docker

Docker and tomcat 8 in a few simple steps

Overview

The process flow of getting a docker container up and running Tomcat 8 with a hello world application.

Prerequisites

1. Build a hello world war file, use the git repo https://github.com/efsavage/hello-world-war

2. Install docker https://docs.docker.com/engine/installation/linux/ubuntulinux/

Steps

1. Build a docker image
2. Check the image
3. Run a docker container from the image
4. List the container
5. Attach to the running docker container to inspect details
6. Shutdown the container

Build a docker image

Create a directory called "docker" and copy the "hello world" war file and the "Dockerfile" in this directory.

On listing the contents of the directory "docker"

root@ubuntu:~# ls docker
Dockerfile  hello-world.war

To build the image using the Dockerfile run the below command.

Change the tag "thinktag/tomcat" to something else.

docker build -t 'thinktag/tomcat' docker/

Check the images

Run the below command to list the images

root@ubuntu:~# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
thinktag            tomcat              ac8bcb99503a        22 minutes ago      779.8 MB
ubuntu              14.04               b2f1fdd93175        3 days ago          188.4 MB

Run a docker container from the image.

To run a docker container using the created images

docker run -d -p 8080:8080 -p 8009:8009 thinktag:tomcat

List the containers.

To list the running containers

```shell

root@ubuntu:~# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                            NAMES
164e21a62c99        thinktag:tomcat     "/opt/tomcat/bin/cata"   25 minutes ago      Up 25 minutes       0.0.0.0:8009->8009/tcp, 0.0.0.0:8080->8080/tcp   gigantic_bhaskara

```

Attach to the running docker container to inspect details

You can attach to a running container for debugging

```shell

root@ubuntu:~# docker exec -it 164e21a62c99 /bin/bash
root@164e21a62c99:/opt/tomcat#

```

Shutdown the container

You can shutdown the container by shutting down tomcat.

```shell

root@ubuntu:~# docker exec -it 164e21a62c99 /bin/bash
root@164e21a62c99:/opt/tomcat# bin/shutdown.sh

```

References

https://github.com/cmoro-deusto/docker-tomcat8/blob/master/Dockerfile