Setting up a CI/CD pipeline by integrating Jenkins with AWS CodeBuild and AWS CodeDeploy

The functioning pipeline creates a fully managed build service that compiles your source code. It then produces code artifacts that can be used by CodeDeploy to deploy to your production environment automatically.

The deployment workflow starts by placing the application code on the GitHub repository. To automate this scenario, I added source code management to the Jenkins project under the Source Code section. I chose the GitHub option, which by design clones a copy from the GitHub repo content in the Jenkins local workspace directory.

In the second step of my automation procedure, I enabled a trigger for the Jenkins server using an “Poll SCM” option. This option makes Jenkins check the configured repository for any new commits/code changes with a specified frequency. In this testing scenario, I configured the trigger to perform every two minutes. The automated Jenkins deployment process works as follows:

1. Jenkins checks for any new changes on GitHub every two minutes.

2. Change determination:

   a) If Jenkins finds no changes, Jenkins exits the procedure.

   b) If it does find changes, Jenkins clones all the files from the GitHub repository to the Jenkins server workspace directory.

3. The File Operation plugin deletes all the files cloned from GitHub. This keeps the Jenkins workspace directory clean.

4. The AWS CodeBuild plugin zips the files and sends them to a predefined Amazon S3 bucket location then initiates the CodeBuild project, which obtains the code from the S3 bucket. The project then creates the output artifact zip file, and stores that file again on the S3 bucket.

5. The HTTP Request plugin downloads the CodeBuild output artifacts from the S3 bucket.

I edited the S3 bucket policy to allow access from the Jenkins server IP address.

{
  "Version": "2012-10-17",
  "Id": "S3PolicyId1",
  "Statement": [
    {
      "Sid": "IPAllow",
      "Effect": "Allow",
      "Principal": "*",
      "Action": "s3:*",
      "Resource": "arn:aws:s3:::examplebucket/*",
      "Condition": {
         "IpAddress": {"aws:SourceIp": "x.x.x.x/x"},  <--- IP of the Jenkins server
      } 
    } 
  ]
}

This policy enables the HTTP request plugin to access the S3 bucket. This plugin doesn’t use the IAM instance profile or the AWS access keys (access key ID and secret access key).

6. The output artifact is a compressed ZIP file. The CodeDeploy plugin by design requires the files to be unzipped to zip them and send them over to the S3 bucket for the CodeDeploy deployment. For that, I used the File Operation plugin to perform the following:

   a) Unzip the CodeBuild zipped artifact output in the Jenkins root workspace directory. At this point, the workspace directory should include the original zip file downloaded from the S3 bucket from Step 5 and the files extracted from this archive.

   b) Delete the original .zip file, and leave only the source bundle contents for the deployment.

7. The CodeDeploy plugin selects and zips all workspace directory files. This plugin uses the CodeDeploy application name, deployment group name, and deployment configurations that you configured to initiate a new CodeDeploy deployment. The CodeDeploy plugin then uploads the newly zipped file according to the S3 bucket location provided to CodeDeploy as a source code for its new deployment operation.