[SOLVED] No write permissions in Linux container

[Manul]

I’ve set up a new instance of syncthing inside an LXC container. When trying to add a folder to sync, syncthing complains about missing permissions:

 2019-09-05 13:43:02: Failed to create folder marker: stat /home/syncthing/Musik/.stfolder: permission denied
 2019-09-05 13:43:02: Error on folder "Musik" (n3bfn-6f3h5): stat /home/syncthing/Musik/.stfolder: permission denied
 2019-09-05 13:45:17: Loading ignores: open /home/syncthing/Musik/.stignore: permission denied
 2019-09-05 13:45:17: Failed to create folder marker: stat /home/syncthing/Musik/.stfolder: permission denied
 2019-09-05 13:45:17: Error on folder "Musik" (n3bfn-6f3h5): stat /home/syncthing/Musik/.stfolder: permission denied 

However, I don’t see why it shouldn’t have the requested permissions: The user syncthing runs as has write permissions to the directory in question.

syncthing@syncthing:~$ ps -Ouser 92
  PID USER     S TTY          TIME COMMAND
   92 syncthi+ S ?        00:00:34 /usr/bin/syncthing -no-browser -no-restart -logflags=0
syncthing@syncthing:~$ id
uid=105(syncthing) gid=65534(nogroup) groups=65534(nogroup)
syncthing@syncthing:~$ ls -l /home/syncthing/Musik/.sttest
ls: cannot access '/home/syncthing/Musik/.sttest': No such file or directory
syncthing@syncthing:~$ touch /home/syncthing/Musik/.sttest
syncthing@syncthing:~$ ls -l /home/syncthing/Musik/.sttest
-rw-r--r-- 1 syncthing nogroup 0 Sep  5 11:57 /home/syncthing/Musik/.sttest
syncthing@syncthing:~$ syncthing --version
syncthing v1.2.2 "Fermium Flea" (go1.12.9 linux-amd64) deb@build.syncthing.net 2019-08-15 13:51:09 UTC

Any ideas anybody?

[calmh (Jakob Borg)]

It’s complaining specifically about the .stfolder directory. Does it have permissions on that, if it already exists? Volume mappings getting in the way? Security policy applied? Otherwise I don’t know, this is a permissions thing, double check those.

[Manul]

Thanks for your help.

Turns out the problem was the “nogroup” gid. Changing that to a regular one solved the issue.