Addressed reviews by Charmers

hooks/pg_dir_hooks.py

@@ -1,13 +1,22 @@
 #!/usr/bin/python
 
+# Copyright (c) 2015, PLUMgrid Inc, http://plumgrid.com
+
+# The hooks of this charm have been symlinked to functions
+# in this file.
+
 import sys
 
 from charmhelpers.core.hookenv import (
     Hooks,
     UnregisteredHookError,
-    config,
     log,
-    relation_set,
+)
+
+from charmhelpers.fetch import (
+    apt_install,
+    apt_purge,
+    configure_sources,
 )
 
 from pg_dir_utils import (
@@ -15,6 +24,11 @@ from pg_dir_utils import (
     ensure_files,
     restart_pg,
     stop_pg,
+    determine_packages,
+    load_iovisor,
+    remove_iovisor,
+    ensure_mtu,
+    add_lcm_key,
 )
 
 hooks = Hooks()
@@ -23,28 +37,61 @@ CONFIGS = register_configs()
 
 @hooks.hook()
 def install():
+    '''
+    Install hook is run when the charm is first deployed on a node.
+    '''
+    configure_sources(update=True)
+    pkgs = determine_packages()
+    for pkg in pkgs:
+        apt_install(pkg, options=['--force-yes'], fatal=True)
+    load_iovisor()
+    ensure_mtu()
     ensure_files()
+    add_lcm_key()
 
 
 @hooks.hook('plumgrid-plugin-relation-joined')
 def plumgrid_dir():
+    '''
+    This hook is run when relation between neutron-api-plumgrid
+    and plumgrid-director is made.
+    '''
+    ensure_mtu()
     ensure_files()
+    add_lcm_key()
     CONFIGS.write_all()
     restart_pg()
 
 
-@hooks.hook('plumgrid-relation-joined')
-def plumgrid_joined(relation_id=None):
-    #We can pass information to the edge and gateway from there.
-    relation_data = {
-        'pg_virtual_ip': config('plumgrid-virtual-ip'),
-    }
-    relation_set(relation_id=relation_id, **relation_data)
+@hooks.hook('config-changed')
+def config_changed():
+    '''
+    This hook is run when a config parameter is changed.
+    It also runs on node reboot.
+    '''
+    stop_pg()
+    configure_sources(update=True)
+    pkgs = determine_packages()
+    for pkg in pkgs:
+        apt_install(pkg, options=['--force-yes'], fatal=True)
+    load_iovisor()
+    ensure_mtu()
+    ensure_files()
+    add_lcm_key()
+    CONFIGS.write_all()
+    restart_pg()
 
 
 @hooks.hook('stop')
 def stop():
+    '''
+    This hook is run when the charm is destroyed.
+    '''
     stop_pg()
+    remove_iovisor()
+    pkgs = determine_packages()
+    for pkg in pkgs:
+        apt_purge(pkg, fatal=False)
 
 
 def main():