Go back to the source code, open the file src/components/Calculator.js. Change line 137 from Version 1.0 to 2.0.
Push the code to the repo:
Run git add ..
Run git commit -m "Update to 2.0" to commit the code locally.
Run git push origin master to push the code to the repo on CodeCommit.
Go back to the pipeline console, observe the pipeline will be triggered and run the source Update to 2.0, and the Deploy stage is successfully run.
Go to the ECS console, view the tasks of the FCJ_Cluser cluster, we will see 3 new tasks Running, this is the Green environment, while the old 3 tasks are the Blue environment.
Access CodeDeploy, select Deployments from the left menu, we will see the deployment of the application is In progress…. Click to view details.
The image below shows that traffic sent to the DNS name of FCJ_ALB is being switched from Blue environment (90%) to Green environment (10%), meaning switching from application Version 1.0 to 2.0.
We have configured this to be 10% every minute (step 5 of section 6.4).
Open another tab, or another browser.
Access DNS name of FCJ_ALB (step 17 of section 6.4).
Try hard refresh (Ctrl + R) a few times.
You will see that sometimes you receive Version 1.0, sometimes it is Version 2.0.
The experiment will be clearer when more % of traffic is switched from Blue environment to Green environment.
6 tasks, 3 tasks for each side Blue and Green, will coexist parallelly until the deployment process is successful.
You can distinguish old and new by viewing the version of the task definition. As in the image, the new is 10 and the old is 9.
This image shows that all traffic has been switched from Blue environment (0%) to Green environment (100%). From here, the current Blue environment will be terminated, the current Green environment will be promoted to the new Blue environment.
Step 3 of the deployment will wait 15 minutes (step 13 of section 6.4) to ensure system stability, if anything causes the deployment to fail, the system will automatically roll back. Otherwise, if everything is stable, the current Green environment will be terminated.
3 tasks of old Blue environment (task definition 9) have been terminated and 3 new tasks (task definition 10) will be promoted to the new Blue environment, serving 100% of user traffic.
All deployment steps have been successfully completed.
Confirm the pipeline has run source Update to 2.0 successfully.
So you have completed a Blue/Green deployment pipeline using AWS CodePipeline.
