Can't clear subprocess's log

[potoo0]

Web interface and supervisorctl command line cannot clear logs.

env:

• os: Raspbian 9.8
• python: 3.5.3
• supervisor: 4.0.1

program:x

[program:test_cv]

directory = /home/pi/my_flask/monitor

command = /usr/bin/python3 /home/pi/my_flask/monitor/test_cv.py

user = root
# user = pi

priority = 50
autostart = false
autorestart = false
#startsecs = 5
#startretries = 3

redirect_stderr = true
stdout_logfile = /tmp/test_cv.log
stdout_logfile_maxbytes = 10MB
stdout_logfile_backups = 10

test_cv.py

#!/usr/bin/env python3
import cv2
import logging

logging.basicConfig(
    level=logging.INFO,
    format=r'%(asctime)s - %(filename)s[line:%(lineno)d]' +
    ' - %(levelname)s: %(message)s'
)

logging.info('cv2.__version__: {}'.format(cv2.__version__))

cam = cv2.VideoCapture(0 + cv2.CAP_V4L)
if not cam.isOpened():
    raise Exception('cam cannot open!')
ret3 = cam.set(3, 320)
ret4 = cam.set(4, 240)
ret, frame = cam.read()
logging.info('frame info: {}'.format(frame.shape))
logging.info('ret3: {}, ret4: {}'.format(ret3, ret4))
cam.release()
logging.info('released cam.')

Program cannot clear logs, so I changed user to root , changed log file mode to 777, but still didn't take affect.
Thank for your time and patience.

[mnaberez]

Duplicate of #804

The title of #804 references XML-RPC but supervisorctl, the web interface, and XML-RPC all use the same mechanism under the hood. The issue is that supervisord can't clear the log when the process is stopped, but can when the process is running.

[potoo0]

Thanks.