This article describes how to deploy a JSP website using Docker, Apache Tomcat.
I found a way to make a minimal JSP web application from scratch, without any IDE. (ref: https://www.youtube.com/watch?v=JEBR_KJdzSk)
First, organize your working directory like this:
yourproject/
Dockerfile
webapp/
WEB-INF/
classes/
lib/
web.xml
index.jsp
Right now, just leave every folders and files empty. This is the skeleton of our Dockerized web application.
First, we should fill some content for our web application. Take your favorite editor and edit these files:
<web-app>
</web-app>It can be empty. Later, you can edit this file as you want.
<!doctype html>
<h1>It works!</h1>
<%
for (int i = 0; i < 5; ++i) {
out.println("<p>Hello, world!</p>");
}
%>This is just an example; it will produce:
<h1>It works!</h1>
<p>Hello, world!</p><p>Hello, world!</p><p>Hello, world!</p><p>Hello, world!</p><p>Hello, world!</p>And that's all for our website. Not too complicated, right?
And let's make our Dockerfile. Open yourproject/Dockerfile and copy&paste these:
FROM tomcat:9.0.1-jre8-alpine
ADD ./webapp /usr/local/tomcat/webapps/webapp
CMD ["catalina.sh", "run"]That's everything we need. Let me explain each line:
FROM tomcat:9.0.1-jre8-alpineWe use official tomcat:9.0.1-jre8-alpine image for our base image.
You can choose any other images you want, like tomcat:8.5.23-jre8.
But tomcat:9.0.1-jre8-alpine is the latest release of Apache Tomcat image on Docker Hub now
and has much smaller(~113MB) size than tomcat:9.0.1-jre8(~557MB) so I'll stick to use it.
ADD ./webapp /usr/local/tomcat/webapps/webappThe ADD instruction copies our local files(in our case, yourproject/webapp folder)
to container's file system(/usr/local/tomcat/webapps/webapp).
I tried to use a WAR file instead of plain source codes, but it didn't work for me for some reason.
If someone knows how to pre-compile all the JSP files and copy it into image, please leave a comment.
CMD ["catalina.sh", "run"]Finally, the CMD instruction will start up Apache Tomcat, which runs our web application.
Go to yourproject/ in terminal, and type it to build a Docker image:
$ docker build -t mywebapp .And then run:
$ docker run --rm -it -p 8888:8080 mywebappVisit http://localhost:8888/webapp to see if your website is running!
Sorry for late feedback. Today I'm just surprised that no single notification from Gist has come through GitHub notification center.
@jpwilliams000 I haven't used JSP for long time, actually I used JSP for that time only, thus there was no update on my progress.
@liuweiming1997 Thank you for pointing out that. I thought the slowness was natural thing in JSP&Tomcat ecosystem.
@granadacoder Thank you too, I didn't realised that on my machine.
@KUNTALDEB Well that tomcat image is based on openjdk image, I think the necessary steps are automatically done when you just use tomcat image. See https://github.com/docker-library/tomcat/blob/master/9.0/jre8-alpine/Dockerfile#L1 for the details.