Please provide a headless server binary

[ouryperd]

This is a feature request for a headless server edition.

[isilkor]

@lluchs Can we just upload_snapshot.sh another binary or do we need some changes on the backend?

[lluchs]

I think we'll want a separate Travis build for this to get a minimal server binary. I believe it would still link with audio libraries and other unnecessary stuff otherwise.

We'll also need another target that installs the server binary and supporting files (but not the music) for creating an AppImage. I'll look into that, we also need that for a mape snapshot.

[jcaesar]

Out of curiosity, @ouryperd: why is building it yourself not an option for you?

[ouryperd]

from looking at it briefly, the install has a lot of dependencies for X. I've briefly looked at building but I am out of my depth.

[jcaesar]

I do wonder whether HEADLESS_ONLY still works.

[jcaesar]

@lluchs For me, compiling with or without HEADLESS_ONLY links exactly the same set of libraries, and no audio libraries, so you might not need another target:

linux-vdso.so.1
libpng16.so.16
libz.so.1
libjpeg.so.62
libreadline.so.8
libtinfo.so.6
libtinyxml.so.2
libminiupnpc.so.17
libpthread.so.0
librt.so.1
libdw.so.1
libstdc++.so.6
libm.so.6
libgcc_s.so.1
libc.so.6
libtinfow.so.6
/lib64/ld-linux-x86-64.so.2 
libelf.so.1
libdl.so.2
liblzma.so.5
libbz2.so.1

(Linking miniupnpc is maybe not so nice either…)

[lluchs]

The way our CMake definitions are set up, it enables optional features based on whether the library is available, even though only a small subset is actually required. So you need to run the build in a virtual machine / container with only the stuff that's actually required. See here for an example - only zlib, libjpeg and libpng are required for a minimal build (looks like it's also linking to readline there, though).

builds.sr.ht also has Alpine, maybe we could get a statically-linked minimal openclonk-server build out of that.

[jcaesar]

Thinking about it… if it's already a static binary, having readline built in might be neat.