X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsd_notify.xml;h=35f6f71ab37b00a6919e6912bd00e4ed4b648cc3;hp=346ec8f90b42d04a306eab914788885a296a3ea0;hb=9b15b7846d4de01bb5d9700a24077787e984e8ab;hpb=0675cc4a02dfa3e7abc47d0c2117bf413b1d7698
diff --git a/man/sd_notify.xml b/man/sd_notify.xml
index 346ec8f90..35f6f71ab 100644
--- a/man/sd_notify.xml
+++ b/man/sd_notify.xml
@@ -21,7 +21,8 @@
along with systemd; If not, see .
-->
-
+
sd_notify
@@ -45,7 +46,7 @@
sd_notify
sd_notifyf
- Notify service manager about start-up completion and other daemon status changes
+ Notify service manager about start-up completion and other service status changes
@@ -69,17 +70,17 @@
Description
- sd_notify() shall be called
- by a daemon to notify the init system about status
- changes. It can be used to send arbitrary information,
- encoded in an environment-block-like string. Most
- importantly it can be used for start-up completion
- notification.
+ sd_notify() may be called
+ by a service to notify the service manager about
+ state changes. It can be used to send arbitrary
+ information, encoded in an environment-block-like
+ string. Most importantly it can be used for start-up
+ completion notification.
If the unset_environment
- parameter is non-zero sd_notify()
+ parameter is non-zero, sd_notify()
will unset the $NOTIFY_SOCKET
- environment variable before returning (regardless
+ environment variable before returning (regardless of
whether the function call itself succeeded or
not). Further calls to
sd_notify() will then fail, but
@@ -87,7 +88,7 @@
processes.
The state parameter
- should contain an newline-separated list of variable
+ should contain a newline-separated list of variable
assignments, similar in style to an environment
block. A trailing newline is implied if none is
specified. The string may contain any kind of variable
@@ -98,58 +99,87 @@
READY=1
- Tells the init system
- that daemon startup is finished. This
- is only used by systemd if the service
- definition file has Type=notify
- set. The passed argument is a boolean
- "1" or "0". Since there is little
- value in signalling non-readiness, the
- only value daemons should send is
- "READY=1".
+ Tells the service
+ manager that service startup is
+ finished. This is only used by systemd
+ if the service definition file has
+ Type=notify set. Since there is little
+ value in signaling non-readiness, the
+ only value services should send is
+ READY=1
+ (i.e. READY=0 is
+ not defined).
+
+
+
+ RELOADING=1
+
+ Tells the service manager
+ that the service is reloading its
+ configuration. This is useful to allow
+ the service manager to track the service's
+ internal state, and present it to the
+ user. Note that a service that sends
+ this notification must also send a
+ READY=1
+ notification when it completed
+ reloading its
+ configuration.
+
+
+
+ STOPPING=1
+
+ Tells the service manager
+ that the service is beginning its
+ shutdown. This is useful to allow the
+ service manager to track the service's
+ internal state, and present it to the
+ user.
STATUS=...
Passes a single-line
- status string back to the init system
- that describes the daemon state. This
+ UTF-8 status string back to the service manager
+ that describes the service state. This
is free-form and can be used for
various purposes: general state
feedback, fsck-like programs could
pass completion percentages and
failing programs could pass a human
readable error message. Example:
- "STATUS=Completed 66% of file system
- check..."
+ STATUS=Completed 66% of file
+ system
+ check...
ERRNO=...
- If a daemon fails, the
+ If a service fails, the
errno-style error code, formatted as
- string. Example: "ERRNO=2" for
+ string. Example: ERRNO=2 for
ENOENT.
BUSERROR=...
- If a daemon fails, the
+ If a service fails, the
D-Bus error-style error code. Example:
- "BUSERROR=org.freedesktop.DBus.Error.TimedOut"
+ BUSERROR=org.freedesktop.DBus.Error.TimedOut
MAINPID=...
The main pid of the
- daemon, in case the init system did
+ service, in case the service manager did
not fork off the process
itself. Example:
- "MAINPID=4711"
+ MAINPID=4711
@@ -162,13 +192,12 @@
WatchdogSec= is
enabled for it. See
systemd.service5
- for details. It is recommended to send
- this message if the
- WATCHDOG_USEC=
- environment variable has been set for
- the service process, in every half the
- time interval that is specified in the
- variable.
+ for information how to enable this
+ functionality and
+ sd_watchdog_enabled3
+ for the details of how the service can
+ check if the the watchdog is enabled.
+
@@ -178,7 +207,7 @@
clashes.
Note that systemd will accept status data sent
- from a daemon only if the
+ from a service only if the
NotifyAccess= option is correctly
set in the service definition file. See
systemd.service5
@@ -197,68 +226,37 @@
errno-style error code. If
$NOTIFY_SOCKET was not set and
hence no status data could be sent, 0 is returned. If
- the status was sent these functions return with a
+ the status was sent, these functions return with a
positive return value. In order to support both, init
systems that implement this scheme and those which
- don't, it is generally recommended to ignore the return
+ do not, it is generally recommended to ignore the return
value of this call.
Notes
- These functions are provided by the reference
- implementation of APIs for new-style daemons and
- distributed with the systemd package. The algorithms
- they implement are simple, and can easily be
- reimplemented in daemons if it is important to support
- this interface without using the reference
- implementation.
+
Internally, these functions send a single
datagram with the state string as payload to the
- AF_UNIX socket referenced in the
+ AF_UNIX socket referenced in the
$NOTIFY_SOCKET environment
variable. If the first character of
- $NOTIFY_SOCKET is @ the string is
+ $NOTIFY_SOCKET is @, the string is
understood as Linux abstract namespace socket. The
datagram is accompanied by the process credentials of
- the sending daemon, using SCM_CREDENTIALS.
-
- For details about the algorithms check the
- liberally licensed reference implementation sources:
-
- resp.
-
- sd_notify() and
- sd_notifyf() are implemented in
- the reference implementation's
- sd-daemon.c and
- sd-daemon.h files. These
- interfaces are available as shared library, which can
- be compiled and linked to with the
- libsystemd-daemon
- pkg-config1
- file. Alternatively, applications consuming these APIs
- may copy the implementation into their source tree. For
- more details about the reference implementation see
- sd-daemon3.
-
- If the reference implementation is used as
- drop-in files and -DDISABLE_SYSTEMD is set during
- compilation these functions will always return 0 and
- otherwise become a NOP.
+ the sending service, using SCM_CREDENTIALS.
Environment
-
+
$NOTIFY_SOCKET
- Set by the init system
+ Set by the service manager
for supervised processes for status
and start-up completion
notification. This environment variable
@@ -275,9 +273,9 @@
Start-up Notification
- When a daemon finished starting up, it
+ When a service finished starting up, it
might issue the following call to notify
- the init system:
+ the service manager:
sd_notify(0, "READY=1");
@@ -285,7 +283,7 @@
Extended Start-up Notification
- A daemon could send the following after
+ A service could send the following after
completing initialization:
sd_notifyf(0, "READY=1\n"
@@ -297,7 +295,7 @@
Error Cause Notification
- A daemon could send the following shortly before exiting, on failure
+ A service could send the following shortly before exiting, on failure
sd_notifyf(0, "STATUS=Failed to start up: %s\n"
"ERRNO=%i",
@@ -312,7 +310,8 @@
systemd1,
sd-daemon3,
daemon7,
- systemd.service5
+ systemd.service5,
+ sd_watchdog_enabled3