Step 3: Create a CodeBuild Project

1. IAM Role for CodeBuild Create an IAM role "codebuild-role" with a policy allowing CodeBuild service to assume this role. Attaches the 'AWSCodeBuildDeveloperAccess' policy to this role, granting necessary permissions for CodeBuild operations

2. CodeBuild project

   Defines a CodeBuild project "ApplicationBuildProject" with specified configurations:
       service_role: Specifies the IAM role that CodeBuild will use.
       artifacts: Configures build artifacts to be stored in the S3 bucket created earlier.
       environment: Defines the build environment, including compute type, image, and environment variables.
       source: Specifies the source repository for the build, which is the CodeCommit repository created earlier.

Step 4: Create a CodeDeploy Application and Deployment Group

1. IAM Role for CodeDeploy Creates an IAM role for CodeDeploy with a trust policy allowing CodeDeploy service to assume this role. Attaches the 'AWSCodeDeployRole' policy to this role, granting necessary permissions for CodeDeploy operations.

2. CodeDeploy Application and Deployment Group Defines a CodeDeploy application named "ApplicationDeployApp" and a deployment group named "ApplicationDeploymentGroup" with specified configurations: service_role_arn: Specifies the IAM role that CodeDeploy will use. deployment_config_name: Sets the deployment configuration. auto_rollback_configuration: Enables automatic rollback on deployment failure. ec2_tag_set: Specifies EC2 instances by tags where the application will be deployed.

Step 5: Create a CodePipeline

1. IAM Role for CodePipeline Creates an IAM role for CodePipeline with a trust policy allowing CodePipeline service to assume this role. Attaches a policy with necessary permissions for CodePipeline operations, including interacting with various AWS services involved in the CI/CD process.

   Defines a CodePipeline named "ApplicationPipeline" with specified configurations:
   
       role_arn: Specifies the IAM role that CodePipeline will use.
   
       artifact_store: Configures the S3 bucket created earlier to store pipeline artifacts.
   
       stages: Defines pipeline stages, each containing actions to perform specific tasks such as source code retrieval, build, and deployment.
   
       Source Stage: Retrieves source code from the CodeCommit repository.
   
       Build Stage: Builds the application using CodeBuild.
   
       Deploy Stage: Deploys the application using CodeDeploy.