lab1-aws-basics

Lab 1 - AWS Basics

The goal for this lab is to move the Spring Petclinic application to a simple but highly effective web architecture on AWS leveraging some of our original lower level services. This approach will be familiar to developers deploying applications in an on premises environment, consisting of a load balancer and an autoscaling fleet of web servers.

Prerequisites

Make sure you have completed lab0-getting-started

Steps

Provision the devops pipeline

1. Navigate to your local clone of the lab project from github.

2. Changed into the lab 1 directory

   cd lab1-aws-basics
   

3. Open this folder in your favourite IDE or whenever we say to edit a file in subsequent steps feel free to use Vim or another editor of choice.

4. Edit the file ops-pipeline/src/main/java/software/amazon/samples/PipelineStack At the top of this file is a collection of constants that you need to update to reflect the notes you have made during the getting started lab. In particular you need to update:

   1. The regional code build cache bucket name
   2. The github secret name and key
   3. The github owner details Take the time to review the rest of the file. This is where we are defining the CI/CD pipeline that will be used to incrementally build and update our application plus its environment on every commit.

5. Build the project with

   mvn package
   

6. Commit the changes and push the commit back to your remote copy in github with:

   git commit -am "localised lab1 pipeline configuration"
   

   and

   git push origin master
   

7. Change into the ops-pipeline directory

   cd ops-pipeline
   

8. Do a test generation of the cloudformation template for the pipeline by running:

   cdk synth
   

   This should print a cloudformation template to std out that you can review and correlate with the PipelineStack.java file that you edited earlier.

9. Deploy our pipeline cloudformation stack using the cdk cli by running:

   cdk deploy
   

10. If everything lines up then this will create a cloudformation stack that provisions an AWS CodePipeline pipeline and a AWS CodeBuild build project. Once complete the pipeline will do an intial run using the latest commit in your repository on github. The pipeline will in turn use the cdk cli to provision the environment for this project which is defined in <project>/ops-environment/src/main/java/software/amazon/samples/InfrastructureStack.java. At the end of the pipeline run you should have another cloudformation stack for petclinic environment which you view in the Cloudformation service in the AWS Console. If you click on the outputs tab for this stack you can see the URL that our application should now be live on. Make a copy of this url and open it in a web browser. If all is successful then you should see the Petclinic welcome page. If not click on the pipeline in the AWS CodePipeline service in the console and look at any failed steps and their associated logs for clues on where things might have been misconfigured.

Test your pipeline by making a change

Lets rollout both a cosmetic change to the petclinic application and a change to the environment in a single commit.

2. Edit <project>/ops-environment/src/main/java/software/amazon/samples/InfrastructureStack.java and change the instance type size in our autoscaling group to InstanceSize.Micro.

3. Edit <project>/spring-petclinic/src/main/resources/messages/messages.properties and change the welcome message from 'Welcome' to 'Hello'

4. Navigate back to the lab1 parent folder if not already there. Commit and push the current changes with

   git commit -am "Optimising instance type and fixing greeting"
   

   and

   git push origin master
   

5. Watch the pipeline process this change in the AWS CodePipeline console page. Once the pipeline completes it will still take some time for the autoscaling group to spin up a new instance and tear down the old one. You can watch this process in action on the Amazon EC2 console page. Once the new instance is live you should be able to refresh the petclinic url in your browser and see the changed greeting message.

Key Learnings

TODO