Using Docker to solve my JAVA woes

Occasionally you encounter a problem that resurfaces every 6 months or so that you wish never would come back again. One of those problems is running multiple versions of Java (for various reasons) and toggling between those versions. "Jenv" works pretty well on a Mac, but sometimes when you are talking about libraries and java plugins it goes back to being complex.

For this last round, I took a different approach. What if I created a docker container that had everything I needed for that task? Then I could reuse that container whenever I needed and did not need to make any changes to my host system. My challenge this time around was connecting to an Avocent KVM switch that could only support a very old version of JAVA webstart.

I started with a basic Debian Wheezy container and added all the JAVA parts that I needed, then setup VNC to connect to the container. Downloading and launching the container is pretty easy if you follow the directions here https://hub.docker.com/r/paklids/jnlp-helper/ .

After that, there are a few other steps to follow.

#1 VNC to the container. I'm using RealVNC on a Mac, but you may use another method (My coworker used the Safari browser)

#2 After the window opens (using the correct password) then launch firefox from the text console

#3 Use firefox to browse to your Avocent KVM (or whatever site you need the older JAVA for - like those that use JNLP's)

#4 Accept any SSL exceptions. Even if you resolve the SSL problems with your appliance, you will still need to use an older version of JAVA which in itself is likely insecure. Now login to your device:

#5 Click on any of the links that uses Java Webstart (like JNLP links). Use the "Open with" context and select browse:

#6 Show other applications and then select "IcedTea Java Web Start"

At this point your Java Webstart application should start. I'll try to publish my Dockerfile so that if you need to tweak for your own purposes then you have a good base to start from. Enjoy!