doc: service indication example

2 files changed, 33 insertions, 2 deletions

diff --git a/doc/admin/service-dbus/index.rst b/doc/admin/service-dbus/index.rst
index dab439a..e35577c 100644
--- a/doc/admin/service-dbus/index.rst
+++ b/doc/admin/service-dbus/index.rst
@@ -6,8 +6,8 @@ the systemd D-Bus interface).
 It allows to enumerate system services and get their status, start/stop/restart/...
 a service and enable/disable a service.
 
-The provider should be also able to do event based monitoring of service status
-(emit indication event upon service status change) in the future.
+The provider is also able to do event based monitoring of service status
+(emit indication event upon service property change).
 
 Contents:
 
diff --git a/doc/admin/service-dbus/usage.rst b/doc/admin/service-dbus/usage.rst
index 2d8c706..cb70d31 100644
--- a/doc/admin/service-dbus/usage.rst
+++ b/doc/admin/service-dbus/usage.rst
@@ -44,3 +44,34 @@ Disable and enable 'cups' service, print EnabledDefault property::
     print cups.EnabledDefault
     cups.TurnServiceOn()
     print cups.EnabledDefault
+
+Indications
+-----------
+OpenLMI Service provider is able (using indication manager and polling) to emit indication
+event upon service (i. e. :ref:`LMI_Service <LMI-Service>` instance) property modification
+(:ref:`LMI_ServiceInstanceModificationIndication <LMI-ServiceInstanceModificationIndication>`).
+
+This is useful mainly for being notified when a service has changed state (has been started,
+or stopped).
+
+In order to receive indications, create instances of CIM_IndicationFilter (which indications
+should be delivered), CIM_IndicationHandler (what to do with those indications) and
+CIM_IndicationSubscription (links filter and handler together).
+
+The following example in LMIShell does it all in one step::
+
+    c.subscribe_indication(
+        Name="service_modification",
+        QueryLanguage="DMTF:CQL",
+        Query="SELECT * FROM LMI_ServiceInstanceModificationIndication WHERE SOURCEINSTANCE ISA LMI_Service",
+        CreationNamespace="root/interop",
+        SubscriptionCreationClassName="CIM_IndicationSubscription",
+        FilterCreationClassName="CIM_IndicationFilter",
+        FilterSystemCreationClassName="CIM_ComputerSystem",
+        FilterSourceNamespace="root/cimv2",
+        HandlerCreationClassName="CIM_IndicationHandlerCIMXML",
+        HandlerSystemCreationClassName="CIM_ComputerSystem",
+        Destination="http://localhost:12121"
+    )
+
+Indications are sent to the location specified in 'Destination' argument.