CI/CD Defined
In modern software projects many teams utilize the concept of Continuous Integration (CI) and Continuous Delivery (CD). By setting up a tool chain that continuously builds, tests, and stages software releases, a team can ensure that their product can be reliably released at any time. OpenShift can be an enabler in the creation and management of this tool chain.
In this lab we walk through creating a simple example of a CI/CD pipeline utilizing Jenkins, all running on top of OpenShift! The Jenkins job will trigger OpenShift to build and deploy a test version of the application, validate that the deployment works, and then tag the test version into production.
Create a new project
Create a new project named “cicd-YOUR# ”.
Create the project cicd-YOUR#
$ oc new-project cicd-YOUR#
Switch modes to
click "Create Project".
Fill in the Name and Display Name of the project as "cicd-YOUR# " and click "Create"
Instantiate a Jenkins server in your project
$ oc new-app jenkins-ephemeral
In "Developer" mode, click "+Add"
Select the "From Catalog" button, and filter on "Jenkins (Ephemeral)". Then select "Jenkins (Ephemeral)".
Click
Select the Project cicd-YOUR# from "Namespace"
Scroll down to the bottom, and click
Create a sample application configuration
Let's download a tempate for a sample application, so that we can integrate it into our pipeline
$ wget https://raw.githubusercontent.com/openshift/origin/master/examples/jenkins/application-template.json
Next, let's update the template to not use an deprecated container, as it's base. We'll use Red Hat's Universal Base Image as the platform, instead:
$ sed 's/nodejs-010-centos7/nodejs-10/g' application-template.json > NEW-Template.json
And last, we'll instantiate the template.
$ oc create -f NEW-Template.json
Click "Home" and "Search"
From the "Select Resource" (which defaults to Service) dropdown menu, select "Template"
Click "..." and select "Edit Template"
Find and replace "nodejs-010-centos7" with "nodejs-10"
Click "Save"
With either editing method, please make sure that your template looks like this, when it is complete:
Your timestamp and uid will vary
{
"kind": "Template",
"apiVersion": "v1",
"metadata": {
"name": "nodejs-helloworld-sample",
"annotations": {
"description": "This example shows how to create a simple nodejs application in openshift origin v3",
"iconClass": "icon-nodejs",
"tags": "instant-app,nodejs"
}
},
"objects": [
{
"kind": "Service",
"apiVersion": "v1",
"metadata": {
"name": "frontend-prod"
},
"spec": {
"ports": [
{
"name": "web",
"protocol": "TCP",
"port": 8080,
"targetPort": 8080,
"nodePort": 0
}
],
"selector": {
"name": "frontend-prod"
},
"type": "ClusterIP",
"sessionAffinity": "None"
},
"status": {
"loadBalancer": {}
}
},
{
"kind": "Route",
"apiVersion": "v1",
"metadata": {
"name": "frontend"
},
"spec": {
"to": {
"kind": "Service",
"name": "frontend"
},
"tls": {
"termination": "edge"
}
}
},
{
"kind": "DeploymentConfig",
"apiVersion": "v1",
"metadata": {
"name": "frontend-prod"
},
"spec": {
"strategy": {
"type": "Rolling",
"rollingParams": {
"updatePeriodSeconds": 1,
"intervalSeconds": 1,
"timeoutSeconds": 120
}
},
"triggers": [
{
"type": "ImageChange",
"imageChangeParams": {
"automatic": true,
"containerNames": [
"nodejs-helloworld"
],
"from": {
"kind": "ImageStreamTag",
"name": "origin-nodejs-sample:prod"
}
}
},
{
"type": "ConfigChange"
}
],
"replicas": 1,
"selector": {
"name":"frontend-prod"
},
"template": {
"metadata": {
"labels": {
"name": "frontend-prod"
}
},
"spec": {
"containers": [
{
"name": "nodejs-helloworld",
"image": " ",
"ports": [
{
"containerPort": 8080,
"protocol": "TCP"
}
],
"resources": {
"limits": {
"memory": "${MEMORY_LIMIT}"
}
},
"terminationMessagePath": "/dev/termination-log",
"imagePullPolicy": "IfNotPresent",
"securityContext": {
"capabilities": {},
"privileged": false
}
}
],
"restartPolicy": "Always",
"dnsPolicy": "ClusterFirst"
}
}
}
},
{
"kind": "Service",
"apiVersion": "v1",
"metadata": {
"name": "frontend"
},
"spec": {
"ports": [
{
"name": "web",
"protocol": "TCP",
"port": 8080,
"targetPort": 8080,
"nodePort": 0
}
],
"selector": {
"name": "frontend"
},
"type": "ClusterIP",
"sessionAffinity": "None"
}
},
{
"kind": "ImageStream",
"apiVersion": "v1",
"metadata": {
"name": "origin-nodejs-sample"
}
},
{
"kind": "ImageStream",
"apiVersion": "v1",
"metadata": {
"name": "origin-nodejs-sample2"
}
},
{
"kind": "ImageStream",
"apiVersion": "v1",
"metadata": {
"name": "origin-nodejs-sample3"
}
},
{
"kind": "ImageStream",
"apiVersion": "v1",
"metadata": {
"name": "nodejs-10"
},
"spec": {
"dockerImageRepository": "${NAMESPACE}/nodejs-10"
}
},
{
"kind": "BuildConfig",
"apiVersion": "v1",
"metadata": {
"name": "frontend",
"labels": {
"name": "nodejs-sample-build"
}
},
"spec": {
"triggers": [
{
"type": "GitHub",
"github": {
"secret": "secret101"
}
},
{
"type": "Generic",
"generic": {
"secret": "secret101"
}
}
],
"source": {
"type": "Git",
"git": {
"uri": "https://github.com/openshift/nodejs-ex.git"
}
},
"strategy": {
"type": "Source",
"sourceStrategy": {
"from": {
"kind": "ImageStreamTag",
"name": "nodejs-10:latest"
}
}
},
"output": {
"to": {
"kind": "ImageStreamTag",
"name": "origin-nodejs-sample:latest"
}
},
"resources": {}
}
},
{
"kind": "DeploymentConfig",
"apiVersion": "v1",
"metadata": {
"name": "frontend"
},
"spec": {
"strategy": {
"type": "Rolling",
"rollingParams": {
"updatePeriodSeconds": 1,
"intervalSeconds": 1,
"timeoutSeconds": 120
}
},
"triggers": [
{
"type": "ImageChange",
"imageChangeParams": {
"automatic": false,
"containerNames": [
"nodejs-helloworld"
],
"from": {
"kind": "ImageStreamTag",
"name": "origin-nodejs-sample:latest"
}
}
},
{
"type": "ConfigChange"
}
],
"replicas": 1,
"selector": {
"name":"frontend"
},
"template": {
"metadata": {
"labels": {
"name": "frontend"
}
},
"spec": {
"containers": [
{
"name": "nodejs-helloworld",
"image": " ",
"ports": [
{
"containerPort": 8080,
"protocol": "TCP"
}
],
"resources": {
"limits": {
"memory": "${MEMORY_LIMIT}"
}
},
"terminationMessagePath": "/dev/termination-log",
"imagePullPolicy": "IfNotPresent",
"securityContext": {
"capabilities": {},
"privileged": false
}
}
],
"restartPolicy": "Always",
"dnsPolicy": "ClusterFirst"
}
}
}
}
],
"parameters": [
{
"name": "MEMORY_LIMIT",
"displayName": "Memory Limit",
"description": "Maximum amount of memory the container can use.",
"value": "512Mi"
},
{
"name": "NAMESPACE",
"displayName": "Namespace",
"description": "The OpenShift Namespace where the ImageStream resides.",
"value": "openshift"
},
{
"name": "ADMIN_USERNAME",
"displayName": "Administrator Username",
"description": "Username for the administrator of this application.",
"generate": "expression",
"from": "admin[A-Z0-9]{3}"
},
{
"name": "ADMIN_PASSWORD",
"displayName": "Administrator Password",
"description": "Password for the administrator of this application.",
"generate": "expression",
"from": "[a-zA-Z0-9]{8}"
}
],
"labels": {
"template": "application-template-stibuild"
}
}
Create a sample application from template
Use the "oc process" command to create a simple nodejs application from the template file:
$ oc process nodejs-helloworld-sample -p NAMESPACE=registry.access.redhat.com/ubi7 | oc create -f -
You will see the followig:
service/frontend-prod created
route.route.openshift.io/frontend created
deploymentconfig.apps.openshift.io/frontend-prod created
service/frontend created
imagestream.image.openshift.io/origin-nodejs-sample created
imagestream.image.openshift.io/origin-nodejs-sample2 created
imagestream.image.openshift.io/origin-nodejs-sample3 created
imagestream.image.openshift.io/nodejs-10 created
buildconfig.build.openshift.io/frontend created
deploymentconfig.apps.openshift.io/frontend created
Click on "Workloads" and then "Deployment Configs", within the OpenShift console, to display the sample application configuration
Confirm you can access Jenkins
Get the route to the Jenkins server. Your HOST/PORT values will differ from the example below.
$ oc get route
NAME HOST/PORT PATH SERVICES PORT TERMINATION WILDCARD
frontend frontend-cicd.192.168.42.27.xip.io frontend <all> edge None
jenkins jenkins-cicd.192.168.42.27.xip.io jenkins <all> edge/Redirect None
Use Jenkins HOST/PORT to access through web browser
In "Developer" mode, under "Topology", click the arrow, in the upper right corner of the "jenkins" icon
Select "Login with OpenShift" from Jenkins login page
The OpenShift login page is displayed in a new browser tab.
Login with your OpenShift user name and password
Once logged in, click the [Allow selected permissions] button and you should see the Jenkins dashboard.
Create a Jenkins pipeline using OpenShift
We will be creating the following very simple (4) stage Jenkins pipeline.
- Build the application from source.
- Deploy the test version of the application.
- Submit for approval, then tag the image for production, otherwise abort.
- Scale the application.
The first step is to create a build configuration that is based on a Jenkins pipeline strategy. The pipeline is written in the GROOVY language using a Jenkins file format.
Use the OpenShift CLI or Web Console to create an OpenShift build configuration object.
Copy and paste the following into bash.
oc create -f - <<EOF
kind: "BuildConfig"
apiVersion: "v1"
metadata:
name: "pipeline"
spec:
strategy:
jenkinsPipelineStrategy:
jenkinsfile: |-
pipeline {
agent any
stages {
stage('buildFrontEnd') {
steps {
script {
openshift.withCluster() {
openshift.withProject() {
openshift.selector("bc", "frontend").startBuild("--wait=true", "--follow")
}
}
}
}
}
stage('deployFrontEnd') {
steps {
script {
openshift.withCluster() {
openshift.withProject() {
openshift.selector("dc", "frontend").rollout().latest()
}
}
}
}
}
stage('promoteToProd') {
steps {
script {
timeout(time: 15, unit: 'MINUTES') {
input message: "Promote to PROD?", ok: "Promote"
}
openshift.withCluster() {
openshift.withProject() {
openshift.tag("origin-nodejs-sample:latest", "origin-nodejs-sample:prod")
}
}
}
}
}
stage('scaleUp') {
steps {
script {
openshift.withCluster() {
openshift.withProject() {
openshift.selector("dc", "frontend-prod").scale("--replicas=2")
}
}
}
}
}
}
}
EOF
Expected output:
buildconfig.build.openshift.io/pipeline created
Click on "Build" and then "Create Build Config"
Use the following OpenShift build configuration to create the pipeline.
kind: "BuildConfig"
apiVersion: "build.openshift.io/v1"
metadata:
name: "pipeline"
spec:
strategy:
jenkinsPipelineStrategy:
jenkinsfile: |-
pipeline {
agent any
stages {
stage('buildFrontEnd') {
steps {
script {
openshift.withCluster() {
openshift.withProject() {
openshift.selector("bc", "frontend").startBuild("--wait=true", "--follow")
}
}
}
}
}
stage('deployFrontEnd') {
steps {
script {
openshift.withCluster() {
openshift.withProject() {
openshift.selector("dc", "frontend").rollout().latest()
}
}
}
}
}
stage('promoteToProd') {
steps {
script {
timeout(time: 15, unit: 'MINUTES') {
input message: "Promote to PROD?", ok: "Promote"
}
openshift.withCluster() {
openshift.withProject() {
openshift.tag("origin-nodejs-sample:latest", "origin-nodejs-sample:prod")
}
}
}
}
}
stage('scaleUp') {
steps {
script {
openshift.withCluster() {
openshift.withProject() {
openshift.selector("dc", "frontend-prod").scale("--replicas=2")
}
}
}
}
}
}
}
Choose +Add -> YAML, from Developer mode
Then copy and paste the above build configuration definition and choose "Create".
Start the pipeline
Using the OpenShift Web Console, in "Administrator" mode, choose Builds -> Build Configs, and then click on "pipeline"
From the "Actions" menu, choose "Start Build"
When the pipeline starts, OpenShift uploads the pipeline to the Jenkins server for execution. As it runs, the various stages trigger OpenShift to build and deploy the frontend microservice. After a Jenkins user approves the frontend deployment, Jenkins triggers OpenShift to tag the image stream with the ":prod" tag then scales the frontend-prod deployment for (2) replicas.
The Jenkins dashboard should indicate that a new build is executing.
Back in the OpenShift Web Console, watch the pipeline execute. Once the "deployFrontEnd" stage completes, you should be able to visit the route for the frontend service in a web browser.
Click on "Input Required" and you should get redirected to the Jenkins Web Console
Click on "Paused for Input", in the left-side menu
You can now approve the deployment to the PROD environment
Now return to the OpenShift Web Console and watch the pipeline finish.
Confirm the frontend-prod has deployed 2 pods.
Now create a secure route with TLS edge termination the frontend-prod service so the application can be visited.
Go to Networking -> Routes, and click
Fill out the form, as shown, and then click
Confirm both the test and production services are available
Browse to both services
Use the oc get routes command to get the HOST/PORT (URLs) needed to access the frontend and frontend-prod services. Your HOST/PORT values will differ
from the example below.
$ oc get routes
NAME HOST/PORT PATH SERVICES PORT TERMIN
ATION WILDCARD
frontend frontend-cicd-1.apps.alexocp43.redhatgov.io frontend <all> edge
None
frontend-prod frontend-prod-cicd-1.apps.alexocp43.redhatgov.io frontend-prod web edge/R
edirect None
jenkins jenkins-cicd-1.apps.alexocp43.redhatgov.io jenkins <all> edge/R
edirect None
Use a web browser to visit the HOST/PORT (URLs) for the frontend and frontend-prod services. Don't forget the https:// prefix.
Alternately, you can use curl, right from your terminal
$ curl -k https://frontend-prod-cicd-1.apps.alexocp43.redhatgov.io 2>/dev/null | head -6
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Welcome to OpenShift</title>
In "Developer" mode, select the "cicd-1" project, and click on "Topology"
Click on the arrow, at the upper right corner of the "frontend-prod" icon, to launch the web page
Service web page displayed:
Edit the pipeline.
Now make a change to the pipeline. For example, in the scaleUp stage, change the number of replicas to 3.
Technically speaking, a rebuild from source is not needed to scale up a deployment. We use this simple example to illustrate how a pipeline may be edited within OpenShift.
If you are comfortable using the vi editor:
oc edit bc/pipeline
Here is an excerpt from the file, showing the necessary change:
stage('scaleUp') {
steps {
script {
openshift.withCluster() {
openshift.withProject() {
openshift.selector("dc", "frontend-prod").scale("--replicas=3")
Save your changes and run the pipeline again to confirm the frontend-prod deployment has deployed 3 pods.
Summary
In this lab you have very quickly and easily constructed a basic Build/Test/Deploy pipeline. Although our example was very basic it introduces you to a powerful DevOps feature of OpenShift through the leveraging of Jenkins. This can be extended to support complex real-world continuous delivery requirements. Read more about the use of Jenkins on OpenShift here and more about Jenkins here.
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