[SAM][architecture] Give up lambda for PaimonGanyuSpringBootApp, use Elastic Beanstalk instead.

[binchoo]

As-is

Running a SpringBoot application on a lambda container is not optimal at all.
The aws-serverless-java-container module is trying the best to support SpringBoot apps on the lambda service, but it is not satisfying me.

Cons:

• DispatherServlet is not available.
• ArgumentResolvers, ViewResolvers are not usable.
• Cold start latency is terrible.

Pros:

• Easy to deploy.
• Easy to configure IAM Roles and IAM Policies.

[binchoo]

To-be

Let's use Elastic Beanstalk.

[binchoo]

Change Impact

The principle: "Keep single-jar deployment."

Java code base

• PaminGanyu> :application module
  • Resolve the timezone problem programmatically. (Don't make .ebextensions file. Keep the principle.)
  • Introduce a HealthCheckController to support ALB's health checking mechanisms.
  • Add a /health handler mapping.
  • application.properties> set server.port=5000 to customarily handle the proxied request from nginx.

What the doc says:

--HTTP(80)--> ALB --HTTP(80)--> ASG --HTTP(80)--> NGINX --HTTP(5000)--> SpringBootApp 

IAM

• Create an IAM Role that will be required by the paimonganyu-skill's instance profile.
  • DynamoDB CRUD policies attached.
  • SSM Parameter CRUD policies attached.

AWS Beanstalk

• Create an application named paimonganyu-skill.
• ALB Configurations
  
  Do not bother yourself to tell that a process is using the 5000 port, because NGINX transparently forwards requests from 80 to 5000.

AWS SAM template.yaml

• Commentify the PaimonGanyuSpringBootApp section in the original template.yaml.
• Write down a new template.yaml named paimonganyu-skill.yaml that configures the paimonganyu-skill application.
  • Consider multiple environments: prod and test.
• Create an API Gateway resource explictly, as the PaimonGanyuSpringBootApp.Properties.Events is gonna be removed.
• Create an IAM Role resource that I said before.

Makefile

• Define a workflow that builds & deploys a bootJar to the paimonganyu-skill beanstalk app.