[Django]-Docker, Supervisord and logging – how to consolidate logs in docker logs?

I accomplished this using .

Install supervisor-stdout in your Docker image:

RUN apt-get install -y python-pip && pip install supervisor-stdout

Supervisord Configuration

Edit your supervisord.conf look like so:

[program:myprogram]
command=/what/ever/command
stdout_events_enabled=true
stderr_events_enabled=true

[eventlistener:stdout] 
command = supervisor_stdout 
buffer_size = 100 
events = PROCESS_LOG 
result_handler = supervisor_stdout:event_handler

Docker container is like a kleenex, you use it then you drop it. To be “alive”, Docker needs something running in foreground (whereas daemons run in background), that’s why you are using Supervisord.

So you need to “redirect/add/merge” process output (access and error) to Supervisord output you see when running your container.

As Drew said, everyone is using https://github.com/coderanger/supervisor-stdout to achieve it (to me this should be added to supervisord project!). Something Drew forgot to say, you may need to add

stdout_logfile=/dev/stdout
stdout_logfile_maxbytes=0

To the supervisord program configuration block.

Something very usefull also, imagine your process is logging in a log file instead of stdout, you can ask supervisord to watch it:

[program:php-fpm-log]
command=tail -f /var/log/php5-fpm.log
stdout_events_enabled=true
stderr_events_enabled=true

This will redirect php5-fpm.log content to stdout then to supervisord stdout via supervisord-stdout.

supervisor-stdout requires to install python-pip, which downloads ~150mb, for a container I think is a lot just for install another tool.

Redirecting logfile to /dev/stdout works for me:

stdout_logfile=/dev/stdout
stdout_logfile_maxbytes=0

http://veithen.github.io/2015/01/08/supervisord-redirecting-stdout.html

Today’s best practice is to have minimal Docker images. For me, ideal container with Python application contain just my code, supporting libraries and something like uwsgi if it is necessary.

I published one solution on https://github.com/msgre/uwsgi_logging. It is simple Django application behind uwsgi which is configured to display logs from uwsgi and Django app on containers stdout without need of supervisor.

I had the same problem with my python app (Flask). Solution that worked for me was to:

• Start supervisord in nodaemon mode (supervisord -n)

• Redirect log to /proc/1/fd/1 instead of /dev/stdout

• Set these two environment variables in my docker image PYTHONUNBUFFERED=True and PYTHONIOENCODING=UTF-8

Just add below line to your respective supervisor.ini config file.

redirect_stderr=true
stdout_logfile=/proc/1/fd/1

Export these variables to application (linux) environment.

$ export PYTHONUNBUFFERED=True 
$ export PYTHONIOENCODING=UTF-8

Indeed, starting supervisord in non-daemon mode is the best solution.

You could also use volumes in order to mount the supervisord’s logs to a central place.