PagerDuty webhooks email script for Nagios.

pagerduty_nagios_webhooks.php

<?php
//Nagios alerts with a custom subject line that includes the HOSTNAME, SERVICESTATE, SERVICEDESC, HOSTSTATE and PagerDuty incident status fields.
$messages = json_decode($HTTP_RAW_POST_DATA); 
if ($messages) foreach ($messages->messages as $webhook) {
  $service = $webhook->data->incident->service->name;
  $description = $webhook->data->incident->trigger_summary_data->subject." ".$webhook->data->incident->trigger_summary_data->description;
  $status = $webhook->data->incident->status;
  $link = $webhook->data->incident->html_url;
  $emailAddress = ($webhook->type == "incident.resolve" ? $webhook->data->incident->last_status_change_by->email : $webhook->data->incident->assigned_to_user->email);
  $body = "PagerDuty Update\n\nAn incident has been $status.\n\nDetails: $description on service $service\n\nClick here for more details:  $link\n";
  $subject = "[" . $webhook->data->incident->trigger_summary_data->HOSTNAME . "/"
        . $webhook->data->incident->trigger_summary_data->SERVICESTATE . "/"
        . $webhook->data->incident->trigger_summary_data->SERVICEDESC . "/"
        . $webhook->data->incident->trigger_summary_data->HOSTSTATE . "] "
        . $webhook->data->incident->status;
  $success = mail($emailAddress, $subject, $body);
  if (!$success) {
    mail($emailAddress, "Mail failed", "Mail failed");
  }
}
?>