How to redirect output of systemd service to a file

Question

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

User · Answer

You possibly get this error  Failed to parse output specifier  ignoring   var log1 log  From the systemd exec 5  man page   StandardOutput  Controls where file descriptor 1  STDOUT  of the executed processes is connected to  Takes one of inherit  null  tty  journal  syslog  kmsg  journal console  syslog console  kmsg console or socket   The systemd exec 5  man page explains other options related to logging  See also the systemd service 5  and systemd unit 5  man pages  Or maybe you can try things like this  all on one line   ExecStart  bin sh -c   usr local bin binary1 agent -config-dir  etc sample d server 2 gt  amp 1  gt   var log log

User · Answer

Short answer   StandardOutput file  var log1 log StandardError file  var log2 log   If you don t want the files to be cleared every time the service is run  use append instead   StandardOutput append  var log1 log StandardError append  var log2 log

User · Answer

We are using Centos7  spring boot application with systemd   I was running java as below  and setting StandardOutput to file was not working for me     ExecStart  bin java -jar xxx jar  -Xmx512-Xms32M    Below workaround solution working without setting StandardOutput  running java through sh as below      ExecStart  bin sh -c  exec  bin java -jar xxx jar -Xmx512M -Xms32M  gt  gt   data logs xxx log 2 gt  amp 1

User · Answer

If for a some reason can t use rsyslog  this will do   ExecStart  bin bash -ce  exec  usr local bin binary1 agent -config-dir  etc sample d server  gt  gt   var log agent log 2 gt  amp 1

User · Answer

Assume logs are already put to stdout stderr  and have systemd unit s log in  var log syslog  journalctl -u unitxxx service  Jun 30 13 51 46 host unitxxx 1437   time  2018-06-30T11 51 46Z  level info msg  127 0 0 1 Jun 30 15 02 15 host unitxxx 1437   time  2018-06-30T13 02 15Z  level info msg  127 0 0 1 Jun 30 15 33 02 host unitxxx 1437   time  2018-06-30T13 33 02Z  level info msg  127 0 0 1 Jun 30 15 56 31 host unitxxx 1437   time  2018-06-30T13 56 31Z  level info msg  127 0 0 1   Config rsyslog  System Logging Service     Create directory for log file mkdir  var log unitxxx    Then add config file  etc rsyslog d unitxxx conf  if  programname     unitxxx  then  var log unitxxx unitxxx log  amp  stop   Restart rsyslog  systemctl restart rsyslog service

User · 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  lt your program identifier gt    without any quote   Then  assuming your distribution is using rsyslog to manage syslogs  create a file in  etc rsyslog d  lt new file gt  conf with the following content   if  programname      lt your program identifier gt   then  path to log file log  amp  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  lt your program identifier gt   but they will also be available in your file of choice   Source via archive org

User · Answer

I would suggest adding stdout and stderr file in systemd service file itself   Referring   https   www freedesktop org software systemd man systemd exec html StandardOutput   As you have configured it should not like    StandardOutput  home user log1 log StandardError  home user log2 log   It should be    StandardOutput file  home user log1 log StandardError file  home user log2 log   This works when you don t want to restart the service again and again   This will create a new file and does not append to the existing file   Use Instead    StandardOutput append  home user log1 log StandardError append  home user log2 log   NOTE  Make sure you create the directory already  I guess it does not support to create a directory

User · Answer

If you have a newer distro with a newer systemd  systemd version 236 or newer   you can set the  values of StandardOutput or StandardError to file YOUR ABSPATH FILENAME     Long story   In newer versions of systemd there is a relatively new option  the github request is from 2016 ish and the enhancement is merged closed 2017 ish  where you can set the  values of StandardOutput or StandardError to file YOUR ABSPATH FILENAME  The file path option is documented in the most recent systemd exec man page   This new feature is relatively new and so is not available for older distros like centos-7  or any centos before that

[linux] How to redirect output of systemd service to a file

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