Use gosu and execs for execution

[bewing]

Use exec at the end of scripts in order to simplify the process chain
and signal handling. With this change, a SIGTERM sent by docker to
PID 1 will be propagated to the server binary for a clean shutdown.

Resolves #99

[bewing]

Want to do some more testing later (fresh data folder, user connect test, etc) before merging.

[wolveix]

Thanks for taking the time to open this PR! Let me know when you feel it's ready to be merged and has been tested sufficiently, and I'll test it my end too :)

[mitchellmaler]

Good call on the exec usage. Will test this locally.

[bewing]

Testing has shown that docker stop is still resulting in the process immediately exiting instead of the server binary performing an orderly shutdown. The latest changeset makes a slight change to run.sh, so that if desired, a user can override the UID/GID via docker run and use run.sh as the entrypoint, resulting in the server as PID 1.

eg, running
docker run --rm --name satisfactory.service -e MAXPLAYERS=8 -e STEAMBETA=false -v /mnt/local/storage:/config --user=1000:1000 --entrypoint /home/steam/run.sh -p 7777:7777/udp -p 15000:15000/udp -p 15777:15777/udp wolveix/satisfactory-server:latest

results in a running container satisfactory.service that can be issued a stop command. Adding -d is recommended if not using systemd or another system to control containers.

[bewing]

Going to take one more crack at this tonight after doing some research on sudo, signals, process groups and setsid. If that doesn't work, may have to just accept the partial solution in changeset 5cb8740

[bewing]

I played with this for another couple hours, and was unfortunately unable to get signal passing to work with the sudo call. Merging this partial fix does allow admins to bypass the sudo call after init.sh has been run at least once to set permissions on the volume mount.

[bewing]

More testing welcome, but it does appear to start the server correctly, and the environment appears intact:

$ docker exec -it testing /bin/bash
root@14bfcff225ce:/config# gosu steam env
PUID=1000
HOSTNAME=14bfcff225ce
SERVERGAMEPORT=7777
SERVERQUERYPORT=15777
PWD=/config
AUTOPAUSE=true
HOMEDIR=/home/steam
STEAMAPPID=1690800
SERVERIP=0.0.0.0
AUTOSAVEONDISCONNECT=true
AUTOSAVENUM=3
GAMECONFIGDIR=/config/gamefiles/FactoryGame/Saved
PGID=1000
STEAMBETA=false
CRASHREPORT=true
STEAMCMDDIR=/home/steam/steamcmd
SERVERBEACONPORT=15000
MAXPLAYERS=4
TERM=xterm
USER=steam
SKIPUPDATE=false
SHLVL=1
AUTOSAVEINTERVAL=300
DISABLESEASONALEVENTS=false
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
GAMESAVESDIR=/home/steam/.config/Epic/FactoryGame/Saved/SaveGames
DEBUG=false
_=/usr/sbin/gosu
HOME=/home/steam

[wolveix]

Thanks for your continued efforts! Couple of questions. Firstly, why did you duplicate the mkdir into run.sh? This serves no purpose as far as I can tell.

Secondly, with the inclusion of gosu, is signal trapping functioning correctly? If not, I want to avoid including unnecessary dependencies. Your last response isn't overly clear, so I just wanted to clarify :)

Edit: Reading over gosus source, it looks good and should be exactly what we need.

[bewing]

Thanks for your continued efforts! Couple of questions. Firstly, why did you duplicate the mkdir into run.sh? This serves no purpose as far as I can tell.

This leaves open the possibility of changing the entrypoint when running a container, and still being able to run /home/steam/run.sh if the end-user so desires. It does not appear to have a negative effect.

Secondly, with the inclusion of gosu, is signal trapping functioning correctly? If not, I want to avoid including unnecessary dependencies. Your last response isn't overly clear, so I just wanted to clarify :)

I tested by starting a container in the foreground, and issuing a stop from another terminal. The server received the signal and performed an orderly shutdown. I also tested on a detached container, and it was able to receive the signal as well.

[2021.12.02-19.18.53:466][  0FUnixPlatformMisc::RequestExitWithStatus
FUnixPlatformMisc::RequestExit
]LogWorld: BeginTearingDown for /Temp/Untitled_0
...
[2021.12.02-19.19.23:475][467]LogModuleManager: Shutting down and abandoning module RSA (3)
[2021.12.02-19.19.23:475][467]LogContentStreaming: Display: There are 1 unreleased StreamingManagers
[2021.12.02-19.19.23:478][467]LogExit: Exiting.
[2021.12.02-19.19.23:478][467]LogCore: FUnixPlatformMisc::RequestExit(bForce=false, ReturnCode=143)
Exiting abnormally (error code: 143)
Assertion failed: !HasCommands() [File:Runtime/RHI/Public/RHICommandList.h] [Line: 3816]

Pure virtual function called!
Signal 6 caught.

[wolveix]

Thanks for your continued efforts! Couple of questions. Firstly, why did you duplicate the mkdir into run.sh? This serves no purpose as far as I can tell.

This leaves open the possibility of changing the entrypoint when running a container, and still being able to run /home/steam/run.sh if the end-user so desires. It does not appear to have a negative effect.

It doesn't have a negative effect as such, it's just annoying to have a duplicate command as both instances must then be maintained.

If we're using gosu, then I think the possiblity of changing the entrypoint becomes an unnecessary and out-of-scope requirement to cater for.

[bewing]

It doesn't have a negative effect as such, it's just annoying to have a duplicate command as both instances must then be maintained.

If we're using gosu, then I think the possiblity of changing the entrypoint becomes an unnecessary and out-of-scope requirement to cater for.

Fair enough. I'll remove it from the changeset.
While I'm making changes, does it make sense to pass "$@" through the exec stack to allow additional server binary command line parameters to be passed via docker's CMD parameter?

ie docker run --rm ... wolveix/satisfactory-server:latest -foo=bar would result in Engine/Binaries/Linux/UE4Server-Linux-Shipping FactoryGame -log -NoSteamClient ... -foo=bar being eventually executed?

[wolveix]

Appreciate it!

No, you're probably right. Please remove it.

[msladek]

Just tested this and works as intended for my setup, much appreciated!

[wolveix]

Thanks for your hard work @bewing!