Improved config-changed hook to perform steps according to the config changed

hooks/pg_gw_hooks.py

@@ -14,6 +14,8 @@ from charmhelpers.core.hookenv import (
     config,
 )
 
+from charmhelpers.core.host import service_running
+
 from charmhelpers.fetch import (
     apt_install,
     apt_purge,
@@ -74,30 +76,32 @@ def config_changed():
     This hook is run when a config parameter is changed.
     It also runs on node reboot.
     '''
-    if add_lcm_key():
-        log("PLUMgrid LCM Key added")
-        return 1
     charm_config = config()
+    if charm_config.changed('lcm-ssh-key'):
+        if add_lcm_key():
+            log("PLUMgrid LCM Key added")
     if charm_config.changed('fabric-interfaces'):
         if not fabric_interface_changed():
             log("Fabric interface already set")
-            return 1
+        else:
-    if charm_config.changed('os-data-network'):
+            stop_pg()
-        if charm_config['fabric-interfaces'] == 'MANAGEMENT':
+    if charm_config.changed('external-interfaces'):
-            log('Fabric running on managment network')
+        stop_pg()
-            return 1
+    if (charm_config.changed('install_sources') or
-    stop_pg()
+        charm_config.changed('plumgrid-build') or
-    configure_sources(update=True)
+        charm_config.changed('install_keys') or
-    pkgs = determine_packages()
+            charm_config.changed('iovisor-build')):
-    for pkg in pkgs:
+        stop_pg()
-        apt_install(pkg, options=['--force-yes'], fatal=True)
+        configure_sources(update=True)
-    remove_iovisor()
+        pkgs = determine_packages()
-    load_iovisor()
+        for pkg in pkgs:
+            apt_install(pkg, options=['--force-yes'], fatal=True)
+            remove_iovisor()
+            load_iovisor()
     ensure_mtu()
-    ensure_files()
-    add_lcm_key()
     CONFIGS.write_all()
-    restart_pg()
+    if not service_running('plumgrid'):
+        restart_pg()
 
 
 @hooks.hook('upgrade-charm')

hooks/pg_gw_utils.py

@@ -30,6 +30,7 @@ from charmhelpers.core.host import (
     write_file,
     service_start,
     service_stop,
+    service_running
 )
 from charmhelpers.fetch import (
     apt_cache,
@@ -142,7 +143,17 @@ def restart_pg():
     '''
     stop_pg()
     service_start('plumgrid')
-    time.sleep(30)
+    time.sleep(3)
+    if not service_running('plumgrid'):
+        if service_running('libvirt-bin'):
+            raise ValueError("plumgrid service couldn't be started")
+        else:
+            if service_start('libvirt-bin'):
+                time.sleep(3)
+                if not service_running('plumgrid'):
+                    raise ValueError("plumgrid service couldn't be started")
+            else:
+                raise ValueError("libvirt-bin service couldn't be started")
 
 
 def stop_pg():

unit_tests/test_pg_gw_hooks.py

@@ -70,10 +70,6 @@ class PGGwHooksTests(CharmTestCase):
         self.CONFIGS.write_all.assert_called_with()
         self.restart_pg.assert_called_with()
 
-    def test_config_changed_hook(self):
-        self.add_lcm_key.return_value = 1
-        self._call_hook('config-changed')
-
     def test_stop(self):
         _pkgs = ['plumgrid-lxc', 'iovisor-dkms']
         self._call_hook('stop')