Docker Plugin on Linux

I've been trying to set up the Docker integration with PyCharm, following the instructions here: https://www.jetbrains.com/help/pycharm/2016.1/configuring-remote-interpreters-via-docker.html No luck, couldn't find the Docker option under the Project Interpreter settings, realized that it actually hadn't been installed by default.  Installed it, restarted PyCharm, and it's still not there.  Looking at the plugin notes, I see "Note: For the plugin to work properly, your IDE should be started using Java 7 or a later version.  For corresponding instructions, see Selecting the JDK version the IDE will run under."  This link goes to an IntelliJ troubleshooting article that says to change teh IDE boot JDK.  At this point, I'm lost, because I'm unable to find any .jdk file in the config folder.

Why is this so difficult?  Shouldn't plugins just work?