Version 1.9 of package Dockerfile-Mode has just been released in NonGNU ELPA. You can now find it in M-x list-packages RET.
Dockerfile-Mode describes itself as: =========================================== Major mode for editing Docker's Dockerfiles =========================================== More at https://elpa.nongnu.org/nongnu/dockerfile-mode.html ## Summary: Provides a major mode `dockerfile-mode' for use with the standard `Dockerfile' file format. Additional convenience functions allow images to be built easily. ## Recent NEWS: [Not provided 🙁]