Nagios not sending emails - email

Question

I want to setup nagios to send email notifications.
I can send email notifications manually clicking the "Send custom service notification" in nagios web interface. The notification is being created and the email is being sent and delivered successfully.
But nagios doesn't send notifications automatically. I have tested it turning off PING service on the machine (echo 1 >/proc/sys/net/ipv4/icmp_echo_ignore_all). Nagios sets PING service to CRITICAL state, but doesn't send notification email.
These are my config files:
Part of templates.cfg
define contact{
name generic-contact ; The name of this contact template
service_notification_period 24x7 ; service notifications can be sent anytime
host_notification_period 24x7 ; host notifications can be sent anytime
service_notification_options w,u,c,r,f,s ; send notifications for all service states, flapping events, and scheduled downtime events
host_notification_options d,u,r,f,s ; send notifications for all host states, flapping events, and scheduled downtime events
service_notification_commands notify-service-by-email ; send service notifications via email
host_notification_commands notify-host-by-email ; send host notifications via email
register 0 ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL CONTACT, JUST A TEMPLATE!
}
Part of contacts.cfg
define contact{
contact_name nagiosadmin ; Short name of user
use generic-contact ; Inherit default values from generic-contact template (defined above)
alias Nagios Admin ; Full name of user
service_notification_options w,u,c,r,f,s
host_notification_options d,u,r,f,s
email MY-EMAIL#gmail.com ; <<***** CHANGE THIS TO YOUR EMAIL ADDRESS ******
}
define contactgroup{
contactgroup_name admins
alias Nagios Administrators
members nagiosadmin
}
generic-host_nagios2.cfg
define host{
name generic-host ; The name of this host template
notifications_enabled 1 ; Host notifications are enabled
event_handler_enabled 1 ; Host event handler is enabled
flap_detection_enabled 1 ; Flap detection is enabled
failure_prediction_enabled 1 ; Failure prediction is enabled
process_perf_data 1 ; Process performance data
retain_status_information 1 ; Retain status information across program restarts
retain_nonstatus_information 1 ; Retain non-status information across program restarts
check_command check-host-alive
max_check_attempts 10
notification_interval 1
notification_period 24x7
notification_options d,u,r,f,s
contact_groups admins
register 0 ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL HOST, JUST A TEMPLATE!
}
generic-service_nagios2.cfg
define service{
name generic-service ; The 'name' of this service template
active_checks_enabled 1 ; Active service checks are enabled
passive_checks_enabled 1 ; Passive service checks are enabled/accepted
parallelize_check 1 ; Active service checks should be parallelized (disabling this can lead to major performance problems)
obsess_over_service 1 ; We should obsess over this service (if necessary)
check_freshness 0 ; Default is to NOT check service 'freshness'
notifications_enabled 1 ; Service notifications are enabled
event_handler_enabled 1 ; Service event handler is enabled
flap_detection_enabled 1 ; Flap detection is enabled
failure_prediction_enabled 1 ; Failure prediction is enabled
process_perf_data 1 ; Process performance data
retain_status_information 1 ; Retain status information across program restarts
retain_nonstatus_information 1 ; Retain non-status information across program restarts
notification_interval 1 ; Only send notifications on status change by default.
is_volatile 0
check_period 24x7
normal_check_interval 5
retry_check_interval 1
max_check_attempts 4
notification_period 24x7
notification_options w,u,c,r,f,s
contact_groups admins
register 0 ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL SERVICE, JUST A TEMPLATE!
}
How can I force nagios to send notification emails?

Answer 1

I had a similar issue. It turned out to be a combination of two problems:
1) I was not waiting long enough for the alerts. Add up your normal_check_interval and retry_check_interval*max_check_attempts for services and you'll see that you must wait as long as 9 minutes before getting a notification. Decrease the normal_check_interval and max_check_attempts if you must know about failures of a service faster. Note that with the default Nagios configuration it may be as much as 15 minutes before it will notify you.
2) The default configuration for linux-server is to notify you during workhours, but the server in question was on UTC. Make sure that notification_period variable everywhere is 24x7.
Good luck.

Answer 2

Check the main nagios.cfg file and make sure notifications_enabled=1. Also verify that your base contact template has notifications_enabled=1 as well.

Answer 3

Please also consider the flap_detection_enabled setting. If this setting is enabled and flapping is determined to exist, Nagios will not notify. Flapping is the idea that a service is frequently changing between OK, soft and normal state. During testing, it's often common for a service to "flap" as we test to ensure everything works. Disable the flap_detection_enabled setting in both your host and service config files during testing.