logs command quits if one container uses syslog.

[hervenicol]

If you run «docker-compose logs» and one container's logging driver is set to syslog, compose has an unexpected behaviour.
It may show logs from some of the containers that use default json-file logging driver, but exits as soon as it reaches a container using syslog. Sometimes it shows no logs at all.

docker-compose test file:

version: '2'

services:
  serviceA:
    image: ubuntu:16.04
    command: echo serviceA
    logging:
      driver: syslog
      options:
        syslog-address: "tcp://localhost:514"

  serviceB:
    image: ubuntu:16.04
    command: echo serviceB

Tests:

$ docker-compose logs
Attaching to testlogs_serviceB_1, testlogs_serviceA_1
ERROR: configured logging reader does not support reading
$ docker-compose logs
Attaching to testlogs_serviceB_1, testlogs_serviceA_1
serviceB_1  | serviceB
ERROR: configured logging reader does not support reading
$ 

I guess it should consistently show logs from containerA and containerB, like when logging driver is set to «none»:

$ docker-compose logs
Attaching to testlogs_serviceA_1, testlogs_serviceB_1
serviceA_1  | WARNING: no logs are available with the 'none' log driver
serviceB_1  | serviceB
$ 

Please note that I did not test how it behaves with other drivers.

Versions used:
Docker version 1.12.1, build 23cf638
docker-compose version 1.8.0, build f3628c7

[shin-]

Thanks for the report! Maybe we should exclude anything that doesn't use the default driver.

In the meantime, note that you should be able to do docker-compose logs serviceB to just show the logs for that service.

[mstenta]

Maybe we should exclude anything that doesn't use the default driver.

This seems like a big step backwards, considering that Docker itself supports many other log drivers. If the issue is in the docker-compose logs command, shouldn't it be fixed there? Rather than removing the ability to use all the other log drivers entirely?

I opened a new issue to discuss this: #4647

[vladyslav2]

@mstenta actually this "behavior" makes me wanna leave docker compose, why would you drop different logs drivers if docker supports them? Looks like a big limitation for docker-compose as for me