docker-alpine
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gliderlabs
/var/run symlinked to /run in 3.7 image
The alpine:3.7 image has a symlink from /var/run to /run, whereas 3.6 and 3.5 did not. Is this intentional? I can't find any notes about it.
The difference threw me off in images like nginx:1.13.9-alpine, which just updated from Alpine Linux 3.5 to 3.7 as its base. I run nginx containers as read only and mount a tmpfs volume at /var/run. This broke with the symlink.
alpine:3.7
/ # ls -al /var
total 44
drwxr-xr-x 11 root root 4096 Jan 9 19:37 .
drwxr-xr-x 1 root root 4096 Mar 15 23:23 ..
drwxr-xr-x 4 root root 4096 Jan 9 19:37 cache
dr-xr-xr-x 2 root root 4096 Jan 9 19:37 empty
drwxr-xr-x 5 root root 4096 Jan 9 19:37 lib
drwxr-xr-x 2 root root 4096 Jan 9 19:37 local
drwxr-xr-x 3 root root 4096 Jan 9 19:37 lock
drwxr-xr-x 2 root root 4096 Jan 9 19:37 log
drwxr-xr-x 2 root root 4096 Jan 9 19:37 opt
lrwxrwxrwx 1 root root 4 Jan 9 19:37 run -> /run
drwxr-xr-x 3 root root 4096 Jan 9 19:37 spool
drwxrwxrwt 2 root root 4096 Jan 9 19:37 tmp
alpine:3.6
/var # ls -al /var
total 48
drwxr-xr-x 12 root root 4096 Jan 9 19:36 .
drwxr-xr-x 1 root root 4096 Mar 15 23:18 ..
drwxr-xr-x 4 root root 4096 Jan 9 19:36 cache
dr-xr-xr-x 2 root root 4096 Jan 9 19:36 empty
drwxr-xr-x 5 root root 4096 Jan 9 19:36 lib
drwxr-xr-x 2 root root 4096 Jan 9 19:36 local
drwxr-xr-x 3 root root 4096 Jan 9 19:36 lock
drwxr-xr-x 2 root root 4096 Jan 9 19:36 log
drwxr-xr-x 2 root root 4096 Jan 9 19:36 opt
drwxr-xr-x 2 root root 4096 Jan 9 19:36 run
drwxr-xr-x 3 root root 4096 Jan 9 19:36 spool
drwxrwxrwt 2 root root 4096 Jan 9 19:36 tmp
Yes, this was intentional because many applications are now using /run instead of /var/run to comply with FHS 3.0. Accordin FHS 3.0, it is perfectly valid to implement /var/run as a symlink to /run.
Does it work if you mount /run as tmpfs instead?
I had a similar problem because I was mounting /var/run/postgresql/ to share unix sockets between containers. Fixed by moving directly to /var/postgresql/.
