WordPress MySQL deployed by Jenkins

Hello, Here we are using Ubuntu 20.04.3 LTS OS as a base machine.

Overview

• Write Jenkinsfile for jenkins pipeline.
• Install Jenkins in minikube with the help of helm repo.
• Deploy WordPress and MySQL charts in minikube through Jenkins Pipeline.

Prerequisites

• Install Kubernetes
• Install Helm

Process

We are doing this deployment in a different namespace called demo.
For creating a new namespace you can use this command.

kubectl create namespace demo

For all below steps we are using the same namespace

Step 1: Writing Jenkinsfile for jenkins pipeline

1. Adding own jenkins slave image as an agent

this agent is common for all Jenkinsfiles

    agent {
        kubernetes {
            yaml '''
apiVersion: v1
kind: Pod
spec:
  containers:
  - name: shell
    image: jayagrawaldocker/jenkins:0.4
    command:
    - sleep
    args:
    - infinity
'''
            defaultContainer 'shell'
        }
    }

here I am adding jayagrawaldocker/jenkins:0.4 as a slave image. In this image I am taking jenkins/inbound-agent:latest as a base image and Install helm & kubernetes is that base image. You can also create your own image with below Dockerfile or continue with mine.

Dockerfile

ARG version=latest
FROM jenkins/inbound-agent:$version
LABEL maintainer='Jay Agrawal'

ARG HELM_VERSION=3.5.2

USER root
RUN apt-get update && apt-get install curl

# install helm
RUN mkdir /tmp/helm \
RUN cd /tmp/helm  \
RUN curl -s https://get.helm.sh/helm-v${HELM_VERSION}-linux-amd64.tar.gz  | tar zxvf - \
RUN cp /tmp/helm/linux-amd64/helm /usr/local/bin/helm  \
RUN chmod +x /usr/local/bin/helm  \
RUN rm -rf /tmp/helm

# install Kubernetes CLI
# See https://storage.googleapis.com/kubernetes-release/release/stable.txt
RUN curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.19.0/bin/linux/amd64/kubectl \
  && chmod +x ./kubectl \
  && mv ./kubectl /usr/local/bin/kubectl
USER jenkins

3. Stages in Jenkinfiles:
   Here we are creating 2 jenkinsfile for WordPress & MySQL for seperate pipeline and 1 jenkinsfile is for deploying both WordPress & MySQL in single pipeline.

    stages {
        stage('version cheak') {
            steps {
                sh 'helm version'
                sh 'kubectl version'
            }
        }
        stage('helm install mysql'){
            steps{
                sh 'helm upgrade --install mysql sql -n demo'
            }
        }
        stage('helm install wordpress'){
            steps{
                sh 'helm upgrade --install wp wordpress -n demo'
            }
        }
    }

Given above stages is for Jenkinsfile for deploying both WordPress & MySQL in one pipline. Where as If you continue with only stage1 and stage2 and remove stage3 i.e. helm install wordpress then you can use same file for Jenkinsfile1 and with stage1 and stage3 i.e. if you remove stage2 helm install mysql then the same file is used as jenkinsfile2.

Step 2: Install Jenkins in minikube Jenkins

1. You can refer to official documents for Jenkins installation and skip step 2: Install Jenkins in minikube Jenkins or you can continue with us.
2. Get Repo Info

helm repo add jenkins https://charts.jenkins.io
helm repo update

3. Install Chart

# Helm 3
helm install -n demo helm-jenkins2 jenkins/jenkins

4. Wait for the container to start

kubectl get pods -namespace demo

Initial output

NAME              READY   STATUS    RESTARTS       AGE
helm-jenkins-0    0/2     Running   0               1m

It will take 5-10 mins according to your machine Configuration, repeat the 4th command, until the addition of all containers in the pool.

Final output

NAME              READY   STATUS    RESTARTS       AGE
helm-jenkins-0    2/2     Running   0              10m

5. Generate a password for admin user

kubectl exec --namespace demo -it svc/helm-jenkins -c jenkins -- /bin/cat /run/secrets/chart-admin-password && echo

6. For creating the link between minikube and local machine.

kubectl --namespace demo port-forward svc/helm-jenkins 8080:8080

7. Go to the link http://127.0.0.1:8080 and log in with the username -> admin and password generated by the second-last command. (5th point)

Step 3: Creating a new job in Jenkins

For running MySQL and WordPress in a single pipeline

1. First go to the new item and create a new pipeline job with any name. (recommended name demo)
2. Then go in the last in the pipeline section there in Definition select Pipeline script for SCM.
3. In SCM select git and in Repository URL past https://github.com/JayAgrawalgit/wordpress-mysql-deploy-by-jenkins.git or HTTPS link of this repo which is present in the top green code button.
4. In Branches to build enter */main.
5. In Script Path enter Jenkinsfile.
6. Apply and Save.
7. Now Build the Project

For running MySQL and WordPress in 2 different pipelines.

1. First go to the new item and create a new pipeline job with any name. (recommended name MySQL-pipeline)
2. Then go in the last in the pipeline section there in Definition select Pipeline script for SCM.
3. In SCM select git and in Repository URL past https://github.com/JayAgrawalgit/wordpress-mysql-deploy-by-jenkins.git or HTTPS link of this repo which is present in the top green code button.
4. In Branches to build enter */main.
5. In Script Path enter Jenkinsfile1 for MySQL.
6. Apply and Save.

Note: As e need to perform individual job run for both MySQL and WordPress we need to take care of that especially

11. For running the job individual In Script Path enter Jenkinsfile2 for WordPress, rest of the procedure as above
12. Apply and Save.
13. Now Build the Project name MySQL-pipeline and if It will run SUCCESS then build the project with the name WordPress-pipeline.

If you encountered the below error in running the pipeline:

1. failed to query with labels: secrets are forbidden: User "system:serviceaccount:demo:default" cannot list resource "secrets" in API group "" in the namespace "demo"
   then run

Given command is Strictly not recommended in production environment, This is only a work around.

kubectl create clusterrolebinding permissive-binding --clusterrole=cluster-admin --user=admin --user=kubelet --group=system:serviceaccounts:demo

For more information kubernetes.io Jenkins.io

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