Nikhil Verma
- Sep 4, 2023
- 2 min read

Build Jenkins Pipeline Using Git, Docker Hub, Podman and Kubernetes - Part 4

Now our Jenkins and Kubernetes configuration completed.

Let's start with pipeline deployment:

We need to understand Architecture first :

On your local machine , let's build python application:

Python app : I have create python web app using flask :

from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello_world():
    return '<h1>Hello World from Flask!</h1>'

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=int("5000"), debug=True)

2. Dockerfile: A Dockerfile is a text document that contains all the commands a user needs to call on the command line to assemble an image. It is a set of instructions that Docker uses to build an image.

FROM python:3.9-slim-buster
ADD hello.py /
COPY . /app
WORKDIR /app
RUN pip3 install Flask
EXPOSE 5000
CMD [ "python3", "./hello.py" ]

3. For Kubernetes , we require Deployment yaml and Service Yaml .

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: hello
  name: hello
spec:
  replicas: 5
  selector:
    matchLabels:
      app: hello
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: hello
    spec:
      serviceAccountName: jenkins
      containers:
      - image: docker.io/vniks/jenkins-pipeline:v1
        name: python-hello-app
        ports:
        - name: hello
          containerPort: 5000
          protocol: TCP

Service.yaml

apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    app: hello
  name: hello-svc
spec:
  ports:
  - port: 5000
    nodePort: 30080
    protocol: TCP
    targetPort: 5000
  selector:
    app: hello
  type: NodePort

Apart from this application files we need Podman container to Build and push image. So we need to create image with Podman installed.

FROM jenkins/inbound-agent:alpine
USER root

RUN apk add --no-cache --update podman fuse-overlayfs

RUN sed -i 's/#mount_program/mount_program/' /etc/containers/storage.conf
RUN echo jenkins:100000:65536 >/etc/subuid
RUN echo jenkins:100000:65536 >/etc/subgid
USER jenkins

Build this image and push in your dockerhub repository.

podman login docker.io
podman build -t docker.io/vniks/python-hello-app:v1 .
podman push vniks/python-hello-app:v1

For creating Pipeline we need Jenkinsfile with all required stages :

podTemplate(containers: [
    containerTemplate(name: 'podman', image: 'vniks/podman-agent:v1', command: 'cat', privileged: true, user: 'root', ttyEnabled: true),
    containerTemplate(name: 'kubectl', image: 'lachlanevenson/k8s-kubectl:latest', command: 'cat', ttyEnabled: true)
  ],
  volumes: [
  hostPathVolume(mountPath: '/run/podman/podman.sock', hostPath: '/run/podman/podman.sock')
]) {

    node(POD_LABEL) {
        stage('Get a git project') {
            git 'https://github.com/vnikhil89/jenkins-pipeline.git'
            container('podman') {
                stage('Build a docker image and push') {
                  withCredentials([string(credentialsId: 'dockerhub-pwd', variable: 'dockerhubpwd')]){
                    sh 'podman login docker.io -u vniks -p ${dockerhubpwd}'
                    sh 'podman build -t docker.io/vniks/jenkins-pipeline:v1 .'
                    sh 'podman push docker.io/vniks/jenkins-pipeline:v1'
                  }
                }
            }
        stage('Deployment') {
            container('kubectl') {
                  sh 'kubectl apply -f hello.yaml'
                  sh 'kubectl apply -f hello-svc.yaml'
                }
            }
        }
    }
}

In Pod template we need to specify which containers we want to start along with Jenkins-Inbound agent container. In my case i have used Podman container to build and push image to docker hub. Second container Kubectl which is required to create deployment and service on Kubernetes cluster.

We also require socket for communication between podman container and podman.

Let's Create Pipeline :