Docker, Supervisord and supervisor-stdout

Question

I'm trying to centralize output from supervisord and its processes using supervisor-stdout. But with this supervisord configuration:

#supervisord.conf

[supervisord]
nodaemon = true

[program:nginx]
command = /usr/sbin/nginx
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

(Note that the config section of supervisor-stoud is exactly the same as the example on the supervisor-stoud site).

...and this Dockerfile:

#Dockerfile

FROM python:3-onbuild

RUN apt-get update && apt-get install -y nginx supervisor

# Setup supervisord
RUN pip install supervisor-stdout
RUN mkdir -p /var/log/supervisor
COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
COPY nginx.conf /etc/nginx/nginx.conf

# restart nginx to load the config
RUN service nginx stop

# Start processes
CMD supervisord -c /etc/supervisor/conf.d/supervisord.conf -n

I can build the image just fine, but running a container from it gives me:

Error: supervisor_stdout:event_handler cannot be resolved within [eventlistener:stdout]

EDIT

The output from running:

supervisord -c /etc/supervisor/conf.d/supervisord.conf -n

is:

Error: supervisor_stdout:event_handler cannot be resolved within [eventlistener:stdout]
For help, use /usr/bin/supervisord -h

Answer 1

I had the same problem, in short, you need to install the Python package that provides that supervisor_stdout:event_handler handler. You should be able to by issuing the following commands:

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

If you have pip installed on that container, a simple:

pip install supervisor-stdout should suffice, more info about that specific package can be found here:

https://pypi.python.org/pypi/supervisor-stdout

AFAIK, there is no debian package that provides the supervisor-stdout, so the easiest method to install it is through pip.

Hope it helps whoever comes here as I did.

[Edit] As Vin-G suggested, if you still have a problem even after going through these steps, supervisord might be stuck in an old version. Try updating it.

Cheers!

Answer 2

I had the exact same problem and solved it by using Ubuntu 14.04 as a base image instead of Debian Jessie (I was using python:2.7 image which is based on Jessie).

You can refer to this complete working implementation: https://github.com/rehabstudio/docker-gunicorn-nginx.

EDIT: as pointed out by @Vin-G in his comment, it might be because the supervisor version shipped with Debian Jessie is too old. You could try to remove it from apt and install it with pip instead.