Building a Tomcat Docker Image with a Custom Dockerfile

The article provides step‑by‑step instructions for building a Docker image that runs Apache Tomcat on a CentOS base.

First, the author shows the file layout on the host machine, including the Tomcat archive and JDK RPM:

-rw-r--r-- 1 root root   9122588 Nov 6 20:41 apache-tomcat-8.0.26.tar.gz

-rw-r--r-- 1 root root 102957056 Nov 6 20:57 jdk-8u45-linux-x64.rpm

Then the complete Dockerfile is presented:

FROM centos

MAINTAINER hahashen

RUN yum install wget -y

ADD jdk-8u45-linux-x64.rpm /usr/local/

ADD apache-tomcat-8.0.26.tar.gz /usr/local/

RUN cd /usr/local && rpm -vhi jdk-8u45-linux-x64.rpm

RUN mv /usr/local/apache-tomcat-8.0.26 /usr/local/tomcat

ENTRYPOINT /usr/local/tomcat/bin/startup.sh && tail -F /usr/local/tomcat/catalina.out

EXPOSE 8080

After saving the file, the image is built with: docker build -t="tomcat:v1" . The resulting image can be verified: docker images | grep tomcat And a container is started, mapping host port 8080 to the container:

docker run -itd -p 8080:8080 --name tomcat01 tomcat:v1 /bin/bash

Because the container needs to launch Tomcat, the ENTRYPOINT line runs the Tomcat startup script and tails the log so the container stays alive.

The author also notes that JDK environment variables could be added using the ENV instruction if desired.