monit-docker --cmd does not propagate inner command exit code

[kfeina]

Title: monit-docker --cmd does not propagate inner command exit code

When using monit-docker monit --cmd, the exit code of the command executed inside the container is captured and printed in the ExecResult(exit_code=...) output, but it is not propagated as the exit code of monit-docker itself.

Example:

/usr/local/bin/monit-docker \
  --name signal-cli-rest-api-signal-cli-rest-api-1 \
  monit \
  --cmd '(bash -c "exit 1")'

echo $?

Current behavior:

INFO: ... ExecResult(exit_code=1, output=b'')
0

So the inner command failed with exit code 1, but monit-docker exits 0.

This makes it impossible to use --cmd directly from Monit check program, because Monit only sees the wrapper exit code and cannot react to the actual result of the command executed inside the container.

Expected behavior:

monit-docker should exit with the same exit code as the command executed inside the container, or alternatively provide an option such as:

--propagate-exit-code

so that:

monit-docker ... --cmd '(bash -c "exit 1")'
echo $?

would return:

1

This would make --cmd usable directly from Monit and other automation tools without requiring wrapper scripts that parse ExecResult(exit_code=...).

So basically the following doesn't work:

check program docker.signal-cli-rest-api.tmpfs with path "/usr/local/bin/monit-docker --name signal-cli-rest-api-signal-cli-rest-api-1 monit --cmd '(bash -c "/usr/local/bin/monit-checkFS-tmp.sh")' "
    if status != 0 for 2 cycles then alert
    group monit-dockers

root@slp-mon01:/etc/monit# monit status docker.signal-cli-rest-api.tmpfs
Monit 5.34.4 uptime: 2h 26m

Program 'docker.signal-cli-rest-api.tmpfs'
  status                       OK
  monitoring status            Monitored
  monitoring mode              active
  on reboot                    laststate
  last exit value              0
  last output                  INFO:2026-04-08 14:16:47: execute 'bash -c "/usr/local/bin/monit-checkFS-tmp.sh"' in signal-cli-rest-api-signal-cli-rest-api-1
                               INFO:2026-04-08 14:16:47: 'bash -c "/usr/local/bin/monit-checkFS-tmp.sh"' executed in signal-cli-rest-api-signal-cli-rest-api-1: ExecResult(exit_code=1, output=b'/tmp usage is  99% (> 80%)\n')
  data collected               Wed, 08 Apr 2026 14:17:44

Environment:

• monit-docker version: 0.50
• Docker host: Ubuntu
• Use case: monitor /tmp usage inside a container with a custom script returning 0 or 1