supervisord logs don't show my output
Question:
I have a [program:x] running and it prints / sys.stdout.writes a lot of things. None of which comes up in either in the AUTO childlogdir of [supervisord] or in stdout_logfile of [program:x]
Am I missing something?
How do I capture all that is printed or stdout-ed from [program:x] ?
In my program I am explicitly doing both,
print "something"
sys.stdout.write("something")
Relevant supervisord.conf file
[supervisord]
childlogdir = %(here)s/../logs/supervisord/
logfile = %(here)s/../logs/supervisord/supervisord.log
logfile_maxbytes = 100MB
logfile_backups = 10
loglevel = info
pidfile = %(here)s/../logs/supervisord/supervisord.pid
umask = 022
nodaemon = false
nocleanup = false
[program:x]
directory = %(here)s/../
command = python file.py
autostart=true
autorestart=true
redirect_stderr=true
stdout_logfile = /appropriate-path/to/access.log
Answers:
Python output is buffered. Setting the environment variable PYTHONUNBUFFERED=1 in you supervisord.conf will disable buffering and show log messages sooner:
[program:x]
environment = PYTHONUNBUFFERED=1
or add the -u command-line switch to python command:
[program:x]
command = python -u file.py
Alternatively you can flush the sys.stdout handler explicitly:
sys.stdout.flush()
On python 3.3 and up, you can add the flush=True parameter to have the function do this for you:
print(something, flush=True)
You can run your program like this:
python -u file.py
this will produce unbuffered output
If you have python based script that you can’t or don’t want to change to flush output on a regular base then you can use unbuffer from the Expect package.
For a Django application in a docker container I’ve lately used it like that (from a shell script run from supervisord):
unbuffer python -u manage.py runserver 0.0.0.0:11000 2>&1 >> /var/log/django.log
I have a [program:x] running and it prints / sys.stdout.writes a lot of things. None of which comes up in either in the AUTO childlogdir of [supervisord] or in stdout_logfile of [program:x]
Am I missing something?
How do I capture all that is printed or stdout-ed from [program:x] ?
In my program I am explicitly doing both,
print "something"
sys.stdout.write("something")
Relevant supervisord.conf file
[supervisord]
childlogdir = %(here)s/../logs/supervisord/
logfile = %(here)s/../logs/supervisord/supervisord.log
logfile_maxbytes = 100MB
logfile_backups = 10
loglevel = info
pidfile = %(here)s/../logs/supervisord/supervisord.pid
umask = 022
nodaemon = false
nocleanup = false
[program:x]
directory = %(here)s/../
command = python file.py
autostart=true
autorestart=true
redirect_stderr=true
stdout_logfile = /appropriate-path/to/access.log
Python output is buffered. Setting the environment variable PYTHONUNBUFFERED=1 in you supervisord.conf will disable buffering and show log messages sooner:
[program:x]
environment = PYTHONUNBUFFERED=1
or add the -u command-line switch to python command:
[program:x]
command = python -u file.py
Alternatively you can flush the sys.stdout handler explicitly:
sys.stdout.flush()
On python 3.3 and up, you can add the flush=True parameter to have the function do this for you:
print(something, flush=True)
You can run your program like this:
python -u file.py
this will produce unbuffered output
If you have python based script that you can’t or don’t want to change to flush output on a regular base then you can use unbuffer from the Expect package.
For a Django application in a docker container I’ve lately used it like that (from a shell script run from supervisord):
unbuffer python -u manage.py runserver 0.0.0.0:11000 2>&1 >> /var/log/django.log