Your CI/CD pipeline on AWS - Part 3 🚀 ☁

On your journey of making a CI/CD pipeline on AWS with these tools, you completed AWS CodeCommit & CodeBuild.

Next few days you'll learn these tools/services:

• CodeDeploy

• CodePipeline

• S3

What is CodeDeploy?

AWS CodeDeploy is a deployment service that automates application deployments to Amazon EC2 instances, on-premises instances, serverless Lambda functions, or Amazon ECS services.

CodeDeploy can deploy application content that runs on a server and is stored in Amazon S3 buckets, GitHub repositories, or Bitbucket repositories. CodeDeploy can also deploy a serverless Lambda function. You do not need to make changes to your existing code before you can use CodeDeploy.

Task 1:

-> Read about Appspec.yaml file for CodeDeploy.

The AppSpec file provides an easy way to specify deployment instructions for AWS CodeDeploy in a declarative YAML format. It allows you to customize the deployment process to meet the specific needs of your application.

-> Deploy index.html file on EC2 machine using nginx

Please refer day 50 and day 51 for better understandings. Here is the link for Day 50 and Part 51.

• Create an instance or restart the previous one.

• Now, let's create a CodeDeploy application. In AWS Console navigate to the CodeDeploy service.

• Click on "Create application" give it a name and select EC2/On-Premises as a compute platform.

• Before creating a deployment group, we have to create an IAM role and give all the necessary permissions to it.

• Update the Trust relationship in order to grant AWS CodeDeploy access to your target instances.

    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Effect": "Allow",
                "Principal": {
                    "Service": "codedeploy.amazonaws.com"
                },
                "Action": "sts:AssumeRole"
            }
        ]
    }

• Now, let's create a deployment group, in the CodeDeply application click on "Create deployment group" and give it a name.

• Click on "Create deployment group".

• Now we need to install the CodeDeploy agent on the server for which we need to write a script file with all the dependencies.

#!/bin/bash 

# This script installs the CodeDeploy agent and its prerequisites on Ubuntu 22.04.  

# Update package list
sudo apt-get update 

# Install Ruby and its dependencies
sudo apt-get install ruby-full ruby-webrick wget -y 

# Change to temporary directory
cd /tmp 

# Download the CodeDeploy agent package
wget https://aws-codedeploy-us-east-1.s3.us-east-1.amazonaws.com/releases/codedeploy-agent_1.3.2-1902_all.deb 

# Create a directory to extract the package contents
mkdir codedeploy-agent_1.3.2-1902_ubuntu22 

# Extract the package contents
dpkg-deb -R codedeploy-agent_1.3.2-1902_all.deb codedeploy-agent_1.3.2-1902_ubuntu22 

# Update the package dependencies to use Ruby 3.0
sed 's/Depends:.*/Depends:ruby3.0/' -i ./codedeploy-agent_1.3.2-1902_ubuntu22/DEBIAN/control 

# Repackage the updated package
dpkg-deb -b codedeploy-agent_1.3.2-1902_ubuntu22/ 

# Install the updated package
sudo dpkg -i codedeploy-agent_1.3.2-1902_ubuntu22.deb 

# List all systemd units that contain "codedeploy" in their name
systemctl list-units --type=service | grep codedeploy 

# Check the status of the CodeDeploy agent service
sudo service codedeploy-agent status

• Let's run this script.

Task 2: Add appspec.yaml file to CodeCommit Repository and complete the deployment process.

• AppSpec file is required to create a bridge between the AWS CodeDeploy and EC2 instance. Let's create one...

version: 0.0               #specifies the version number of the file format.
os: linux                  #specifies the operating system to be used.
files:                     #is an array of files to be copied from the source to the destination directory.
  - source: /               #specifies the source directory.
destination: /var/www/html #specifies the destination directory where the files will be copied to.
  hooks:                   #is an array of scripts to be executed at different points during the deployment process.
    AfterInstall:          #specifies a script to be executed after the installation of the application.
      - location: scripts/install_nginx.sh #specifies the location of the script file to be executed
        timeout: 300       #specifies the maximum amount of time in seconds that the script can run for.
        runas: root        #specifies the user that the script should be run as.
    ApplicationStart:      #specifies a script to be executed after the application has started.
      - location: scripts/start_nginx.sh
        timeout: 300
        runas: root

• Now we have to create 2 scripts for installing nginx and starting nginx.

• install_nginx.sh

#!/bin/bash

sudo apt-get update && sudo apt-get install -y nginx

• start_nginx.sh

#!/bin/bash

sudo systemctl start nginx
sudo systemctl enable nginx

• We also have to change the buildspec.yaml file so that the CodeBuild will build the appspec.yml file and transfer the artifact to S3 bucket.

version: 0.2

phases:
  install:
    commands:
      - echo Installing NGINX - echo apt-get install NGINX
      - sudo apt-get update
      - sudo apt-get install nginx -y
  build:
    commands:
      - echo Build started on date
      - cp index.html /var/www/html
  post_build:
    commands:
      - echo Configuring NGINX
artifacts:
    files:
      - "**/*"

• Let's push all the changes to the CodeCommit repository.

• You can view the new code files in the CodeCommit repository.

• Let's edit the build, select the artifacts and update it after that start the build.

• Now, We have to Create a role for giving access to the EC2 instance with all the necessary permission policies as shown below.

• Now, navigate to the instance and modify the IAM role. Select the IAM role created above.

• Now create a deployment in the deployment group that we made previously.

• Click on "Create deployment"

• Provide the S3 artifactory details. This will pull the code at the time of CodeDeploy. Then create the deployment.

• Click on "Create deployment"

• Restart the codedeploy-agent in the EC2 instance.

• Once the codedeploy-agent restarted, the deployment will get completed successfully.

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