Applies to both main branch v1.66 and legacyports v1.64.
While loading mod server checks if it has read-write access to mod directory.
If server fails to get read AND write access to mod directory, mod loading aborted: mod is marked as NOT FOUND in RPT log (console output); no mod files are read.
~$ cd Steam/steamapps/common/Arma\ 3\ Server ~/Steam/steamapps/common/Arma 3 Server$ chmod 555 mods/@CBA_A3
No need to use recursive chmod: mod's files and subdirectories can remain writeable. Server only checks access to mod's root directory itself.
~$ cd Steam/steamapps/common/Arma\ 3\ Server ~/Steam/steamapps/common/Arma 3 Server$ strace -ff -o /mnt/memdisk/arma3server ./arma3server -netlog -ip=192.168.153.1 -port=2302 -cfg=/home/steam/Steam/steamapps/common/Arma\ 3\ Server/cfg/arma3-server-modded.network.cfg -config=/home/steam/Steam/steamapps/common/Arma\ 3\ Server/cfg/arma3-server-modded.server.cfg -mod=mods/@CBA_A3 -servermod=mods/@CBA_A3 -bepath= -loadmissiontomemory 2>&1 | tee /mnt/memdisk/console.log
10:13:40 ============================================================================================= List of mods =============================================================================================== 10:13:40 modsReadOnly = true 10:13:40 safeModsActivated = false 10:13:40 customMods = true 10:13:40 hash = '9E6147A921E73C79788034EEBE98DAAADF5C2B89' 10:13:40 hashShort = '1f88dd0f' 10:13:40 name | modDir | default | origin | hash | hashShort | fullPath 10:13:40 ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 10:13:40 @CBA_A3 | @CBA_A3 | false | NOT FOUND | | | 10:13:40 Arma 3 DLC Bundle | dlcbundle | true | NOT FOUND | | | 10:13:40 Arma 3 Apex | expansion | true | GAME DIR | 889deca7b67b3edca0b2da51a5318a40167757dd | c794d30d | /home/steam/Steam/steamapps/common/Arma 3 Server/expansion 10:13:40 Arma 3 Marksmen | mark | true | GAME DIR | 7129193541b9133ea1bea45441e244eb180cbfe7 | 58644447 | /home/steam/Steam/steamapps/common/Arma 3 Server/mark 10:13:40 Arma 3 Helicopters | heli | true | GAME DIR | 037b8a52dea414a8999d947ae74a01089ef1178e | 6b140d2c | /home/steam/Steam/steamapps/common/Arma 3 Server/heli 10:13:40 Arma 3 Karts | kart | true | GAME DIR | 9b8fdc1c10171397e45e8a671074d3b570c758a9 | a5c8c24c | /home/steam/Steam/steamapps/common/Arma 3 Server/kart 10:13:40 Arma 3 Zeus | curator | true | GAME DIR | e3578d1509f22cc901180ed73925c9d766cdc84c | e6c7fc7b | /home/steam/Steam/steamapps/common/Arma 3 Server/curator 10:13:40 Arma 3 | A3 | true | NOT FOUND | | | 10:13:40 ==========================================================================================================================================================================================================
Notice "modsReadOnly = true" line. What does that mean?
Analyzing strace output: all I could grep out of strace logs on mod's name:
/mnt/memdisk$ egrep -nH CBA arma3server.*
arma3server.13327:1:execve("./arma3server", ["./arma3server", "-netlog", "-ip=192.168.153.1", "-port=2302", "-cfg=/home/steam/Steam/steamapps"..., "-config=/home/steam/Steam/steama"..., "-mod=mods/@CBA_A3", "-servermod=mods/@CBA_A3", "-bepath=", "-loadmissiontomemory"], [/* 26 vars */]) = 0
arma3server.13327:372:access("mods/@CBA_A3", R_OK|W_OK) = -1 EACCES (Permission denied)
arma3server.13327:380:access("/home/steam/.local/share/Arma 3\\mods/@CBA_A3", R_OK|W_OK) = -1 ENOENT (No such file or directory)
arma3server.13327:381:access("mods/@CBA_A3", R_OK|W_OK) = -1 EACCES (Permission denied)
arma3server.13327:67321:access("mods/@CBA_A3", R_OK|W_OK) = -1 EACCES (Permission denied)
arma3server.13327:67329:access("/home/steam/.local/share/Arma 3\\mods/@CBA_A3", R_OK|W_OK) = -1 ENOENT (No such file or directory)
arma3server.13327:67330:access("mods/@CBA_A3", R_OK|W_OK) = -1 EACCES (Permission denied)No tries to read any of mod's files. Also notice how backslash is incorrectly used as path delimiter. I don't have directory named "Arma 3\mods". In linux (and more generally, most unix) filesystems backslash is a valid character for file or directory name. And in those weird directory locations mods are checked for read-write access too.
Even on clean runs with write-enabled mod directory I couldn't find any evidence server actually writes anything. And writing there doesn't make too much sense anyway. However, even not being critical, this issue can lead to very subtle and hard-to-catch problems with mods. Any more or less complex configuration can hit it: running multiple servers with multiple users (you will need to add all users to one group and set write permissions for group); having one user for running server and other to manage mods and other content; unpacking from archive where mod dirs can have read-only mode; etc.
Now every admin has to check if his mod dirs have write permissions, when in fact only reading is required. That's odd.
console log (rpt):
@pedeathtrian Thanks for report, we´ll check your report and let you know. I´ll ask you about patience bucause it can tak a some time.
"some time" :D
Server needs write access to be able to lock the file, or atleast because it wants to lock the file, whether it needs it I dunno.