DevOps project using Git, Jenkins, ansible and Docker

In this project, we will be see how to use Git, Jenkins, Ansible, DockerHub, Docker to DEPLOY on a docker container.,

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PreRequisites

1. Git
2. Jenkins
3. Ansible
4. Setup ansible client and install docker.
5. Docker Hub account

Stage-01 : Create a web page

Put all the web page code file into github

Stage-02 : Create a Docker file

• Create a Docker file into github

FROM centos:latest
MAINTAINER [email protected]
RUN yum install httpd git -y
RUN git clone https://github.com/praveensirvi1212/webdev /var/www/html
WORKDIR /var/www/html
CMD ["/usr/sbin/httpd","-D","FOREGROUND"]
EXPOSE 80

Stage-03 : Jenkins configuration

1. Install java and git
2. Install jenkins
3. Login to Jenkins console
4. Create Jenkins job with free style, Fill the following details,

   • Source Code Management:

     • Repository : https://github.com/praveensirvi1212/Docker.git
     • Branches to build : */main

   • Build:

     • Send files or execute commands over SSH

       • Name: jenkins_server
       • Exec Command:
         • rsync -avh /var/lib/jenkins/workspace/web/Dockerfile root@ansible-server's_private-ip:/opt

     • Send files or execute commands over SSH

       • Name: ansible_server
       • Exec Command:
         • cd /opt/docker
         • docker image build -t $JOB_NAME:v1.$BUILD_ID .
         • docker image tag $JOB_NAME:v1.$BUILD_ID praveensirvi/$JOB_NAME:v1.$BUILD_ID
         • docker image tag $JOB_NAME:v1.$BUILD_ID praveensirvi/$JOB_NAME:latest
         • docker image push praveensirvi/$JOB_NAME:v1.$BUILD_ID
         • docker image push praveensirvi/$JOB_NAME:latest
         • docker image rmi $JOB_NAME:v1.$BUILD_ID praveensirvi/$JOB_NAME:v1.$BUILD_ID praveensirvi/$JOB_NAME:latest

So for we used latest docker image to build a container, but what happens if latest version is not working?
One easiest solution is, maintaining version for each build. This can be achieved by using environment variables.

Here we use 2 variables

• BUILD_ID - The current build id

• JOB_NAME - Name of the project of this build. This is the name you gave your job when you first set it up.

  • Post Build:
    • Send files or execute commands over SSH
      • Name: ansible_server
      • Exec Command:
        • ansible-playbook /playbooks/docker.yml

1. Login to Docker host and check images and containers. (no images and containers)
2. login to docker hub and check. shouldn't find images with for job_name:v1.build_id
3. Execute Jenkins job
4. check images in Docker hub. Now you could able to see new images pushed to Valaxy Docker_Hub

Troubleshooting:

1. Docker should be installed on ansible server
2. Should login to "docker hub" on ansible server
3. Docker admin user should be part of docker group

Stage-04 : Ansible_server

1. Install Ansible and Docker

2. Start Docker daemon

3. Login into Docker Hub

4. Write a yml file to create a container (file name : /playbooks/docker.yml)

     ---
     - hosts: web
       tasks:
          - name: stop container
            shell: docker container stop myweb
          - name: remove container
            shell: docker container rm myweb
          - name: remove docker image
            shell: docker image rm praveensirvi/web
          - name: docker container create
            shell: docker run -d --name myweb -p 8080:80 praveensirvi/web
   

Troubleshooting: Makesure you have opened required ports on AWS Security group for this server.

Stage-05 : Apache_server

1. Install Docker and start Docker daemon

Final output :

References

[1] - Jenkins Docs - Building Software Projects