I am trying to redirect output of a systemd service to a file but it doesn't seem to work:


ExecStart=/usr/local/bin/binary1 agent -config-dir /etc/sample.d/server


Please correct my approach.


Ответы (8)

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:

SyslogIdentifier= # without any quote

Then, assuming your distribution is using rsyslog to manage syslogs, create a file in /etc/rsyslog.d/.conf with the following content:

if $programname == '' 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 ) but they will also be available in your file of choice.

Source via archive.org

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 >> /data/logs/xxx.log 2>&1'

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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:


It should be:


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:


NOTE: Make sure you create the directory already. I guess it does not support to create a directory.

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 >> /var/log/agent.log 2>&1"

Short answer:


If you don't want the files to be cleared every time the service is run, use append instead:


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="
Jun 30 15:02:15 host unitxxx[1437]: time="2018-06-30T13:02:15Z" level=info msg="
Jun 30 15:33:02 host unitxxx[1437]: time="2018-06-30T13:33:02Z" level=info msg="
Jun 30 15:56:31 host unitxxx[1437]: time="2018-06-30T13:56:31Z" level=info msg="

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
& stop

Restart rsyslog

systemctl restart rsyslog.service

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).

You possibly get this error:

Failed to parse output specifier, ignoring: /var/log1.log

From the systemd.exec(5) man page:


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.

На systemd.exec(5)странице руководства объясняются другие параметры, связанные с ведением журнала. Смотрите также systemd.service(5)и systemd.unit(5)страницы человека.

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>&1 > /var/log.log' 

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