Custom Pipeline Pod Templates
Kubernetes Pod Templates Defined in Pipeline Script
In this lab we will create a custom Kubernetes Pod Template containing a NodeJS container and an additional Docker container for executing tests. We also want to use a different version of the node container than the one provided by the nodejs-app Kubernetes Pod Template on your managed controller. In order to be able to control what containers and what container image version we use in our Pipeline, we will update the Jenkinsfile Pipeline script with an inline Kubernetes Pod Template definition.
- The Jenkins Kubernetes plugin allows you to use a standard Kubernetes Pod yaml manifest to define Pod Templates directly in your Pipeline script, either as a string or a file. We will do just that by creating a new
nodejs-pod.yamlfile and then adding ayamlFileparameter to theagentdeclaration with a value of the the repository relative path to that yaml file. The file provides a standard Kubernetes Pod spec to be used to create the Pod Template based agent. Navigate to your workshop insurance-frontend repository in your workshop GitHub Organization, make sure you are on theadd-jenkinsfilebranch, then click the Add file button towards the top right of the screen and select Create new file. IMPORTANT: Make sure you are on theadd-jenkinsfilebranch.
- Name the file
nodejs-pod.yamland add the following content:
kind: Pod
metadata:
name: nodejs-app
spec:
containers:
- name: nodejs
image: us-east1-docker.pkg.dev/core-workshop/workshop-registry/node:17-alpine
command:
- sleep
args:
- 99d
- name: testcafe
image: us-east1-docker.pkg.dev/core-workshop/workshop-registry/testcafe:1.18.0
command:
- sleep
args:
- 99d
securityContext:
runAsUser: 1000
This is a standard Kubernetes Pod Specification.
- At the bottom of the screen enter a commit message, leave Commit directly to the
add-jenkinsfilebranch selected and click the Commit new file button. - Now we need to update our Pipeline to use that file. Open the GitHub editor for the Jenkinsfile Pipeline script in the add-jenkinsfile branch of your workshop insurance-frontend repository.
- Replace the
agentsection of the Teststagewith the following - note that the value of theyamlFileparameter is the name of the pod template file we created:
agent {
kubernetes {
yamlFile 'nodejs-pod.yaml'
}
}
Your complete add-jenkinsfile branch Jenkinsfile should match the following:
pipeline {
agent none
stages {
stage('Test') {
agent {
kubernetes {
yamlFile 'nodejs-pod.yaml'
}
}
steps {
container('nodejs') {
echo 'Hello World!'
sh 'node --version'
}
}
}
}
}
- Commit the changes and then navigate to the add-jenkinsfile branch of your insurance-frontend job on your CloudBees CI Managed Controller. The job will run successfully. Also, note the output of the
sh 'node --version'step - it isv17.x.xinstead ofv14.x.x:
Also notice that the final Kubernetes pod spec for the agent is printed out in the logs and is merge of a default template (with the jnlp container) and the nodejs-pod.yamlpod spec from your insurance-frontend repository:
---
apiVersion: "v1"
kind: "Pod"
metadata:
annotations:
buildUrl: "http://cbci-pipeline-controller.controllers.svc.cluster.local/cbci-pipeline-controller/job/pipelines/job/insurance-frontend/job/beedemo-dev-patch-1/7/"
runUrl: "job/pipelines/job/insurance-frontend/job/beedemo-dev-patch-1/7/"
labels:
jenkins: "agent"
jenkins/label-digest: "9aa0cb9549a28ee62427ae2431380aed159ef6cf"
jenkins/label: "pipelines_insurance-frontend_beedemo-dev-patch-1_7-mn9xq"
cloudbees.com/master: "cbci-pipeline-controller"
name: "pipelines-insurance-frontend-beedemo-dev-patch-1-7-mn9xq--l3zmv"
spec:
affinity:
podAntiAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- podAffinityTerm:
labelSelector:
matchExpressions:
- key: "com.cloudbees.cje.type"
operator: "In"
values:
- "master"
- "cjoc"
topologyKey: "kubernetes.io/hostname"
weight: 1
containers:
- args:
- "99d"
command:
- "sleep"
image: "us-east1-docker.pkg.dev/core-workshop/workshop-registry/node:17-alpine"
name: "nodejs"
volumeMounts:
- mountPath: "/home/jenkins/agent"
name: "workspace-volume"
readOnly: false
workingDir: "/home/jenkins/agent"
- args:
- "99d"
command:
- "sleep"
image: "us-east1-docker.pkg.dev/core-workshop/workshop-registry/testcafe:1.18.0"
name: "testcafe"
volumeMounts:
- mountPath: "/home/jenkins/agent"
name: "workspace-volume"
readOnly: false
workingDir: "/home/jenkins/agent"
- args:
- "/var/jenkins_config/jenkins-agent"
command:
- "/bin/sh"
env:
- name: "JENKINS_SECRET"
value: "********"
- name: "JENKINS_AGENT_NAME"
value: "pipelines-insurance-frontend-beedemo-dev-patch-1-7-mn9xq--l3zmv"
- name: "JENKINS_WEB_SOCKET"
value: "true"
- name: "JENKINS_NAME"
value: "pipelines-insurance-frontend-beedemo-dev-patch-1-7-mn9xq--l3zmv"
- name: "JENKINS_AGENT_WORKDIR"
value: "/home/jenkins/agent"
- name: "JENKINS_URL"
value: "http://cbci-pipeline-controller.controllers.svc.cluster.local/cbci-pipeline-controller/"
image: "us-east1-docker.pkg.dev/core-workshop/workshop-registry/agent:2.361.1.2"
imagePullPolicy: "IfNotPresent"
name: "jnlp"
resources:
limits: {}
requests: {}
tty: false
volumeMounts:
- mountPath: "/var/jenkins_config"
name: "volume-0"
readOnly: false
- mountPath: "/home/jenkins/agent"
name: "workspace-volume"
readOnly: false
workingDir: "/home/jenkins/agent"
enableServiceLinks: false
hostNetwork: false
nodeSelector:
kubernetes.io/os: "linux"
restartPolicy: "Never"
securityContext:
runAsGroup: 1000
runAsUser: 1000
serviceAccountName: "jenkins"
volumes:
- configMap:
name: "jenkins-agent"
optional: false
name: "volume-0"
- emptyDir:
medium: ""
name: "workspace-volume"
Finished Jenkinsfile for Custom Pipeline Pod Templates Lab
pipeline {
agent none
stages {
stage('Test') {
agent {
kubernetes {
yamlFile 'nodejs-pod.yaml'
}
}
steps {
container('nodejs') {
echo 'Hello World!'
sh 'node --version'
}
}
}
}
}