ServiceNow Event Manager Events

The ServiceNow Event Manager Events stream connector allows you to send data from Centreon to ServiceNow Event Manager instances.

Before starting

• In most cases, you will want to send data from the central server. It is also possible to send it from a remote server or a poller (e.g. if you want to avoid the central server being a SPOF, or if you are an MSP and you install the stream connector on a poller or a remote server within your customer's infrastructure).
• By default, the ServiceNow Event Manager Events stream connector sends data from host_status and service_status Broker events. The event format is shown here.
• These events are sent each time a host or a service is checked. Various parameters let you filter out events.

Installation

Perform the installation on the server that will send data to ServiceNow Event Manager (central server, remote server, poller).

1. Login as root using your favorite SSH client.

2. Run the following command:

Alma / RHEL / Oracle Linux 8

dnf install centreon-stream-connector-servicenow

Alma / RHEL / Oracle Linux 9

dnf install centreon-stream-connector-servicenow

Debian 11 & 12

apt install centreon-stream-connector-servicenow

Configuring your ServiceNow Event Manager equipment

You may need to configure your ServiceNow Event Manager equipment so that it can receive data from Centreon. Please refer to ServiceNow Event Manager's documentation. Make sure ServiceNow Event Manager is able to receive data sent by Centreon: flows must not be blocked by ServiceNow Event Manager's configuration or by a security equipment.

Configuring the stream connector in Centreon

1. On your central server, go to Configuration > Pollers > Broker configuration.
2. Click on central-broker-master (or the appropriate broker configuration if it is a poller or a remote server that will send events).
3. On the Output tab, select Generic - Stream connector from the list and then click Add. A new output appears in the list.
4. Fill in the fields as follows:

Field	Value
Name	Servicenow events
Path	/usr/share/centreon-broker/lua/servicenow-em-events-apiv2.lua
Filter category	Neb

5. To enable Centreon to connect to your ServiceNow Event Manager equipment, fill in the following mandatory parameters. The fields for the first entry are already present. Click on the +Add a new entry link located below the Filter category table to add another one.

Type	Name	Value explanation	Value exemple
string	instance	The name of the ServiceNow instance	MyCompany
string	client_id	The Oauth client_id
string	client_secret	The Oauth client_secret
string	username	The Oauth user
string	password	The Oauth password

6. Fill in any optional parameters you want (using the +Add a new entry link):

Type	Name	Value explanation	default value
string	logfile	The file in which logs are written	/var/log/centreon-broker/servicenow-em-stream-connector.log
number	log_level	Logging level from 1 (errors) to 3 (debug)	1

7. Use the stream connector's optional parameters to filter or adapt the data you want Centreon to send to ServiceNow Event Manager.

8. Deploy the configuration.

9. Restart centengine on all pollers:

   systemctl restart centengine

ServiceNow Event Manager should now receive data from Centreon. To test if it is working, see Curl commands: testing the stream connector.

Filtering or adapting the data you want to send to ServiceNow Event Manager

All stream connectors have a set of optional parameters, that allow you to filter the data you will send to your ServiceNow Event Manager equipment, to reformat the data, to define a proxy...

Each optional parameter has a default value, that is indicated in the corresponding documentation.

• To override the default value of a parameter, click on the +Add a new entry link located below the Filter category table to add a custom parameter. For example, if you want to only send to ServiceNow Event Manager the events handled by a poller named "poller-1", enter:

  type = string
  name = accepted_pollers
  value = poller-1

• For the ServiceNow Event Manager Events stream connector, the following values always override the default values, you do not need to define them in the interface.

Some of them are overridden by this stream connector.

Type	Name	Default value for the stream connector
string	accepted_categories	neb
string	accepted_elements	host_status,service_status

Event bulking

This stream connector is compatible with event bulking. Meaning that it is able to send more that one event in each call to the ServiceNow Event Manager REST API.

To use this feature you must add the following parameter in your stream connector configuration.

Type	Name	Value
number	max_buffer_size	more than one

Event format

This stream connector will send event with the following format.

service_status event

{
  "records": [{
    "source": "centreon",
    "event_class": "centreon",
    "severity": 5,
    "node": "my_host",
    "resource": "my_service",
    "time_of_event": "2022-09-06 11:52:12",
    "description": "CRITICAL: USB cable behaving like a water hose"
  }]
}

host_status event

{
  "records": [{
    "source": "centreon",
    "event_class": "centreon",
    "severity": 5,
    "node": "my_host",
    "resource": "my_host",
    "time_of_event": "2022-09-06 11:52:12",
    "description": "DOWN: someone plugged an UPS on another UPS to create infinite energy"
  }]
}

Custom event format

This stream connector allows you to change the format of the event to suit your needs. Only the event part of the json is customisable. It also allows you to handle event types that are not handled by default such as ba_status events.

In order to use this feature you need to configure a json event format file and add a new stream connector parameter.

Type	Name	Value
string	format_file	/etc/centreon-broker/servicenow-em-events-format.json

The event format configuration file must be readable by the centreon-broker user.

To learn more about custom event formats and templating files, visit this page.

Curl commands: testing the stream connector

Here is the list of all the curl commands that are used by the stream connector.

You must replace all the <xxxx> inside the below commands with their appropriate value. <instance> may become MyCompany.

Get OAuth tokens

If you want to test if you can get 0Auth tokens from ServiceNow Event Manager correctly:

1. Log in to the server that you configured to send events to ServiceNow Event Manager (your central server, a remote server or a poller).
2. Run the following command:

curl -X POST -H "Content-Type: application/x-www-form-urlencoded" 'https://<instance_name>.service-now.com/oauth_token.do' -d 'grant_type=password&client_id=<client_id>&client_secret=<client_secret>&username=<username>&password=<password>'

Refresh OAuth tokens

If you want to test if you can refresh 0Auth tokens from ServiceNow Event Manager correctly:

1. Log in to the server that you configured to send events to ServiceNow Event Manager (your central server, a remote server or a poller).
2. Run the following command:

curl -X POST -H "Content-Type: application/x-www-form-urlencoded" 'https://<instance_name>.service-now.com/oauth_token.do' -d 'grant_type=refresh_token&client_id=<client_id>&client_secret=<client_secret>&username=<username>&password=<password>&refresh_token=<refresh_token>'

The <refresh_token> is obtained thanks to this curl.

Sending events

If you want to test that events are sent to ServiceNow Event Manager correctly:

1. Log in to the server that you configured to send events to ServiceNow Event Manager (your central server, a remote server or a poller).
2. Run the following command:

curl -X POST -H 'content-type: application/json' -H 'Accept: application/json' -H 'Authorization: Bearer <access_token>' 'https://<instance_name>.service-now.com/api/global/em/jsonv2' -d '{"records":[{"source": "centreon","event_class": "centreon","severity": 5,"node": "my_host","resource": "my_service","time_of_event": "2022-09-06 11:52:12","description": "CRITICAL: USB cable behaving like a water hose"}]}'

The <access_token> is obtained thanks to this curl.

3. Check that the event has been received by ServiceNow Event Manager.