What is the SELinux? Some of the most frustrating but rewarding feelings come from those “a-ha!” moments. One of my favorite sayings is that your only difficult problems are the ones you are currently facing, as you already have solutions for resolved problems. Let me tell you about my “a-ha!” moments with SELinux, and how I’ve started to love documentation. As a brief summary, SELinux is “a mandatory access control (MAC) security mechanism implemented in the kernel” developed and maintained by the https://wiki.