How to write a dockerfile for running a java application (*.war) in Apache tomcat webserver
I have a sample hello-world maven project in github hello-world
Maven is a build tool used to compile, test and package the application developed using Java programming language.
Run the mvn clean package command to compile and package the java application.
The hello-world.war file will be created in targets folder

I have already created a file Dockerfile and kept in root folder
From tomcat:8-jre8
COPY ./target/hello-world.war /usr/local/tomcat/webapps
In the FROM command we are taking tomcat:8-jre8 as a base image.
On top of that we are copying the hello-world.war file from target folder and keeping it in /usr/local/tomcat/webapps inside a container.
we no need to explicity define the CMD here, because CMD is already written in base docker image tomcat:8-jre8 to start the tomcat webserver.