Overview
This document will describe how to enable a custom script-based alert dispatcher which is capable of responding to Ambari alerts. The dispatcher will invoke a script with the parameters of the alert as command line arguments.
Configuration Changes
The dispatcher must know the location of the script that is being executed. This is configured through ambari.properties
by setting either:
notification.dispatch.alert.script
- a custom property key that points to the script, such as
foo.bar.alert.dispatch.script
Some examples of this are:
notification.dispatch.alert.script=/contrib/ambari-alerts/scripts/default_logger.py
com.mycompany.dispatch.syslog.script=/contrib/ambari-alerts/scripts/legacy_sys_logger.py
com.mycompany.dispatch.shell.script=/contrib/ambari-alerts/scripts/shell_logger.sh
Script Call
When an alert instance changes state and Ambari needs to dispatch that alert state change, the custom script will be invoked:
# main method which is called when invoked on the command line # :param definitionName: the alert definition unique ID # :param definitionLabel: the human readable alert definition label # :param serviceName: the service that the alert definition belongs to # :param alertState: the state of the alert (OK, WARNING, etc) # :param alertText: the text of the alert def main(): definitionName = sys.argv[1] definitionLabel = sys.argv[2] serviceName = sys.argv[3] alertState = sys.argv[4] alertText = sys.argv[5]
API Calls
Alert Dispatch Target Creation
POST api/v1/alert_targets
{
"AlertTarget": {
"name": "syslogger",
"description": "Syslog Target",
"notification_type": "ALERT_SCRIPT",
"global": true
}
}
The above call will create a global alert target that will dispatch all alerts across all alert groups. Without specifying ambari.dispatch-property.script
as a property of the alert target, Ambari will look for the default configuration key of notification.dispatch.alert.script
in ambari.properties
.
Custom Script For Dispatch Target
POST api/v1/alert_targets
{
"AlertTarget": {
"name": "syslogger",
"description": "Syslog Target",
"notification_type": "ALERT_SCRIPT",
"global": true,
"properties": {
"ambari.dispatch-property.script": "com.mycompany.dispatch.syslog.script"
}
}
}
The above call also creates a global alert target. However, a specific script key is being specified. The result is that ambari.properties
should contain something similar to:
com.mycompany.dispatch.syslog.script=/contrib/ambari-alerts/scripts/legacy_sys_logger.py