Add Compose shm_size service option support

[surenkov]

Since --shm-size option is supported by nerdctl run command, it is also nice to have its counterpart from Compose file specification.

Example configuration

version: '3.9'

services:
  test-plain:
    image: debian:buster-slim
    command: grep shm /proc/self/mounts
  test-shm:
    image: debian:buster-slim
    shm_size: 1G
    command: grep shm /proc/self/mounts

Before fix:

$ nerdctl compose -f compose.yml run test-plain
INFO[0000] Ensuring image debian:buster-slim
INFO[0000] Creating container nerdctl_test-plain_run_bdf02686b2bc
shm /dev/shm tmpfs rw,nosuid,nodev,noexec,relatime,size=65536k,uid=501,gid=1000,inode64 0 0

$ nerdctl compose -f compose.yml run test-shm
WARN[0000] Ignoring: service test-shm: [ShmSize]
INFO[0000] Ensuring image debian:buster-slim
INFO[0000] Creating container nerdctl_test-shm_run_0715f6c50f71
shm /dev/shm tmpfs rw,nosuid,nodev,noexec,relatime,size=65536k,uid=501,gid=1000,inode64 0 0

After fix:

$ nerdctl compose -f compose.yml run test-plain
INFO[0000] Ensuring image debian:buster-slim
INFO[0000] Creating container nerdctl_test-plain_run_128ffac7cffb
shm /dev/shm tmpfs rw,nosuid,nodev,noexec,relatime,size=65536k,uid=501,gid=1000,inode64 0 0

$ nerdctl compose -f compose.yml run test-shm
INFO[0000] Ensuring image debian:buster-slim
INFO[0000] Creating container nerdctl_test-shm_run_e6afbb4dbe93
shm /dev/shm tmpfs rw,nosuid,nodev,noexec,relatime,size=1048576k,uid=501,gid=1000,inode64 0 0

[AkihiroSuda]

Thanks, could you squash commits?

[surenkov]

@AkihiroSuda done, thank you!

[AkihiroSuda]

Thanks