Java 8 example application.

• Spring boot v2.3.8
• Java 8 (OpenJDK)
• Dependencies:
  • spring-boot-starter-actuator
  • spring-boot-starter-web
  • spring-boot-starter-test
  • micrometer-registry-prometheus
• Graceful shutdown
• Liveness&Readiness probes
• Actuator endpoints enabled:
  • health
  • info
  • env
  • loggers
  • metrics
  • prometheus
• Standardized, layered Dockerfile
• standardized configuration management:
  • configurations under src/main/resources/application.yaml
  • You can choose a profile using the environment variable ACTIVE_PROFILES.
• The container is run with the user app (UID 1000, GID 1000) to avoid the root user

The Dockerfile specifies how the image is created. This file creates a layered image, click here for more info. The base image is eclipse-temurin:8u342-b07-jre-focal.

Docker entrypoint bin/docker-entrypoint.sh.

Docker build command docker build -t <tag> .

Spring Boot Actuator enabled on src/main/resources/application.properties:

management.endpoints.web.exposure.include = health, info, env, loggers, metrics, prometheus, configprops

You can connect a MySQL database by activating the spring profile db. The environment variable is ACTIVE_PROFILES=db. In the default behaviour, no database is connected. You can also set other environment variables:

DB_URL default value localhost:3306

DB_USER default value user

DB_PASSWORD default value password

The application exposes the default context path /test-app/v1.

The class TestController exposes some test endpoints.

For example, you can get the instance id calling GET localhost:8080/test-app/v1/app/id

You can build this project with AWSCodeBuild. The configuration file under the root directory is buildspec.yml. This file builds the maven project and uploads a docker image to Elastic Container Registry.

Remember to define your Elastic Container Registry parameters AWS_DEFAULT_REGION,AWS_ACCOUNT_ID,AWS_DEFAULT_REGION,IMAGE_TAG.