org.freedesktop.LogControl1 — D-Bus interface to query and set logging configuration
org.freedesktop.LogControl1 is a generic interface that is intended
to be used by any daemon which allows the log level and target to be set over D-Bus. It is implemented by
various daemons that are part of the
systemd(1) suite.
It is assumed that those settings are global for the whole program, so a fixed object path is
used. The interface should always be available under the path
/org/freedesktop/LogControl1.
The following interface is exposed:
node /org/freedesktop/LogControl1 {
interface org.freedesktop.LogControl1 {
properties:
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
@org.freedesktop.systemd1.Privileged("true")
readwrite s LogLevel = '...';
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
@org.freedesktop.systemd1.Privileged("true")
readwrite s LogTarget = '...';
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly s SyslogIdentifier = '...';
};
interface org.freedesktop.DBus.Peer { ... };
interface org.freedesktop.DBus.Introspectable { ... };
interface org.freedesktop.DBus.Properties { ... };
};
LogLevel describes the
syslog(3)-style
log-level, and should be one of "emerg", "alert",
"crit", "err", "warning", "notice",
"info", "debug", in order of increasing verbosity.
LogTarget describes the log target (mechanism). It should be one of
"console" (log to the console or standard output),
"kmsg" (log to the kernel ring buffer),
"journal" (log to the journal natively, see
systemd-journald.service(8)),
"syslog" (log using the
syslog(3) call).
Those two properties are writable, so they may be set by sufficiently privileged users.
SyslogIdentifier is a read-only property that shows the "syslog identifier".
It is a short string that identifies the program that is the source of log messages that is passed to
the syslog(3) call.
journalctl option -p/--priority= may be used
to filter log messages by log level, option -t/--identifier= may be
used to by the syslog identifier, and filters like "_TRANSPORT=syslog",
"_TRANSPORT=journal", and "_TRANSPORT=kernel" may be used to filter
messages by the mechanism through which they reached systemd-journald.
systemctl log-level and systemctl log-target verbs may be
used to query and set the LogLevel and LogTarget properties of the
service manager. systemctl service-log-level and systemctl
service-log-target may similarly be used for individual services. (Services must have the
BusName= property set and must implement the interface described here. See
systemd.service(5)
for details about BusName=.)