: Emulate Docker CLI with Podman

This workaround will still be using Podman to run the containers, but will be emulating Docker CLI with a shell script, similar to Emulating Docker CLI with Podman.

We will create a modified docker script to remove the user argument -u UID:GID that the Docker Pipeline plugin adds here, so when calling Podman it can run as the user Podman decides the container should run as, as per simplytim.io/using-podman-with-docker-plugin-in-jenkins/ Using Podman with Docker Plugin in Jenkins.

Create a /usr/local/bin/docker script with the content:

#!/usr/bin/bash
[ -e /etc/containers/nodocker ] || \
echo "Emulate Docker CLI using podman. Create /etc/containers/nodocker to quiet msg." >&2

declare -a finalopts
finalopts=()

USERCHECK=0
for o in "$@"; do
  if [[ "$o" = "-u" && $USERCHECK = 0 ]] ; then
    USERCHECK=1
    continue
  fi
  if [[ $USERCHECK = 1 ]] ; then
    USERCHECK=0
    continue
  fi

  finalopts+=("$o")
done

exec podman "${finalopts[@]}"
▼

Then make the script executable, and optionally touch the nodocker file to clear the warning message:

chmod +x /usr/local/bin/docker
touch /etc/containers/nodocker
▼

With these steps, your Pipelines and your controller don’t require changes for your jobs to continue working well with Podman.

Here’s a demo using this workaround:

docker.image('docker.io/maven:3.8.6-openjdk-8').inside {
  sh 'mvn --version'
}
▼

When run, this build is successful:

successful build using Docker CLI emulation

Related reading https://www.redhat.com/sysadmin/rootless-podman

Workaround 2: Tested product/plugin versions