Docker in jenkins openshift - docker

Question

When using docker in jenkins pipeline got a problem: "docker: command not found"
How can I start docker on OpenShift Jenkins?
Also, got no permissions to open plugins page in Jenkins.

Answer 1

The easiest way is to use jenkins installation provided by OpenShift
The doc for for jenkins in OpenShift is here : https://docs.openshift.com/container-platform/4.8/openshift_images/using_images/images-other-jenkins.html
To build docker images, the proposed solution is to use "source-to-image" (s2i) and/or use"BuildConfig"to manege "docker builds"
The doc also explains how to manage jenkins authentication/authorizations with jenkins integrated with OCP (OAuth + role bindings to OpenShift)
Bonus points: jenkins is configured with all the required plugins (k8s, OCP...) and it is automatically upgraded when you upgrade OCP

Answer 2

Using Jenkins on OpenShift, you won't find any Docker runtime on your Jenkins master - and probably not on the slaves either: cri-o being the preferred runtime (and only runtime, as of 4.x).
If you want to start containers, you're supposed to use any of the OpenShift or Kubernetes plugins: creating Pods. In OpenShift, you won't need to configure or install anything on Jenkins itself - aside from writing your pipeline. As long as your Jenkins ServiceAccount has edit or admin privileges over a Project, then it would be able to manage containers in the corresponding Namespace.
pipeline {
agent {
node { label 'maven' }
}
stages {
stage('clone') {
// clone the repository serving your YAMLs
}
stage('create') {
steps {
script {
openshift.withCluster() {
openshift.withProject() {
try {
timeout(5) {
objectsFromTemplate = openshift.process("-f", "/path/to/clone/directory/deploy.yaml", '-p', "FRONTNAME=${params.buildHash}",
'-p', "LDAP_IMAGE_TAG=${params.buildHash}", '-p', "ROOT_DOMAIN=${params.rootDomain}")
echo "The template will create ${objectsFromTemplate.size()} objects"
for (o in objectsFromTemplate) { o.metadata.labels["${templateSel}"] = "${templateMark}-${params.buildHash}" }
created = openshift.create(objectsFromTemplate)
created.withEach { echo "Created ${it.name()} from template with labels ${it.object().metadata.labels}" }
}
} catch(e) {
// DoSomething
}
}
}
}
}
}
}
}
If you don't have full access to your Jenkins admin interface, check the RoleBindings in that namespace: maybe you're not admin?
It won't prevent you from creating your own podTemplates (using ConfigMaps), Credentials (using Secrets) or jobs/jenkinsFiles (using BuildConfigs). While you may install additional plugins to Jenkins, adding/changing the content of the INSTALL_PLUGINS environment variable, in your Jenkins deployment.
Also note that the Jenkins ServiceAccount Token could be used authenticating against Jenkins as admin, working around Jenkins OpenShift OAuth integration.