Building a CI/CD Pipeline with AWS, K8S, Docker, Ansible, Git, Github, Apache Maven, and Jenkins

In my previous article, I delved into the fascinating world of microservices - Microservice Architecture Patterns Part 1: Decomposition Patterns. This was the beginning of my comprehensive article series on microservices and their patterns.

While the logical step would be to continue with Part 2 of this series, I have decided that the next thing that I would like to explore and tell you about is the vital process of delivering these microservices to the end user seamlessly.

Content Overview

• Motivation
• [Module 1]: AWS EC2 Virtual Server
• [Module 2]: Jenkins Server
• [Module 3]: Git and Github
• [Module 4]: Apache Maven
• [Module 5]: Docker
• [Module 6]: Ansible
• [Module 7]: Kubernetes
• Conclusion
• About the Author

Motivation

CI/CD is a technique for delivering apps to customers, achieved by adding automation to different stages of app development. I believe that grasping CI/CD (Continuous Integration and Continuous Deployment) can empower developers to gain a better understanding of how backend project artifacts exist beyond the boundaries of the project repository. This comprehension can also create a fundamental shift in a developer's perspective. Instead of merely viewing their work as lines of code, they can start to embrace the broader context of their project as a valuable product.

In this article, we aim to demystify the CI/CD process through practical application. We'll take you through a step-by-step tutorial, breaking it down module by module, where you'll build a CI/CD pipeline manually. To do this, we'll harness the power of contemporary DevOps tools like AWS, Docker, Kubernetes, Ansible, Git, Apache Maven, and Jenkins. So, let's begin this journey!

[Module 1]: AWS EC2 Virtual Server

This module is dedicated to the creation of an AWS EC2 Virtual Server instance. As part of this article, you will be setting up three EC2 instances for Jenkins, Ansible, and Kubernetes. For now, you can proceed with the next modules and revisit this module in "[module 2]: Jenkins", “[module 6]: Ansible" and "[module 7]: Kubernetes" sections.

Step 1: Create an AWS Account

Go to https://aws.amazon.com.

Click the button Create an AWS Account.

Follow the instructions on the create account web page.

Step 2: Sign In to your AWS Account

Go to https://console.aws.amazon.com/console/home. Click the Sign In button.

Enter all necessary credentials on this web page.

Step 3: Find EC2 Virtual Server

Find EC2 in the search box.

Choose EC2 Virtual Server by clicking EC2 Service.

Click the button Launch Instance.

Step 4: Configure “Name and tags“ section

Go to the “Name and tags” section.

Provide a name for a new AWS EC2 Virtual Server instance in the “Name” section.

You can also add additional tags for your virtual server by clicking ”Add additional tags”.

Step 5: Configure “Application and OS Images (Amazon Machine Image)“ section

Go to the "Application and OS Images (Amazon Machine Image)" section.

Step 6: Configure “Instance type“ section

Go to the ”Instance type” section.

Step 7: Configure “Configure storage“ section

Go to the ”Configure storage” section.

Step 8: Configure “Network settings“ section

Go to the “Network settings“ section.

You need to set up the security of your virtual server. To do this,

1. Click on the “Create security group” button.
2. Add the name of your new security group in the “Security group name” section.
3. Add a description of your new security group in the “Description” section.

By default, your virtual server is accessible via (Type - SSH, Protocol - TCP, Port - 22). If you need additional connection types, add them by adding additional inbound security group rules.

Step 9: Configure “Key pair (login)“ section

Go to the ”Key pair (Login)” section.

Create a new key-pair if you haven't created it yet.

If you haven't created “key-pair” yet:

1. Click the “Create new key pair” button.
2. Give your new key-pair a name in the “Key pair name” section.
3. Select key-pair type RSA or ED25519. I choose the RSA type.
4. Select Private key file format. Choice of .pem and .ppk. I choose the .pem format.
5. Click on the “Create key pair” button.
6. You will get a pop-up window that will prompt you to download the Private key file. Agree and download the file to your computer.

Step 10: Launch the EC2 Virtual Server Instance

Launch the EC2 Virtual Server instance by clicking the button “Launch instance”.

After the completion of the EC2 Virtual Server instance creation process, you will see the following.

Then you should go to the “Instances“ section by clicking “View all instances” button.

Now you can see that your AWS EC2 Virtual Server instance is running.

[Module 2]: Jenkins Server

Now, let’s configure JenkinsServer on the EC2 Virtual Server instance.

Step 1: Create an AWS EC2 Virtual Server instance

You need a virtual server to run Jenkins.

Follow instructions from [Module 1]: AWS EC2 Virtual Server section of this tutorial to finish this step and create an EC2 virtual server instance with the name JenkinsServer.

Step 2: Connect to an AWS EC2 Virtual Server instance

Go to AWS Console home page → EC2 Management Console Dashboard → Instances.

Then you should choose JenkinsServer and then click the “Connect” button.

Then you will see this web page. You should again click the “Connect” button.

Now you can see EC2 virtual server instance online terminal.

Step 3: Download the Jenkins repository

Now you need to download Jenkins on your EC2 virtual server instance.

Follow these instructions:

1. Go to Jenkins download webpage.

2. You can see Stable (LTS) and Regular releases (Weekly) options. Choose Red Hat/Fedora/Alma/Rocky/CentOSLTS option.

You will see this web page.

3. Copy “sudo get..” command and execute it to download Jenkins files from the Jenkins repository on the Internet and save them to the specified location on your EC2 virtual server instance.

sudo wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat-stable/jenkins.repo

Now Jenkins is downloaded.

Step 4: Import Jenkins key

To finish the Jenkins installation, we need to import the Jenkins key.

To import the Jenkins key we need to copy the “sudo rpm..” command and execute it.

sudo rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io-2023.key

Step 5: Install Java

To run Jenkins, we need to install Java on our EC2 virtual server instance.

To install Java, use this command.

sudo amazon-linux-extras install java-openjdk11 -y

Verify whether Java was installed correctly using this command:

java -version

You will see something like that.

Step 6: Install fontconfig

To run Jenkins, you need to install fontconfig on our EC2 virtual server instance.

Use this command.

sudo yum install fontconfig java-11-openjdk -y

Step 7: Install Jenkins

In earlier steps, you configured your EC2 virtual server instance to use a specific Jenkins repository and then you imported the GPG key associated with this repository. Now, you need to run the command that will search all the repositories it knows about, including the Jenkins one you added, to find the Jenkins package. Once it finds the Jenkins package in the Jenkins repository, it will download and install it.

Let’s run this command.

sudo yum install jenkins -y

Step 8: Start Jenkins

You can start Jenkins using this command.

sudo systemctl start jenkins

To check that Jenkins is running use this command.

sudo systemctl status jenkins

You will see the output as it is on the screenshot below:

Jenkins should now be up and running.

Step 9: Access Jenkins

To access the Jenkins application, open any web browser and enter your EC2 instance’s public IP address or domain name followed by port 8080.

http://<your-ec2-ip>:8080

The first time you access Jenkins, it will be locked with an autogenerated password.

You need to display this password using the following command.

sudo cat /var/lib/jenkins/secrets/initialAdminPassword

Copy this password, return to your browser, paste it into the Administrator password field, and click "Continue".

Then you will be able to see this web page.

Now, you can use your Jenkins Server.

Step 10: Create new Jenkins pipeline

Now, as Jenkins is working fine, you can start creating the Jenkins pipeline. To create Jenkins pipeline you need to create a new “Freestyle project”. To create a new “Freestyle project” you need to go to the Jenkins dashboard and click the “New Item” button.

Enter the name of the Github “Freestyle project” (“pipeline” name is going to be used further) and then click the button “OK”.

Then provide the Description of the pipeline.

Then click the button “Apply” and “Save”. After that, it means you created the fundament of the pipeline which is going to be built in this tutorial.

[Module 3]: Git and Github

Now as Jenkins is running on AWS EC2 Virtual Server instance, you can configure Git with the pipeline.

Git as the most popular version control system enables us to pull the latest code from your project Github repository to your EC2 virtual server instance where your Jenkins is installed.

Step 1: Install Git

Use this command to install Git.

sudo yum install git -y

Now verify Git is working, using this command.

git --version

Now Git is working fine on EC2 Virtual Server instance.

Step 2: Open Jenkins dashboard

As Git is working fine on EC2 Virtual Server instance, we can integrate Jenkins with Git now.

To start this integration let’s install Jenkins Github plugin.

Go to Jenkins dashboard section.

Step 3: Open Jenkins Plugin Manager

Click the button “Manage Jenkins” and then click the button “Manage Plugins”.

Step 4: Find Github Jenkins plugin

Click the button “Available plugins”.

Find the Github plugin Search box.

Select Github plugin.

Step 5: Install Github Jenkins plugin

Select Github plugin. And then click the button “Install without restart”.

Wait for the end of the Github plugin downloading.

Yes! The Jenkins Github plugin is installed.

Step 6: Configure Github Jenkins Plugin

Now as the GitHub Jenkins plugin is installed, you can configure this plugin to integrate Jenkins with Git finally. To do that you need to return to the main page by clicking the button “Go back to the top page”.

Then on the main page, you need to click the button “Manage Jenkins” and then click the button “Global tool configuration”.

Then on the Global Tool Configuration web page you should go to the Git section.

In the Git section, you need to configure Git by providing the name and path to Git on the computer.

Then click the “Apply” and “Save” buttons**.**

Here, you have finished configuring the Jenkins Github plugin.

Step 7: Integrate Git into the pipeline

Now, as the Jenkins Github plugin is installed and configured, you're now able to utilize this plugin within your pipeline. This will allow your pipeline which you created in module 2 to pull your project code from the specified GitHub repository.

Well, to integrate this plugin into your pipeline you need to go to the Source Code Management section and choose Git in your pipeline. Then you need to provide your project repository URL. If your project repository is public on Github, you do not need to provide credentials. If the project repository is private on Github, you need to provide credentials.

You can use my project with the next Repositiry URL: https://github.com/Sunagatov/Hello.git.

Just copy and paste it to the “Repository URL” input. Then click the “Apply” and “Save” buttons to finish the integration Git with the pipeline.

Step 8: Test Git integrated into the pipeline

Now you can use your updated pipeline to pull a project from Github. To do that you need to click the **“Build Now”**button. As a result, you will see a successful build in the build history.

Open the first build from the build history.

Now you can see the successful job result of the first build. If you open your AWS EC2 terminal. You can check that the pipeline works well.

Just use this command.

cd /var/lib/jenkins/workspace/{your pipeline name}

This way you can see that your project from Github was pulled to your AWS EC2 virtual server instance.

[Module 4]: Apache Maven

Now that you have integrated Git into the pipeline, you can enhance the pipeline further by incorporating Apache Maven which enables you to build, test, and package your project. To do that you need to install Apache Maven on your AWS EC2 Virtual Server instance where Jenkins and Git were installed.

Step 1: Download Apache Maven

To download Apache Maven go to the “/opt” directory.

cd /opt

And then use this command.

sudo wget https://dlcdn.apache.org/maven/maven-3/3.9.4/binaries/apache-maven-3.9.4-bin.tar.gz

This command will download the latest official Apache Maven (check the latest version on the official Apache Maven website). To find the latest official Apache Maven release, use the link https://maven.apache.org/download.cgi.

Step 2: Extract Apache Maven from the archive

Use this command, to extract Apache Maven from the downloaded archive:

sudo tar -xvzf apache-maven-*.tar.gz

Step 3: Add JAVA_HOME and M2_HOME

Move to the root folder using this command.

cd ~

Edit .bash_profile file using this command.

vi .bash_profile

Add JAVA_HOME and M2_HOME variables.

Assign the path to JDK11 for JAVA_HOME and path to the maven directory for M2_HOME variable.

To find JDK path, use this command.

sudo find / -name java

Save the changes.

Then, execute this command to refresh system variables.

source .bash_profile

To verify $PATH, use this command.

echo $PATH

To verify Apache Maven, use this command.

mvn -v

If you have done everything correctly, you will be able to view the version of Apache Maven.

Step 4: Install Apache Maven Jenkins plugin

Since Apache Maven can be used on an EC2 instance, you can install the Apache Maven plugin to integrate it with the pipeline.

To achieve this, follow these steps:

1. Navigate to “Dashboard“ → “Manage Jenkins“ → “Manage Plugins“ → “Available”.
2. In the search box, enter “Maven”.
3. Choose “Maven Integration” plugin.

Wait for the end of the downloading process.

And then click the button “Go back to the top page”.

Step 5: Configure Apache Maven Jenkins plugin

With the successful installation of the Apache Maven Jenkins plugin, you are now able to utilize this plugin within the pipeline which you created and updated in modules 2 and 3.

To do so, follow these steps:

1. Go to “Dashboard“ → “Manage Jenkins“ → “Global Tool Coonfiguration“ → “JDK”
2. Click the button “Add JDK”.
3. Uncheck “Install automatically”.

Then go to “Maven” section. Click the button “Add Maven”. Uncheck “Install automatically”.

Then add name and MAVEN_HOME path.

Click the “Apply” and “Save” buttons.

Here, you have finished configuring the Apache Maven Jenkins plugin.

Step 6: Integrate Apache Maven into the pipeline

Now as the Apache Maven GitHub plugin is installed and configured, you're now able to utilize Apache Maven within your pipeline. This will allow your pipeline which you created in the “[module 2]: Jenkins Server” to build your project code to create a jar artifact.

To integrate Apache Maven into the pipeline you need to follow these steps:

1. Navigate to “Dashboard“ → “CI_CD_Pipeline“ → “Configure“ → “Build Steps”.
2. Click “Add build step” button.
3. Choose “Invoke top-level Maven targets” option.
4. Choose “Apache-Maven” as “Maven Version”.
5. Add “clean package” command to “Goals” input.
6. Click “Advanced“ button.
7. Add “pom.xml” to “POM” input.

Finally, you should click “Apply” and “Save” buttons to finish the integration of Apache Maven with the pipeline.

Step 7: Test Apache Maven integrated into the pipeline

Now you can use your updated pipeline to build your Github project. To do that you need to click the **“Build Now”**button. As a result, you will see a successful job result in the build history.

If you open your AWS EC2 terminal. You can check that the pipeline works well.

Just use this command.

cd /var/lib/jenkins/workspace/{your pipeline name}/target

This way you can see the JAR artifact, indicating the successful build of your project from GitHub.

[Module 5]: Docker

Now let’s create a new EC2 instance with the name "Ansible Server" where you are going to install Docker and Ansible.

Step 1: Launch an AWS EC2 Virtual Server instance

Use instructions from “Launch an AWS EC2 Virtual Server instance” section of this tutorial to finish this step. Do not forget to add a security group setup. It allows Docker and SSH to work on ports 8080 and 22 respectively.

Step 2: Connect to an AWS EC2 Virtual Server instance

Click the “Connect” button.

Now you can see the EC2 Virtual Server instance online terminal.

sudo chown ansible-admin:ansible-admin /opt/docker

Step 3: Install Docker on the Ansible EC2 virtual server.

Now you need to install docker on your Ansible EC2 instance. To do that you need to create a new docker folder.

sudo mkdir /opt/docker

Then, install docker by executing the next command.

sudo yum install docker -y

Step 4: Add current user to Docker group on Ansible EC2 virtual server

You need to add the current user “ansible-admin” to the Docker group on the “AnsibleServer” EC2 virtual server to give Docker admin privileges.

sudo usermod -a -G docker ansible-admin

You will need to logout and log back in for these changes to take effect.

Then you can execute the next command

id ansible-admin

to see that the new docker user exists.

Step 5: Launch Docker

Now as Docker is installed on the Ansible EC2 instance you can launch it by executing the next command.

sudo systemctl start docker

As Docker is started you can execute the next command

sudo systemctl status docker

to see that docker is active and running now.

Step 6: Create Dockerfile

In the final version of the pipeline, the process will involve creating a new Docker image from your GitHub project and pushing it to Docker Hub. To accomplish this, your GitHub project should contain a Dockerfile.

If you used the project “Hello” which was offered in “[Module 3]: Git and Github” module, then you don’t need to create a new Dockerfile as this project repository has already contained Dockerfile.

FROM eclipse-temurin:17-jre-jammy
ENV HOME=/opt/app
WORKDIR $HOME
ADD hello-0.0.1-SNAPSHOT.jar $HOME
ENTRYPOINT ["java", "-jar", "/opt/app/hello-0.0.1-SNAPSHOT.jar" ]

If you used your own project repository and it didn't contain a Dockerfile, you will need to create a new Dockerfile.

To create a new Dockerfile, execute the following command, which will create the new file.

sudo touch Dockerfile

Then you can fill this file with a sequence of commands that describe how to build a containerized application environment. These commands include actions like copying files into the image, installing software, setting environment variables, and configuring the container.

To fill the Dockerfile with these commands, execute the following command.

vim Dockerfile

The Dockerfile is ready to use.

Step 7: Login Docker

Now that your Dockerfile is prepared for use, proceed by copying your project's JAR artifact from the **"JenkinsServer"**EC2 instance and pasting it onto the "AnsibleServer" EC2 instance. It is important to note that this transfer will be automated through the pipeline further.

By completing this step, you'll be ready to test your Dockerfile along with the Docker environment you've set up.

Before you begin testing, make sure to authenticate yourself on Dockerhub. Execute the following command.

docker login

This command will prompt you to provide your Dockerhub login credentials, including your username and password.

With this, you have completed the process of logging into Docker and are now ready to proceed with testing.

Step 8: Testing the Docker environment and Dockerfile

With your successful login to Dockerhub completed, you are now ready to begin testing the Dockerfile you have prepared.

Execute this command to create a docker image.

docker build -t hello:latest .

Next, execute the subsequent command to establish a tag that will facilitate the image's upload to Dockerhub:

docker tag hello:latest zufarexplainedit/hello:latest

Finally, proceed to push the Docker image to Dockerhub through the execution of this command.

docker push zufarexplainedit/hello:latest

Following these steps, navigate to your Dockerhub account to verify whether you can see a new image or not.

You should now observe that the image has been effectively added. This outcome confirms the successful installation of the Docker environment and that your Dockerfile is correct.

[Module 6]: Ansible

Now let us configure the Ansible Server on the EC2 Virtual Server instance.

Step 1: Create an AWS EC2 Virtual Server instance

You need a virtual server to run Ansible.

Follow instructions from [Module 1]: AWS EC2 Virtual Server section of this tutorial to finish this step and create an EC2 virtual server instance for Ansible.

Step 2: Connect to an AWS EC2 Virtual Server instance

Go to AWS Console home page → EC2 Management Console Dashboard → Instances → AnsibleServer.

Then click the “Connect” button.

Then you will see this web page. You should again click the “Connect” button.

Now you can see the EC2 virtual server instance online terminal.

Now let’s configure Ansible Server on EC2 virtual server instance.

Step 3: Change the hostname of “AnsibleServer” AWS EC2 Virtual Server instance

The first thing you need to do when you want to configure AnsibleServer on EC2 virtual server instance is changing its hostname.

Let’s do it. Execute this command to open hostname file:

sudo vi /etc/hostname

You should see something like this:

Replace this hostname with “ansible-server”. Then, reboot it.

sudo init 6

Step 4: Add and configure a new user in “AnsibleServer” AWS EC2 Virtual Server instance

Now let’s add a new ansible-admin user to the AWS EC2 Virtual Server instance.

To do that use this command:

sudo useradd ansible-admin

Then, set the password for ansible-admin user.

sudo passwd ansible-admin

Also, you need to configure user privileges by editing the sudoers file.

sudo visudo

Add “ansible-admin ALL=(ALL) ALL” to this sudoers file.

Also, you need to edit /etc/ssh/sshd_config file to enable PasswordAuthentication.

sudo vi /etc/ssh/sshd_config

Then you need to reload the service to confirm these changes.

sudo service sshd reload

As a result of executing this command, you will see:

sudo su - ansible-admin

Step 5: Generate key in an AWS EC2 Virtual Server instance

You are planning to manage remote servers such as K8s EC2 virtual server instances further in this article. That is why you need to set up SSH keys.

ssh-keygen

As a result of executing this command, you will see:

Now SSH keys are generated and ready to use.

Step 6: Install Ansible

Now you can install Ansible on your “AnsibleServer” EC2 virtual server instance.

Let’s do it.

Execute this command to install Ansible.

sudo amazon-linux-extras install ansible2

To verify Ansible, use this command:

ansible --version

As a result of executing this command, you will see:

Step 7: Install Jenkins “Publish over SSH“ plugin on JenkinsServer EC2 instance

As Ansible is installed on your “AnsibleServer” EC2 virtual server instance, you can configure Jenkins to integrate it with Ansible. You need to install the “Publish over SSH” plugin to integrate Jenkins with the EC2 Virtual Server instance where Ansible is installed and with other EC2 Virtual Server instances where Kubernetes is installed.

Go to “Dashboard” → “Manage Jenkins” → “Configure System” → “Available plugins”.

Then enter “Publish over SSH“ in the search box.

Click the button “Install without restart”. Wait for the end of the downloading process.

Now the “Publish over SSH” plugin is installed on the Jenkins EC2 Virtual Server instance.

Step 8: Configure Jenkins “Publish over SSH“ plugin

With the successful installation of the Apache Maven Jenkins plugin, you are now able to utilize this plugin within the pipeline which you created and updated in modules 2 and 3.

To do so, follow these steps:

Go to “Dashboard“ → “Manage Jenkins” → “Configure System” → “Publish over SSH”.

Enter all required data as it is on the screenshot, including hostname, username, and private key (or password if applicable).

Then click the “Apply” and “Save” buttons.

Here you have finished configuring the “Publish over SSH“ Jenkins plugin.

Next, click “Test Configuration” to validate that the plugin is working correctly.

On the left side you can see that the test plugin configuration status is “Success”. It means the plugin configuration is correct.

Step 9: Create new Docker directory in AnsibleServer

You need to make a new folder on the AnsibleServer EC2 instance where the project JAR will be stored. This jar will be used for creating a Docker image later.

Let’s start.

Go to “/opt” folder in AnsibleServer EC2 instance.

cd /opt

Create a new folder “docker” there.

sudo mkdir docker

Give privileges to this “docker” folder.

sudo chown ansible-admin:ansible-admin docker

Now, check the “docker” folder privileges by executing this command.

ll

You can see that the “docker” folder is accessible with the “ansible-admin” user.

Step 10: Integrate “Publish over SSH“ Github plugin into the pipeline

Now as “Publish over SSH“ Github plugin is installed and configured, you're now able to integrate it into the pipeline which you created in the “[module 2]: Jenkins Server” to transfer a project jar artifact from “JenkinsServer” to “AnsibleServer”.

Well, to integrate “Publish over SSH“ Github plugin into the pipeline you need to follow these steps:

1. Navigate to “Dashboard“ → “CI_CD_Pipeline“ → “Configure“ → “Post-build Actions”.
2. Click “Add post-build action” button.
3. Choose “Send build artifacts over SSH” option.
4. Add “AnsibleServer” into “Name” input in “SSH Server” section**.**
5. Add  “target/*.jar” into “Source files” input in “Transfer Set” section**.**
6. Add  “target/” into “Remove prefix” input in “Transfer Set” section**.**
7. Add  “//opt/docker/” into “Remote directory” input in “Transfer Set” section**.**
8. For now, simply put an empty string in the 'Exec command' input under the 'Transfer Set' section.

Finally, you should click “Apply” and “Save” buttons to finish the integration “Publish over SSH“ plugin with the pipeline.

Step 11: Test “Publish over SSH“ Github plugin integrated into the pipeline

Now you can use your updated pipeline to transfer a project jar artifact from “JenkinsServer” to “AnsibleServer”. To do that you need to click the “Build Now” button. As a result you will see a successful job result in the build history.

If you open your “AnsibleServer” AWS EC2 terminal. You can check that the pipeline works well.

Just use this command.

cd /opt/docker

This way you can see the JAR artifact, indicating the successful build of your project from GitHub.

Step 12: Configure Ansible hosts

When you run an Ansible playbook, you specify the hosts it should run on. You can do this in two ways:

1. Specify hosts directly in the playbook: In your playbook, you can set the hosts parameter to a list of IP addresses or hostnames.
2. Use an inventory file: Ansible allows you to define a list of hosts in an inventory file and reference this file when running your playbook. The default inventory file is /etc/ansible/hosts.

By editing /etc/ansible/hosts, you can easily manage groups of hosts without having to write out their IP addresses each time you run a playbook.

Let’s find out the AnsibleServer EC2 instance host by executing the following command.

sudo ifconfig

After you find out AnsibleServer EC2 instance host, you can add it to the Ansible hosts file by executing the following command.

sudo vi /etc/ansible/hosts

You can also add “[ansible]” as a reference

Step 13: Configure Passwordless SSH authentication to localhost for Ansible

Ansible is designed for automating tasks on remote servers. Passwordless SSH authentication empowers Ansible to connect to those servers without the need for manual password entry.

Execute this command to create a secure connection from your computer to another computer (like the one at IP address 172.31.34.41), using the ansible-admin user's SSH key.

sudo ssh-copy-id -i /home/{your user name}/.ssh/id_rsa.pub {your user name}@{your host address}

In my case, it looks like this.

sudo ssh-copy-id -i /home/ansible-admin/.ssh/id_rsa.pub ansible-admin@172.31.34.41

Now you can see “Number of key(s) added: 1”. It means that the passwordless SSH authentication installation was successfully completed.

Step 14: Create a new Ansible playbook for Docker tasks

Now that Ansible is all set up and good to go, you can make a new Ansible playbook for your pipeline. This playbook will let Ansible create and send a new Docker image to Dockerhub.

Here's how you can do it:

1. Start by creating a new Ansible playbook file. Just use this command.

touch hello-app.yml

2. Then, edit the newly made hello-app.yml file. Open it up for editing with this command.

vi hello-app.yml

3. Inside the file, type in the following stuff.

---
- hosts: ansible
  user: root

  tasks:
    - name: create docker image
      command: docker build -t hello:latest .
      args:
        chdir: /opt/docker

    - name: create tag to push image onto dockerhub
      command: docker tag hello:latest zufarexplainedit/hello:latest

    - name: push docker image onto dockerhub
      command: docker push zufarexplainedit/hello:latest

The Ansible playbook for Docker tasks is ready to use.

Step 13: Test the Ansible playbook with Docker tasks

With Ansible, Ansible playbook, AnsibleServer, and JenkinsServer all properly configured, it is time to test the Ansible playbook.

Navigate to the location of your Ansible playbook.

cd /opt/docker

Then, execute the following command.

sudo -u ansible-admin ansible-playbook /opt/docker/hello-app.yml

Upon completion, you will see the successful execution outcome of your Ansible playbook.

Furthermore, take a moment to visit your Dockerhub account and verify whether a new image is now visible.

You should see the newly added image. This outcome confirms that your Ansible playbook is correct.

Step 14: Integrate Ansible Docker tasks into the pipeline

Now as “Publish over SSH“ Github plugin, Ansible and Docker are installed and configured, you're now able to integrate them all into the pipeline which you created in the “[module 2]: Jenkins Server” to transfer a project jar artifact from “JenkinsServer” to “AnsibleServer” and then build a new Docker image from your project and then push this Docker image onto Dockerhub.

To achieve it you need to follow these steps:

1. Navigate to “Dashboard“ → “CI_CD_Pipeline“ → “Configure“ → “Post-build Actions” → “Send build artifacts over SSH” .
2. Add “sudo -u ansible-admin ansible-playbook /opt/docker/hello-app.yml” command into “Exec command” input.

Finally, click “Apply” and “Save” buttons to finish the integration Ansible Docker tasks with the pipeline.

Step 15: Test “Ansible playbook with Docker tasks“ integrated into the pipeline

Now you can test your upgraded pipeline to seamlessly transfer a project jar artifact from “JenkinsServer” to “AnsibleServer” then build a new Docker image from your project and then push this Docker image onto Dockerhub. To do that you need to click the “Build Now” button. As a result you will see a successful job result in the build history.

Furthermore, take a moment to visit your Dockerhub account and verify whether a new image is now visible.

You should see the newly added image. This outcome confirms that your Ansible playbook with Docker tasks was successfully integrated into the pipeline.

[Module 7]: Kubernetes

Now let’s configure K8s on the EC2 instance. You are going to create a new EC2 instance and install their kubectl command-line tool for interacting with a Kubernetes cluster further.

Step 1: Launch an AWS EC2 Virtual Server instance

Use instructions from “Launch an AWS EC2 Virtual Server instance” section of this tutorial to finish this step.

Step 2: Connect to an AWS EC2 Virtual Server instance

Click the “Connect” button.

Now you can see the EC2 Virtual Server instance online terminal.

Step 3: Change the hostname of “KubernetesServer” AWS EC2 Virtual Server instance

The first thing you need to do when you want to configure KuberenetesServer on EC2 virtual server instance is to change its hostname.

Let’s do it. Execute this command to open hostname file:

sudo vi /etc/hostname

You should see something like this.

Replace this hostname with “kubernetes-server” and then reboot it.

sudo init 6

You will hostname was changed.

Step 4: Check AWS CLI version

Use this command to check the AWS version.

aws --version

This way you can see your current aws-cli version.

If you can see version aws-cli/1.18, you should download the latest version.

Step 5: Update AWS CLI

Now as you found out that you have an old aws-cli version on your EC2 instance you need to update it. To that go to AWS → Documentation → AWS Command Line Interface → User Guide for Version 2.

Copy-paste the curl command.

First, execute this command to download awscli version 2.

curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"

Wait for the downloading process to commence.

You should see something like this.

Second, you need to execute this command to unzip awscli version 2 archive.

unzip awscliv2.zip

Third, you should execute this command to install awscli version 2.

sudo ./aws/install

Then, reload the Kubernetes EC2 Virtual Server instance online terminal.

Next, use this command to check the AWS version

aws --version

You can see that aws cli has aws-cli/2.

Step 6: Install kubectl

Now you need to install kubectl command-line tool for interacting with a Kubernetes cluster further. To that you need to go to AWS → Documentation → Amazon EKS → User Guide → Installing or updating kubectl → Linux.

Or just click the link https://docs.aws.amazon.com/eks/latest/userguide/install-kubectl.html.

First, execute this command to download kubectl.

curl -O https://s3.us-west-2.amazonaws.com/amazon-eks/1.27.1/2023-04-19/bin/linux/amd64/kubectl

Wait for the downloading process.

You will see something like this.

Give permission to kubectl.

chmod +x kubectl

Move kubectl to /usr/local/bin folder.

sudo mv kubectl /usr/local/bin

Check the version of kubectl.

kubectl version --output=yaml

Step 7: Install eksctl

Execute the command to download kubectl.

curl --silent --location "https://github.com/weaveworks/eksctl/releases/latest/download/eksctl_$(uname -s)_amd64.tar.gz" | tar xz -C /tmp

Move eksctl to /usr/local/bin folder.

sudo mv /tmp/eksctl /usr/local/bin

Check the version of eksctl.

eksctl version

You should see the version

Step 8: Create IAM Role for eksctl

You need to create an IAM role and attach it to your “KubernetesServer” EC2 instance.

To do that you need to find EC2 in the search box.

Choose EC2 Virtual Server by clicking the link https://us-east-1.console.aws.amazon.com/ec2/.

Go to IAM Dashboard → Roles.

Click the button “Create role” on the IAM roles web page.

Then choose “AWS service” , “EC2”. And the click “Next” button.

Then, find “AmazonEC2FullAccess”, “AmazonEC2FullAccess“, “IAMFullAccess“, “AWSCloudFormationFullAccess“ in the search box and then click the “Add permissions” button.

And then click the “Next” button.

Then type “Eksctl_Role” into “Role name” input.

And the click “Create role” button.

The role is created finally.

Step 9: Connect IAM Role with eksctl

Go to the AWS EC2 instance web page. Choose “KuberbetesServer”. Then click “Actions” → “Security” → “Modify IAM Role”.

Choose “Eksctl_Role” and then click the “Update IAM role” button.

Now your IAM Role is connected with your “EKS_Server” and eksctl tool.

Step 10: Create eksctl cluster

Now, it's time to set up your EKS cluster.

To achieve this, follow these steps:

1. Modify the following command with your specific information.

eksctl create cluster --name cluster-name  \
--region region-name \
--node-type instance-type \
--nodes-min 2 \
--nodes-max 2 \ 
--zones <AZ-1>,<AZ-2>

For example, in my case, it looks like this.

eksctl create cluster --name zufarexplainedit  \
--region eu-north-1 \
--node-type t3.micro

2. Execute the modified command and patiently await the completion of the cluster creation process. You will notice that the EKS cluster status is indicated as "creating" on the AWS CloudFormation web page.

The cluster creation procedure typically takes around 20 minutes. Once completed, the terminal will display the outcome of the process.

Furthermore, you can verify the successful EKS cluster creation status on the AWS CloudFormation web page.

Step 11: Create Kubernetes Deployment yaml file

Now, as Kubernetes cluster, eksctl, kubectl are installed and configured, you can create a Kubernetes Deployment yaml file.

You can do that by executing the following command.

touch hello-app-deployment.yaml

Then, edit this file by executing the following command.

vi hello-app-deployment.yaml

Add this content to the hello-app-deployment.yaml.

apiVersion: apps/v1 
kind: Deployment
metadata:
  name: zufarexplainedit-hello-app
  labels: 
     app: hello-app

spec:
  replicas: 2 
  selector:
    matchLabels:
      app: hello-app

  template:
    metadata:
      labels:
        app: hello-app
    spec:
      containers:
      - name: hello-app
        image: zufarexplainedit/hello
        imagePullPolicy: Always
        ports:
        - containerPort: 8080
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1

Now hello-app-deployment.yaml is created and ready to use.

Step 12: Create Kubernetes Service yaml file

As Kubernetes cluster, eksctl, kubectl are installed and configured, you can create Kubernetes Service yaml file.

To do that you need to create a Kubernetes Service yaml file by executing the following command.

touch hello-app-service.yaml

Then, edit this file by executing the following command.

vi hello-app-service.yaml

Add this content to the hello-app-deployment.yaml.

apiVersion: v1
kind: Service
metadata:
  name: zufarexplainedit-hello-app-service
  labels:
    app: hello-app 
spec:
  selector:
    app: hello-app 

  ports:
    - port: 8080
      targetPort: 8080

  type: LoadBalancer

Now hello-app-service.yaml is created and ready to use.

Step 13: Test Kubernetes cluster using kubectl

With your Kubernetes EKS cluster successfully installed, and configured, and your Kubernetes service and deployment files ready, it's time to put things to the test using kubectl commands.

1. Apply Deployment.

   Use the following command to apply the deployment configuration.

kubectl apply -f hello-app-deployment.yaml

This will create a deployment with the specified number of replicas and a rolling update strategy, ensuring your application's availability and manageability.

2. Apply Service.

Next, apply the service configuration.

kubectl apply -f hello-app-service.yaml

This will set up a LoadBalancer type service, exposing your application to the internet.

Note that it might take a short while for the LoadBalancer to be provisioned and acquire an external IP address.

3. Check LoadBalancer Status.

   Monitor the status of your service using.

kubectl get service zufarexplainedit-hello-app-service

When an external IP is assigned, you're almost ready to access your application.

4. Access Your Application.

   Using a web browser, enter the assigned external IP address followed by :8080. After a brief moment, the page will load, displaying the "HelloWorld" message. Keep in mind that the initial loading might take a few seconds.

kubectl delete deployments --all

kubectl delete pods --all

kubectl delete services --all

eksctl delete cluster --name {your cluster name} --region {your region name} 

eksctl delete cluster --name zufarexplainedit --region eu-north-1

Step 14: Add and configure a new user in “KubernetesServer” AWS EC2 Virtual Server instance

Now let’s add a new ansible-admin user to “KubernetesServer” AWS EC2 Virtual Server instance.

To do that use this command.

sudo useradd ansible-admin

Then, set the password for ansible-admin user.

sudo passwd ansible-admin

Also, you need to configure user privileges by editing the sudoers file.

sudo visudo

Add “ansible-admin ALL=(ALL) ALL” to this sudoers file.

Also, you need to edit /etc/ssh/sshd_config file to enable PasswordAuthentication.

sudo vi /etc/ssh/sshd_config

Then you need to reload the service to make these changes.

sudo service sshd reload

As a result of executing this command, you will see:

sudo su - ansible-admin

Step 15: Generate key in an AWS EC2 Virtual Server instance

You are planning to manage remote servers such as K8s EC2 virtual server instance further in this article. That is why you need to set up SSH keys.

ssh-keygen

As a result of executing this command, you will see:

Now SSH keys are generated and ready to use.

Step 16: Configure Passwordless SSH authentication to localhost for Ansible

Ansible is designed for automating tasks on remote servers. Passwordless SSH authentication empowers Ansible to connect to those servers without the need for manual password entry.

Execute this command to create a secure connection from your computer to another computer (like the one at IP address 172.31.34.41), using the ansible-admin user's SSH key.

sudo ssh-copy-id -i /home/{your user name}/.ssh/id_rsa.pub {your user name}@{your host address}

In my case, it looks like this.

sudo ssh-copy-id -i /home/ansible-admin/.ssh/id_rsa.pub ansible-admin@172.31.34.41

Now you can see “Number of key(s) added: 1”. It means that the passwordless SSH authentication installation was successfully completed.

Step 17: Configure Ansible hosts in AnsibleServer EC2 instance

When you run an Ansible playbook, you specify the hosts it should run on. In this step you need to specify KubernetesServer EC2 instance host. To do that you need to repeat the same steps which you passed in “[Module 6]: Ansible”.

Let’s find out the KubernetesServer EC2 instance host by executing the following command.

sudo ifconfig

After you find the KubernetesServer EC2 instance host, you can add it to the Ansible hosts file by executing the following command.

sudo vi /etc/ansible/hosts

You can also add “[kubernetes]” as a reference

Step 18: Create a new Ansible playbook for Kubernetes tasks

Now that Kubernetes is all setup and good to go, you can make a new Ansible playbook with Kubernetes tasks for your pipeline. This playbook will let Ansible run your app on the Kubernetes cluster with kubectl commands.

Here's how you can do it:

1. Start by creating a new Ansible playbook file. Just use this command.

touch kubernetes-hello-app.yml

2. Then, edit the newly made hello-app.yml file. Open it up for editing with this command.

vi kubernetes-hello-app.yml

3. Inside the file, type in the following:

---
- hosts: kubernetes

  tasks:
    - name: deploy regapp on kubernetes
      command: kubectl apply -f hello-app-deployment.yaml

    - name: create service for regapp
      command: kubectl apply -f hello-app-service.yaml

    - name: update deployment with new pods if image updated in docker hub
      command: kubectl rollout restart deployment.apps/zufarexplainedit-hello-app

The Ansible playbook for Kubernetes tasks is ready to use.

Step 19: Integrate a new Ansible playbook for Kubernetes tasks with Jenkins

Now that Kubernetes, Ansible, and Ansible playbook for Kubernetes tasks are all set up and good to go, you can integrate it with Jenkins.

1. Go to JenkinsServer → Jenkins dashboard → New Item.

2. Create new Jenkins Freestyle project with the name “CD-Job”.

3. Click “OK” button.

4. Go to “Post-build Actions” section.

5. Click the “Add post-build action” button.

6. Choose “Send build artifacts over SSH” option.

7. Choose “AnsibleServer” as SSH Server.

8. Add this command to “exec command” input.

sudo -u ansible-admin ansible-playbook /opt/docker/kubernetes-hello-app.yml

9. Click “Apply” and “Save” buttons.

10. Go to Jenkins dashboard → “CI_CD_Pipeline” → Configure → “Post-build Actions” section.

11. Click the “Add post-build action” button.

12. Choose “Build other projects” option.

13. Go to “Build other projects” section.

14. Choose “Trigger only if build is stable” option.

15. Add “CD-Job” to “Project to build” input.

16. Click “Apply” and “Save” buttons.

Now you can consider that the pipeline is completely finished and ready to use.

Step 20: Testing the Final Pipeline Version

Now is the time to put the final pipeline version to the test.

Navigate to Jenkins → Jenkins dashboard → "CI_CD_Pipeline".

Click the "Build Now" button.

To see the results, review the build console logs.

You will notice that the "CD-Job" was triggered in the build console logs, and the final status is marked as SUCCESS.

4

Moreover, you can head to Dockerhub to confirm the addition of the new Docker image.

And finally, you can access your application using a web browser. Enter the assigned external IP address followed by ":8080". After a brief moment, the page will load, showing the "HelloWorld" message.

Conclusion

Well done on setting up this modern CI/CD pipeline!

You've done an awesome job, and you're a real hero!

Thanks for all your effort!

About the author

Zufar Sunagatov is an experienced senior software engineer who is passionate about designing modern software systems.

• Developed high-performance distributed systems using Java, Kotlin, AWS, Docker, and Kubernetes for companies like Citi (London), MTS (Moscow) and others (you can follow Zufar's LinkedIn profile for more information).
• Founded Ice Latte, an open-source online marketplace from scratch (you can join Zufar’s team and contribute to his project on GitHub: https://github.com/Sunagatov/Online-Store).
• Established the ZufarExplainedIT community to share his knowledge and experience with others (you can follow Zufar's IT Telegram community: https://t.me/zufarexplained).
• Mentored for over 3000 minutes and conducted 60 sessions on ADPlist, nurturing aspiring talents (you can get mentored by Zufar on ADPlist).
• Engaged audiences as a speaker at conferences and IT YouTube channels, sharing invaluable insights (examples of his YouTube videos include: “Тестовое собеседование Java разработчика #27 - Зуфар Сунагатов”, “Aspiring Speakers Lunchtime Lightning Talks May 28th”).
• Authored highly popular IT articles with 7000+ views each (examples of his articles are: “Microservice Architecture Patterns Part 1: Decomposition Patterns”, “Что значит «вариативный»? Объясняем простыми словами”).