java-spring

Demo Java-Spring App

This demo app uses Java and Spring-Boot. It can be deployed as a native app or containerized with Docker. It is deployed using Marathon.

Table of Contents

• Containerized
• Native
• Load Balancer

Containerized

Containerized Marathon apps will download the required Docker image from DockerHub (or a specified docker registry).

Deploy

dcos marathon app add examples/java-spring/java-spring-docker.json

Access

APP_ADDRESS=$(curl -s http://m1.dcos/marathon/v2/apps/java-spring-docker | \
  jq '.app.tasks[0].host + ":" + (.app.tasks[0].ports[0] | tostring)' -r)
curl http://${APP_ADDRESS}

Scale

Since the app is configured to be unique per node, one private agent node is required for each app instance.

dcos marathon app update java-spring-docker instances=3

Native

Running a native java app requires that the application jar and the Java JRE be installed on the agent nodes. Use DCOS_JAVA_ENABLED=true when deploying the agent nodes to install both automatically (requires the JRE to be downloaded to <repo>/build/jre-*-linux-x64.tgz).

Deploy

dcos marathon app add examples/java-spring/java-spring.json

Access

APP_ADDRESS=$(curl -s http://m1.dcos/marathon/v2/apps/java-spring | \
  jq '.app.tasks[0].host + ":" + (.app.tasks[0].ports[0] | tostring)' -r)
curl http://${APP_ADDRESS}

Scale

Since the app is configured to be unique per node, one private agent node is required for each app instance.

dcos marathon app update java-spring instances=3

Load Balancer

On production deployments of DC/OS, the private agent nodes are not usually externally accessible. So a load balancer (reverse proxy) is required in order to be able to access apps. One way to do that is with Marathon-LB.

Add Multiverse Package Repository

Marathon-LB is in the Multiverse repo. So the Multiverse must be added to the DC/OS CLI config.

See the DC/OS CLI docs on how to add the multiverse repo.

Deploy Marathon-LB

dcos package install marathon-lb --yes

Access Java-Spring App

Hit the load balanced endpoint multiple times to be proxied to different agent nodes.

curl http://spring.acme.org/

==OR==

LB_PORT=$(curl -s http://m1.dcos/marathon/v2/apps/java-spring-docker | \
  jq '.app.ports[0]' -r)
curl http://p1.dcos:${LB_PORT}/