How to run a wildfly server inside docker

Before we begin you must configure docker, I am using Ubuntu so I followed the guide here: https://docs.docker.com/engine/installation/linux/ubuntulinux/. Choose the appropriate OS that applies to you.

Let's do this in sequence:

1. Checkout and compile the very basic javaee war from https://github.com/czetsuya/hello-javaee.
2. In Ubuntu create a new folder: wildfly-hello:
   >mkdir wildfly-hello
3. Copy hello-javaee.war inside wildfly-hello.
4. Create a Dockerfile and insert the lines below inside the same folder.
   
   

   from jboss/wildfly
   run /opt/jboss/wildfly/bin/add-user.sh admin admin@1234 --silent
   add hello-javaee.war /opt/jboss/wildfly/standalone/deployments/
   cmd ["/opt/jboss/wildfly/bin/standalone.sh", "-b", "0.0.0.0", "-bmanagement", "0.0.0.0"]

5. Inside the wildfly-hello folder build the Dockerfile.
   >docker build -it wildfly-hello .
6. Run the docker image
   >docker run wildfly-hello
7. Get the ip address of the container by:
   >docker ps - to get the container id
   >docker inspect -f '{{ .NetworkSettings.IPAddress }}' CONTAINER_ID
8. Now we should have the ip address of docker, we can now open wildfly in the browser.

What does the lines in step 3 means?
-from is a docker keyword use to import an image from docker hub hub.docker.com
-run is a command that runs an executable file, in this case we are adding a user with application management role
-add lets us add a file inside the container
-cmd tells the docker to execute this by default, when we execute docker run