Wildfly Cluster in Docker

This is a short example of Wildfly running in two docker container and create a cluster. The container are managed by a compose file.

To start the example you have to type:

docker-compose up

Docker will pull the current wildfly image and start two docker container and create a cluster with both. You can see that the cluster is working when the following part is shown in the log:

INFO [org.infinispan.CLUSTER] (MSC service thread 1-4) ISPN000094: Received new cluster view for channel ejb: [wildfly_2_test|1] (2) [wildfly_2_test, wildfly_1_test]

You can reach the example war under:

• http://127.0.0.1:8080/helloworld/HelloWorld
• http://127.0.0.1:8080/helloworld/HelloWorld

Requirements

• docker
• docker-compose

Dockerfile

• -Djboss.node.name=${WILDFLY_NAME}
  • The wildfly name is specified with that there are no name conflicts in the cluster.
• -Djava.net.preferIPv4Stack=true
  • infinispan has to use the ipv4 stack to comunicate over the 230.0.0.4 address (default)
• -Djgroups.bind_addr=$(hostname -i)
  • important to bind jgoup to the local IP of the container
  • if you forget this parameter, jgroup use 127.0.0.1 --> this will not work if you are trying to create a cluster over different machines
• -Djboss.messaging.cluster.password=${CLUSTER_PW}
  • you have to change the standard password, if not, JBoss will throw an exception and you cannot use the distributed cache

docker-compose.yaml

The docker-compose.yaml file will provide the arguments for the container and will build the image with the current dockerfile. It also defines the network, in which the two wildly are operating.