In this recipe, we'll learn how to automatically arrange notifications so that they are only received by certain contacts in a group at certain times.
For companies with more than one person as dedicated network staff, it's common practice to have an on-call roster, where one member of staff will be the dedicated on-call person for a certain period of time, perhaps a week or two. The kind of setup we'll configure here allows filtering notifications so that they're only delivered to the contacts at appropriate times; notifications are generated by hosts and services and sent to all the contacts in the nominated group, but only one (or perhaps more than one) of the contacts actually receives it.
We'll set this up using two properties of contacts that allow us to restrict the time period within which they should receive notifications: host_notification_period and service_notification_period.
You should have a Nagios Core 4.0 or newer server, with at least one contact group configured already, and with at least two contacts within it. You should be familiar with configuring time periods and understand the basics of notifications as discussed earlier in this chapter.
We'll use the very simple example of three network operators, named as contacts alan, brenden, and charlotte, taking turns with monitoring duty every week. All three are members of the group ops, which is specified in the contact_groups directive for all the hosts and services on the network.
We can set up a basic alternating schedule for receiving notifications for our operators as follows:
- Change to the objects configuration directory for Nagios Core. The default is
/usr/local/nagios/etc/objects. If you've put the definition for your host in a different file, move to that directory instead.# cd /usr/local/nagios/etc/objects - Check the relevant file or files to ensure your contacts are defined and that they are members of the appropriate contact group. A good location for such information is in the
contacts.cfgfile.define contactgroup { contactgroup_name ops alias Network Operations members alan,brenden,charlotte } define contact { use generic-contact contact_name alan alias Alan Jones email [email protected] } define contact { use generic-contact contact_name brenden alias Brenden Peters email [email protected] } define contact { use generic-contact contact_name charlotte alias Charlotte Franks email [email protected] } - In this case, all our hosts and services are configured to send messages to the ops contact group:
define host { ... contact_groups ops } define service { ... contact_groups ops } - Define time periods to correspond to the times during which each of your contacts should be receiving messages. We'll use the special syntax of time period definitions to set up the definitions for this rotation:
define timeperiod { timeperiod_name alan-pager alias Alan pager schedule 2015-12-05 / 21 00:00-24:00 2015-12-06 / 21 00:00-24:00 2015-12-07 / 21 00:00-24:00 2015-12-08 / 21 00:00-24:00 2015-12-09 / 21 00:00-24:00 2015-12-10 / 21 00:00-24:00 2015-12-11 / 21 00:00-24:00 } define timeperiod { timeperiod_name brenden-pager alias Brenden pager schedule 2015-12-12 / 21 00:00-24:00 2015-12-13 / 21 00:00-24:00 2015-12-14 / 21 00:00-24:00 2015-12-15 / 21 00:00-24:00 2015-12-16 / 21 00:00-24:00 2015-12-17 / 21 00:00-24:00 2015-12-18 / 21 00:00-24:00 } define timeperiod { timeperiod_name charlotte-pager alias Charlotte pager schedule 2015-12-19 / 21 00:00-24:00 2015-12-20 / 21 00:00-24:00 2015-12-21 / 21 00:00-24:00 2015-12-22 / 21 00:00-24:00 2015-12-23 / 21 00:00-24:00 2015-12-24 / 21 00:00-24:00 2015-12-25 / 21 00:00-24:00 } - Go back, and configure each of your contacts with the
host_notification_periodandservice_notification_perioddirectives to filter notifications to be received only during their dedicated time period:define contact { use generic-contact contact_name alan alias Alan Jones email [email protected] host_notification_period alan-pager service_notification_period alan-pager } define contact { use generic-contact contact_name brenden alias Brenden Peters email [email protected] host_notification_period brenden-pager service_notification_period brenden-pager } define contact { use generic-contact contact_name charlotte alias Charlotte Franks email [email protected] host_notification_period charlotte-pager service_notification_period charlotte-pager } - Validate the configuration and restart the Nagios Core server:
# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg # /etc/init.d/nagios reload
With this done, the contacts configured should receive notifications only during their dedicated pager time. If these are our only contacts, then all the notifications generated will go to only one person at any given time.
The host_notification_period and service_notification_period directives in the definitions for our contacts are used to limit the times during which these contacts should receive any notifications. Each of our contacts in this example has their own time period defined to correspond to their portion of the pager schedule.
Let's take a look at Alan's example:
define timeperiod {
timeperiod_name alan-pager
2015-12-05 / 21 00:00-24:00
2015-12-06 / 21 00:00-24:00
2015-12-07 / 21 00:00-24:00
2015-12-08 / 21 00:00-24:00
2015-12-09 / 21 00:00-24:00
2015-12-10 / 21 00:00-24:00
2015-12-11 / 21 00:00-24:00
}The second line of the directive, 2015-12-05 / 21 00:00-24:00, can be broken down as follows:
- Starting from the 5th of December
- Every 21 days,
- From midnight to the following midnight (that is, the entire day)
The configuration then goes on to do the same for the remaining days of the first week when Alan will be on call and specifies that he will be on call the same day 21 days (three weeks) later. A similar configuration, but starting one week and two weeks later, is set up for the contacts brenden and charlotte respectively.
Note that there's no reason time periods can't overlap. If it happens to suit us to arrange for more than one contact to receive a notification, we can do that. Similarly, we can leave gaps in the schedule if notifications aren't needed during a certain time period.
Time periods in Nagios Core are highly flexible; to see some examples of the various syntaxes you can use for defining them, take a look at the "Creating a new time period" recipe in Chapter 1, Understanding Hosts, Services, and Contacts.
- Creating a new contact, Chapter 1, Understanding Hosts, Services, and Contacts
- Creating a new contact group, Chapter 1, Understanding Hosts, Services, and Contacts
- The Configuring notifications for groups section in this chapter
- Creating a new time period, Chapter 1, Understanding Hosts, Services, and Contacts
- The Choosing states for notification section in this chapter