How to configure rsyslog for use with SysLogHandler logging class?

Question

In order to write log messages of "myapp" into /var/log/local5.log, I use SysLogHandler.

problem

"myapp" runs well, no error, but nothing gets logged, /var/log/local5.log remains empty.

logging configuration

Relevant parts of the logging configuration file:

handlers:
    mainHandler:
        class: logging.handlers.SysLogHandler
        level: INFO
        formatter: defaultFormatter
        address: '/dev/log'
        facility: 'local5'

loggers:
    __main__:
        level: INFO
        handlers: [mainHandler]

logging test

Here is how I try to write a log in the main script of "myapp":

with open('myconfig.yml') as f:
    logging.config.dictConfig(yaml.load(f))

log = logging.getLogger(__name__)
log.info("Starting")

I have added some sys.stderr.write() to /usr/lib/python3.4/logging/handlers.py to see what's happening and I get:

$ myapp
[SysLogHandler._connect_unixsocket()] Sucessfully connected to socket: /dev/log
[SysLogHandler.emit()] called
[SysLogHandler.emit()] msg=b'<174>2016/04/23 07:17:00.453 myapp: main: Starting\x00'
[SysLogHandler.emit()] msg sent to unix socket (no OSError)

rsyslog configuration

• /etc/rsyslog.conf (relevant parts; TCP and UDP syslog receptions are disabled):

  $ModLoad imuxsock # provides support for local system logging
  $ModLoad imklog   # provides kernel logging support
  
  [...]
  
  $IncludeConfig /etc/rsyslog.d/*.conf
  

• /etc/rsyslog.d/40-local.conf:

  local5.*                        /var/log/local5.log
  

rsyslog test

According to lsof output, it looks like rsyslogd is listening to /dev/log (or am I wrong?):

# lsof | grep "/dev/log"
lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1000/gvfs
      Output information may be incomplete.
rsyslogd  28044           syslog    0u     unix 0xffff8800b4b9b100       0t0    3088160 /dev/log
in:imuxso 28044 28045     syslog    0u     unix 0xffff8800b4b9b100       0t0    3088160 /dev/log
in:imklog 28044 28046     syslog    0u     unix 0xffff8800b4b9b100       0t0    3088160 /dev/log
rs:main   28044 28047     syslog    0u     unix 0xffff8800b4b9b100       0t0    3088160 /dev/log

I don't put the whole rsyslogd -N1 output since it's a bit long, but the mentionning"local" lines:

# rsyslogd -N1 | grep local
rsyslogd: version 7.4.4, config validation run (level 1), master config /etc/rsyslog.conf
3119.943361369:7f39080fc780: cnf:global:cfsysline: $ModLoad imuxsock # provides support for local system logging
3119.944034769:7f39080fc780: rsyslog/glbl: using '127.0.0.1' as localhost IP
3119.946084095:7f39080fc780: requested to include config file '/etc/rsyslog.d/40-local.conf'
3119.946135638:7f39080fc780: config parser: pushed file /etc/rsyslog.d/40-local.conf on top of stack
3119.946432390:7f39080fc780: config parser: resume parsing of file /etc/rsyslog.d/40-local.conf at line 1
3119.946678298:7f39080fc780: config parser: reached end of file /etc/rsyslog.d/40-local.conf
3119.946697644:7f39080fc780: Decoding traditional PRI filter 'local5.*'
3119.946723904:7f39080fc780: symbolic name: local5 ==> 168
3119.949560475:7f39080fc780: PRIFILT 'local5.*'
3119.949675782:7f39080fc780:   ACTION 0x224cda0 [builtin:omfile:/var/log/local5.log]
3119.953397587:7f39080fc780: PRIFILT 'local5.*'
3119.953806713:7f39080fc780:   ACTION 0x224cda0 [builtin:omfile:/var/log/local5.log]
rsyslogd: End of config validation run. Bye.

I don't understand what I am missing. rsyslog's documentation matching the version I use (7.4.4) seems outdated and I can't find my way in it. Not sure that's the place to find how to fix my problem.

EDITS:

• It's not possible to define a "personal" facility, like "myapp" (even if it's defined in rsyslog.conf, so I changed to use the 'local5' one.

Answer 1

Cause of the problem

I finally found out that I previously created /var/log/local5.log with inappropriate owner and group (root:root). They were inappropriate because /etc/rsyslog.conf tells explicitely owner and group should be syslog:syslog:

#
# Set the default permissions for all log files.
#
$FileOwner syslog
$FileGroup adm
$FileCreateMode 0640
$DirCreateMode 0755
$Umask 0022
$PrivDropToUser syslog
$PrivDropToGroup syslog

Unfortunately, the other log files rsyslog should take care of (like auth.log) were also root:root, so, seen from ls -lah, mine was not different from others... (what are also empty, I wonder why such a non-functional configuration is installed by default).

Unfortunately, rsyslog does not log any error (or at least I haven't found where).

Some more details that could be useful to finish rsyslog configuration

As a side note, rsyslog expects a special format for the messages it gets, and if it doesn't, it adds some informations, by default (timestamp hostname). It's possible to modify them. Anyway, from my python script, I decided to only send the message to log and let rsyslog format the output. So finally, the relevant parts of my logging configuration file are:

formatters:
    rsyslogdFormatter:
        format: '%(filename)s: %(funcName)s: %(message)s'

handlers:
    mainHandler:
        class: logging.handlers.SysLogHandler
        level: INFO
        formatter: rsyslogdFormatter
        address: '/dev/log'
        facility: 'local5'

loggers:
    __main__:
        level: INFO
        handlers: [mainHandler]

And I added a customized template in /etc/rsyslog.conf:

$template MyappTpl,"%$now% %timegenerated:12:23:date-rfc3339% %syslogtag%%msg%\n"

and accordingly modified /etc/rsyslog.d/40-local.conf:

local5.*                        /var/log/local5.log;MyappTpl

I also want to mention that the documentation provided by the matching package (rsyslog-doc for ubuntu) matches the installed version, of course, and provides hints I hadn't found in the online documentation.