Build a Tomcat Runtime on Docker: A Complete Step‑by‑Step Tutorial

Docker provides an automated way to deploy applications in lightweight containers, separating production and development environments. This tutorial shows how to create a Tomcat runtime inside Docker on an Ubuntu 13.10 server.

Environment

The host is a 64‑bit Ubuntu 13.10 server running in VMware Workstation.

Install Docker (0.7)

sudo apt-get update

sudo apt-get install linux-image-extra-$(uname -r)

sudo sh -c "wget -qO- https://get.docker.io/gpg | apt-key add -"

sudo sh -c "echo deb http://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list"

sudo apt-get update

sudo apt-get install lxc-docker

sudo docker version

# verify installation

Remove the need for sudo

sudo groupadd docker

sudo gpasswd -a yongboy docker

# replace yongboy with your login name

sudo service docker restart

docker version

# should work without sudo

Pull and Run a Tutorial Image

docker pull learn/tutorial

docker run learn/tutorial /bin/echo hello world

docker run -i -t learn/tutorial /bin/bash

# enter interactive shell

Inside the container you see a prompt like root@51774a81beb3:/#, confirming you are in the interactive environment.

Install SSH Server in the Container

apt-get update

apt-get install openssh-server

which sshd

# should return

/usr/sbin/sshd

mkdir /var/run/sshd

passwd

# set a password (e.g., 123456) for SSH login

exit

Commit the Container as a New Image

docker ps -l

# obtain the container ID, e.g.,

51774a81beb3

docker commit 51774a81beb3 learn/tutorial

Run the Image with Port Mappings

docker run -d -p 22 -p 80:8080 learn/tutorial /usr/sbin/sshd -D

This starts the container in the background, exposing SSH on a random host port (e.g., 49154) and mapping the container’s Tomcat port 8080 to host port 80.

Verify and Access the Services

docker ps

# shows the running container and port mappings ssh [email protected] -p 49154 # SSH into the container

Install Oracle JDK 7 and Tomcat 7.0.47 Inside the Container

apt-get install python-software-properties

add-apt-repository ppa:webupd8team/java

apt-get update

apt-get install -y wget

apt-get install oracle-java7-installer

java -version

wget http://mirror.bit.edu.cn/apache/tomcat/tomcat-7/v7.0.47/bin/apache-tomcat-7.0.47.tar.gz

tar xvf apache-tomcat-7.0.47.tar.gz

cd apache-tomcat-7.0.47

bin/startup.sh

Tomcat runs on port 8080 inside the container; because of the -p 80:8080 mapping, it is reachable on the host’s port 80. Test with: curl http://192.168.190.131 Or open a browser and navigate to the host IP.

Conclusion

Using Docker to set up a Tomcat runtime is straightforward and demonstrates a basic PaaS scenario. Future articles will cover automated image building with Dockerfiles and deeper insights into Docker’s architecture and mechanisms.