#Lightweight Spring Boot Docker image based on Alpine + Docker Compose file

Features:

• Spring profiles
• Custom JAVA_OPTS
• Healthcheck
• Wrapper script that enables application to take PID 1 & receive SIGTERM signals
• Debug mode

This tag integrates an healthcheck feature to tell Docker how to check the status of the container. This feature simply executes an HTTP request to a given URL: ${SERVER_PROTOCOL}://localhost:${SERVER_PORT}/${HEALTHCHECK_CONTEXT}

Available environment variables

Name	Default	Description
DEBUG	false	Enable or disable debug mode
DEBUG_PORT	8000	Debug port
SPRING_PROFILES_ACTIVE	dev	Active Spring profiles
JAVA_OPTS		JAVA_OPTS
SERVER_PROTOCOL	http	Spring Boot application server protocol, picked by the healthcheck command to check the application status
SERVER_PORT	8080	Spring Boot application server port (server.port), picked by the healthcheck command to check the application status
HEALTHCHECK_CONTEXT	/	The context URL to check the application status, picked by the healthcheck command to check the application status

How to use ?

1. Simply extend your image from flopes/spring-boot-docker and set your application name as an environment variable:

   FROM flopes/spring-boot-docker:1.0
   
   ENV ARTIFACT_NAME my-spring-boot-application.jar
   

2. Copy your Spring Boot executable jar into an assets folder and build you image: docker build -t spring-boot-image .

3. Start your application:

   • Using Docker CLI

   • Using the provided docker-compose.yml in this repository: docker-compose up -d

Inject environment variables:

docker run -d -p 8080:8080 -e JAVA_OPTS=-Xms256m -Xmx512m spring-boot-image

Using Docker Compose

The docker-compose.yml file picks its configuration from the .env one.

Using this file, you can set the desired properties:

# Docker
IMAGE_NAME=spring-boot-docker
HEALTHCHECK_CONTEXT=/

# Application
SERVER_PROTOCOL=http
SERVER_PORT=8080
DEBUG_PORT=8000
SPRING_PROFILES_ACTIVE=dev
DEBUG=false
# -Dprop=... -Dparameter=...
JAVA_OPTS=

# Host
HOST_SERVER_PORT=8080
HOST_DEBUG_PORT=8000

Debug mode

To run the application in debug mode, simply set the DEBUG variable to true in the .env file.

Launch the application: docker-compose up -d

By default, the debug port used is the 8000.

Spring profile(s)

By default, the application will run with dev Spring profile

To run the application with a specific Spring profile, set the desired one in the .env file:

SPRING_PROFILES_ACTIVE=dev