Update the application with latest change and validating image tags

• Editing the application source in Cloud9
• Committing and pushing the change to CodeCommit
• Starting a build in CodeBuild that builds and pushes an image to ECR
• Updating the ECS service to use the new task definition revision
• Verifying the running application and tracing the image back to the commit hash

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1) Edit the application in Cloud9

• In the Cloud9 editor open templates/login.html.
• Replace the existing heading (for example LOGIN) with the new heading LOGIN V2 and save the file.

<h2 class="login-title">LOGIN</h2>
<!-- updated to -->
<h2 class="login-title">LOGIN V2</h2>

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2) Commit and push the change from the Cloud9 terminal

cd ~/environment/aws/aws-microservice-project

# Check status
git status

# Stage all changes and commit
git add .
git commit -m "application change: update login heading to LOGIN V2"

# Push to remote (CodeCommit)
git push origin master

Counting objects: 100% (177/177), done.
Writing objects: 100% (63/63), 194.80 KiB, done.
To https://git-codecommit.eu-central-1.amazonaws.com/v1/repos/aws-microservice-project
   eb72454..3257666  master -> master

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3) Start a new build in AWS CodeBuild

• In the AWS Console go to CodeBuild → Build projects.
• Select your project and click Start build.
• Monitor the build logs. The buildspec should perform steps such as:
  • Checking aws --version
  • Building the Docker image
  • Tagging the image (including the Git commit hash)
  • Pushing the image to the ECR repository

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4) Update the Amazon ECS service to use the new task definition

• In the AWS Console open ECS → Task Definitions and verify that CodeBuild (or your pipeline) registered a new task definition revision.
• Navigate to Clusters → <your production cluster> → Services → <your service> → Update.
• From the task definition drop-down, choose the new revision (for example, revision 3), proceed through the update flow and click Update.
• ECS will perform a rolling deployment: old tasks will be replaced by tasks using the new task definition.

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5) Monitor the deployment and inspect the running tasks

• The service will show a deployment in progress. Wait until the deployment shows primary status 100% and all tasks are healthy.
• Under the cluster Tasks tab you should see the recently launched task(s) and timestamps matching your deployment.

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Inspect the task and application

• Select a task, open the container details to view the image URI and network bindings.
• Use the network binding URL (public IP / load balancer target) to open the application and confirm the UI change (the login heading should now show LOGIN V2).

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6) Trace the running image back to the Git commit

• In the ECS task details note the container image URI. The image tag commonly contains the Git commit hash (for example 3257666).
• In the AWS Console open ECR → <your repository> and find the image tag used by your running task.
• Copy that commit hash and open CodeCommit → <your repository> → Commits.
• Search or filter by the commit hash to find the exact commit that introduced the change.

<h2 class="login-title">LOGIN</h2>
<h2 class="login-title">LOGIN V2</h2>

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Quick reference — typical commands and locations

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Summary

• Edited templates/login.html in Cloud9 and pushed the change to AWS CodeCommit.
• Started CodeBuild which built and pushed a Docker image to Amazon ECR (image tagged with the commit hash).
• Updated the ECS service to a new task definition revision and validated the UI change (LOGIN V2).
• Traced the running container image back to the specific CodeCommit commit for full traceability.

• AWS Cloud9
• AWS CodeCommit
• AWS CodeBuild
• Amazon ECR
• Amazon ECS