How to redirect output of systemd service to a file
I am trying to redirect output of a systemd service to a file but it doesn't seem to work:
[Unit]
Description=customprocess
After=network.target
[Service]
Type=forking
ExecStart=/usr/local/bin/binary1 agent -config-dir /etc/sample.d/server
StandardOutput=/var/log1.log
StandardError=/var/log2.log
Restart=always
[Install]
WantedBy=multi-user.target
Please correct my approach.
Answer
I think there's a more elegant way to solve the problem: send the stdout/stderr to syslog with an identifier and instruct your syslog manager to split its output by program name.
Use the following properties in your systemd service unit file:
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=<your program identifier> # without any quote
Then, assuming your distribution is using rsyslog to manage syslogs, create a file in /etc/rsyslog.d/<new_file>.conf with the following content:
if $programname == '<your program identifier>' then /path/to/log/file.log
& stop
Now make the log file writable by syslog:
# ls -alth /var/log/syslog
-rw-r----- 1 syslog adm 439K Mar 5 19:35 /var/log/syslog
# chown syslog:adm /path/to/log/file.log
Restart rsyslog (sudo systemctl restart rsyslog) and enjoy! Your program stdout/stderr will still be available through journalctl (sudo journalctl -u <your program identifier>) but they will also be available in your file of choice.