Change systemd unit tag send to journalctl/syslog

SyslogIdentifier= Sets the process name ("syslog tag") to prefix log lines sent to the logging system or the kernel log buffer with. If not set, defaults to the process name of the executed process. This option is only useful when StandardOutput= or StandardError= are set to journal, syslog or kmsg (or to the same settings in combination with +console) and only applies to log messages written to stdout or stderr.

https://www.freedesktop.org/software/systemd/man/systemd.exec.html#SyslogIdentifier=

This overrides the SYSLOG_IDENTIFIER field in journalctl output.

# cat /etc/systemd/system/prvzn.service | grep prvzn
ExecStart=/opt/infra/prvzn exec --config-dir ${CONFIG_DIR} 
SyslogIdentifier=prvzn-foobar

Results in journalctl lines like this:

# journalctl | grep prvzn | tail -n1
Apr 30 08:29:16 ro01 prvzn-foobar[31787]: prvzn (info)2018/04/30 08:29:16 evaluation successful.

I am running a mix of different versions of Ubuntu (14.04, 16.04, 17.10) and CentOS (7) ...my own struggle is that systemd has been changing rapidly and many config options don't work consistently or in some cases aren't even available between versions. Check the man pages for your specific version of systemd. ymmv