No base image for Ubuntu 24.04

[slonopotamus]

ue4-docker uses nvidia/opengl image as a base. However, nvidia/opengl seems to be abandoned (last image was published 2 years ago).

There's an issue for 24.04 support, but there's no activity yet.

Possible solutions:

• Switch from nvidia/opengl to just ubuntu
• Use nvidia/cuda always (even without --cuda flag)

[TBBle]

I had assumed the cuda image is a superset of the opengl image, so that seemed like the lowest-friction option.

Although a quick check shows that the cuda images use

ENV NVIDIA_DRIVER_CAPABILITIES compute,utility

while the opengl images used

ENV NVIDIA_DRIVER_CAPABILITIES \
        ${NVIDIA_DRIVER_CAPABILITIES:+$NVIDIA_DRIVER_CAPABILITIES,}graphics,compat32,utility

Also, the cuda build does not include the OpenGL runtime libraries and egl enablement or development libs so simply overriding NVIDIA_DRIVER_CAPABILITIES might not be enough (although we might be overriding that already; I know we discussed that env-var in the back tracker years ago.)

So cuda may not actually be a valid substitution here for people who actually want opengl support to work, and I assume ubuntu wouldn't be a valid switch either since it won't have the env-changes etc. to make nvidia-container-runtime work.

That said, if the upstream is dead, perhaps we do just bite the bullet, drop the opengl support, and use ubuntu as a base, and if anyone does need the opengl support, see if we can perhaps build something on top of the cuda image to make it work.

Does UE even use OpenGL anymore? Or was this just a convenient way to get the in-container side of the nvidia-container-runtime setup? If the latter, then cuda, perhaps with an override for NVIDIA_DRIVER_CAPABILITIES might actually be sufficient, and remains the lowest-friction option.

[slonopotamus]

Does UE even use OpenGL anymore?

Nope, OpenGL renderer is dead since somewhere about 4.25 (which I'm trying to drop in #370).