I have created a Gunicorn project, with accesslog and errorlog being specified in a config file, and then the server being started with only a -c flag to specify this config file.
The problem is, each time I restart the same Gunicorn process (via pkill -F <pidfile, also specified in config>), the files specified in these configs are emptied. I've got an info that it's because of the mode in which Gunicorn opens these files being "write", rather than "append", but haven't found anything about in the official settings.
How can I fix it? It's important because I tend to forget manually backing up these logs and had no capacity for automating it so far.
This was my mistake, and mostly unrelated to Gunicorn itself: I had a script that would have created any file not existing but still required, as it could have crashed the app server:
for file in [pidfile, accesslog, errorlog]:
os.makedirs(os.path.dirname(file), exist_ok=True)
f = open(file, "w")
File mode w always emptied the files. Making a rule that uses it for pidfile only, and a for the logfiles solved the problem.