[bradm] Added support to get nagios hostname from nrpe relation

hooks/charmhelpers/contrib/charmsupport/nrpe.py

@@ -129,6 +129,7 @@ define service {{
             os.path.join(os.environ['CHARM_DIR'],
                          'files/nrpe-external-master'),
             '/usr/lib/nagios/plugins',
+            '/usr/local/lib/nagios/plugins',
         )
         parts = shlex.split(check_cmd)
         for path in search_path:
@@ -181,12 +182,15 @@ class NRPE(object):
     nagios_exportdir = '/var/lib/nagios/export'
     nrpe_confdir = '/etc/nagios/nrpe.d'
 
-    def __init__(self):
+    def __init__(self, hostname=None):
         super(NRPE, self).__init__()
         self.config = config()
         self.nagios_context = self.config['nagios_context']
         self.unit_name = local_unit().replace('/', '-')
-        self.hostname = "{}-{}".format(self.nagios_context, self.unit_name)
+        if hostname:
+            self.hostname = hostname
+        else:
+            self.hostname = "{}-{}".format(self.nagios_context, self.unit_name)
         self.checks = []
 
     def add_check(self, *args, **kwargs):

hooks/horizon_hooks.py

@@ -10,6 +10,7 @@ from charmhelpers.core.hookenv import (
     relation_set,
     relation_get,
     relation_ids,
+    relations_of_type,
     unit_get
 )
 from charmhelpers.fetch import (
@@ -193,7 +194,14 @@ def website_relation_joined():
 
 @hooks.hook('nrpe-external-master-relation-joined', 'nrpe-external-master-relation-changed')
 def update_nrpe_config():
-    nrpe_compat = nrpe.NRPE()
+    # Find out if nrpe set nagios_hostname
+    hostname = None
+    for rel in relations_of_type('nrpe-external-master'):
+        if 'nagios_hostname' in rel:
+            hostname = rel['nagios_hostname']
+            break
+    nrpe_compat = nrpe.NRPE(hostname=hostname)
+
     conf = nrpe_compat.config
     check_http_params = conf.get('nagios_check_http_params')
     if check_http_params: