Nagios3 check_httpname gives 503 response; from command line I get a 200 response

Question

We're using Nagios to monitor our site (and a bunch of other stuff.) For some odd reason, when I test out the command

/usr/lib/nagios/plugins/check_http -H 'domainname.com'

the response that comes back is HTTP/1.1 200 OK but when I set up the service to do it:

# Check that domain is running
define service {
    hostgroup_name                  hostgroup
    service_description             host site
    check_command                   check_httpname!domainname.com
    use                             generic-service
    notification_interval           1; set > 0 if you want to be renotified
}

the response that comes back is HTTP/1.1 503 Service Unavailable.

Does anyone know why this would be happening?

Answer 1

Not sure why I can't add a comment but can you might want to verify your address and host_name in the host definition. I've been stuck in situations where the command line check script works but the GUI is telling me something else. Usually it's a typo in the address field.