docker-compose not showing logs for all containers

[bibiteix]

I'm using docker-compose for two containers and I run it using docker-compose up -d
But when I try to see its logs with docker-compose logs -f it shows me only the logs of one of the containers. I tried running the other container individually and it shows the logs just fine. I appreciate any help.

[shin-]

• Are you using a different log driver from json-file (default) or journald?
• What is the output of the docker-compose version command?
• Can you share your docker-compose.yml file?

[bibiteix]

journald

docker-compose version 1.11.2, build dfed245
docker-py version: 2.1.0
CPython version: 2.7.13
OpenSSL version: OpenSSL 1.0.1t  3 May 2016

services:
    service-whose-logs-are-not-showing:
        ports:
            - "5553:5554"
        image: image-name
        command: python3.4 /path/pythonfile.py
        volumes:
           - /path1:/path2
           - /path3:/path4
        user: "username"
        extra_hosts:
           - "mxgateway:172.16.1.1"
        restart: always
    service-whose-logs-are-showing:
        image: image-2-name
        command: <command>
        restart: always

Note that if I run image-name by itself, the logs appear just fine.
Thanks.

[bibiteix]

Hi, I just realized it was an issue with Python not flushing its stdout. I ended up adding the following code to my docker-compose.yml

environment:
     - PYTHONUNBUFFERED=1

Do you know if this is a common thing to happen with Docker?

[eulersson]

Oh god I spent good time chasing this up :) It happened to me while using Flask, I had to hit save on the python code so the server would restart and flush the accumulated error tracebacks.

Thanks a lot @bibiteix

[MCTRACO]

this issue was also happening to me with python.

[brean]

I figured out that for some error output in Python (in my case Tracebacks and "rospy.logerr") are not printed when you set tty: true. So in combination with setting "PYTHONUNBUFFERED=1" I also make sure to not use tty-mode.

[Dav3whit3]

@brean Thank you very much my man...I can stop headbutting my keyboard now. :3

[arshadnzr]

environment:
- PYTHONUNBUFFERED=1

Man , i knew it was an stdout issue. cause there was an error and i got the error.

Explanation on what happend
Linux outputs two types of log , which is stdout and stderr . for some reason docker is only printing stdout when run with compose . I guess its a good thing . Compose is used for multiple container managing stuff . and we dont want all the logs to clog up .