Spring Boot Docker Demo

Medium Article

To accompany this project, a detailed Medium article has been created. The article covers various aspects of Dockerizing a Spring Boot application and offers a step-by-step guide. You can find the article at the following link:

Briding the memory gap between your device and the cloud

Allows you to quickly play around with memory consumption

Usage

Build and compile the application

mvn clean install

Run the spring boot application

mvn spring-boot:run

Build the docker image

Either using docker

mvn clean install
docker build -t ixor/memory-demo .

or via the JIB maven plugin

mvn compile jib:dockerBuild

Launch docker compose

docker-compose up -d

Take up memory

We have provided an endpoint allowing you to easily force the app to consume an amount of memory (in megabytes) and retain it. This allows for easy testing memory consumption. Everytime you reserve some memory you will get an ID for that block of memory that you can later use to release using the releaseMemory endpoint

curl  http://localhost:8080/memory/take/100

Allocated 100 megabytes of memory with ID 4 

Releasing memory

Release the memory by using the ID returned by the takeMemory endpoint

curl  http://localhost:8080/memory/release/4

Released memory with ID 4

Using Visual VM

When you are running yout application on a remote server, even with the following JAVA_TOOL_OPTIONS exposed, you might still run into difficulties connecting to it via VisualVM

export JAVA_TOOL_OPTIONS="-Dcom.sun.management.jmxremote.port=9010 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.rmi.port=9010 -Dcom.sun.management.jmxremote.host=0.0.0.0 -Djava.rmi.server.hostname=0.0.0.0"

In that case you need to setup a tunnel (replace 1.2.3.4 with your public ip address)

ssh -i ~/.ssh/ec2-test-keypair.pem [email protected] -N -L 0.0.0.0:9010:127.0.0.1:9010

That way you will be able to hook up VisualVM to it using 127.0.0.1:9010