[systemd-devel] 回复: Is it possible to send a string to the journal of one specific systemd unit

[Mantas Mikulėnas]

This option was added with util-linux v2.25 in 2014. If you're using an
older version or the Busybox `logger` instead, well, it won't have that.

The alternative is to write your own C tool that uses libsystemd and calls
sd_journal_send
<https://manpages.debian.org/testing/libsystemd-dev/sd_journal_send.3.en.html>()
with the correct fields (libsystemd is definitely going to be present), or
a Python tool that uses systemd.journal.send(). (Or maybe call libsystemd
through python ctypes or whatever other FFI mechanism is available.)



On Fri, Oct 22, 2021 at 4:32 PM DHAIY DHAIY <dhaiy at msn.com> wrote:

> Thanks a lot Mantas.
> But in my sytem, logger does not have "--journal".
> Are you aware of other tools from bash which can be used?
>
> BR
> ------------------------------
> *发件人:* Mantas Mikulėnas <grawity at gmail.com>
> *发送时间:* 2021年10月22日 18:45
> *收件人:* DHAIY DHAIY <dhaiy at msn.com>
> *抄送:* systemd-devel at lists.freedesktop.org <
> systemd-devel at lists.freedesktop.org>
> *主题:* Re: [systemd-devel] 回复: Is it possible to send a string to the
> journal of one specific systemd unit
>
> If you have root privileges (i.e. UID 0), then yes, you can send a journal
> message with the "OBJECT_SYSTEMD_UNIT=myservice.service" field and
> journalctl will automatically look for that.
>
> In C, specify the field when calling sd_journal_sendv(); in bash you can
> use `logger --journal`:
>
> (echo "OBJECT_SYSTEMD_UNIT=sshd.service";
>  echo "MESSAGE=Hello world!") | sudo logger --journal
>
> On Fri, Oct 22, 2021 at 11:43 AM DHAIY DHAIY <dhaiy at msn.com> wrote:
>
> Saying we have a systemd unit named "myservice".
>
> we can use *journalctl -u myservice* to inspect the logs generated by
> myservice.
>
>
> But is there a way to insert one string from command-line into myservice's
> journal so that it can be seen by *journalctl -u myservice* later?
>
> ------------------------------
> *发件人:* DHAIY DHAIY
> *发送时间:* 2021年10月22日 16:40
> *收件人:* systemd-devel at lists.freedesktop.org <
> systemd-devel at lists.freedesktop.org>
> *主题:* Is it possible to send a string to the journal of one specific
> systemd unit
>
>
> Saying we have a systemd unit named "myservice".
>
> we can use *journalctl -u myservice* to inspect the logs generated by
> myservice.
>
>
> But is there a way to insert one string from command-line into myservice's
> journal so that it can be seen by *journalctl -u myservice* later?
>
>
>
> --
> Mantas Mikulėnas
>


-- 
Mantas Mikulėnas
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