Go away or I replace you with a Makefile

I remember the first time I tried to get an open-source project compiled and deployed. The distribution of Linux at this point was Slackware. Build or installation instructions didn’t exist, and without handholding on IRC, it would not have been possible for me. That was 30 years ago, people in IRC were very self-selected, patient, and helpful. When you have skilled patient people in IRC and you can communicate what you did, what exactly failed, and what you would have expected - your learning experience is pretty impressive. Nevertheless, it does not scale well. People nowadays expect things to work with a click of a button. They are even not keen on reading clear instructions.

Build OpenNMS with Docker

Being able to compiling an open-source project is important. You can change the code, so you should also able to build it.

Why is there a dedicated Docker image for the build environment? The dependencies running a pre-build OpenNMS Horizon distribution and compiling from source are different. To build OpenNMS Horizon you need Apache Maven and to compile JICMP, JRRD you need a C compiler environment. This is nothing you want to carry when you just want to run OpenNMS Horizon.