diff --git a/README.md b/README.md
new file mode 100644
index 0000000..498bce1
--- /dev/null
+++ b/README.md
@@ -0,0 +1,7 @@
+Overview
+--------
+
+This charm provides the Ceilometer Compute Agent for OpenStack. 
+It must be deployed in each nova-compute node.
+See Ceilometer charm (lp:~yolanda.robla/charms/precise/ceilometer/trunk) 
+for usage details.
diff --git a/hooks/ceilometer_utils.py b/hooks/ceilometer_utils.py
index 24445e8..ff2012e 100644
--- a/hooks/ceilometer_utils.py
+++ b/hooks/ceilometer_utils.py
@@ -1,6 +1,11 @@
 import os
 import uuid
 
-NOVA_CONF="/etc/nova/nova.conf"
-CEILOMETER_CONF="/etc/ceilometer/ceilometer.conf"
+NOVA_CONF = "/etc/nova/nova.conf"
+CEILOMETER_CONF = "/etc/ceilometer/ceilometer.conf"
 CEILOMETER_COMPUTE_SERVICES = ['ceilometer-agent-compute']
+CEILOMETER_PACKAGES = ['ceilometer-common', 'ceilometer-agent-compute']
+NOVA_SETTINGS = ['instance_usage_audit=True',
+    'instance_usage_audit_period=hour',
+    'notification_driver=nova.openstack.common.notifier.rabbit_notifier',
+    'notification_driver=ceilometer.compute.nova_notifier']
diff --git a/hooks/hooks.py b/hooks/hooks.py
index 043da50..8cef934 100755
--- a/hooks/hooks.py
+++ b/hooks/hooks.py
@@ -6,50 +6,56 @@ import os
 import utils
 import ceilometer_utils
 
+
 def install():
     utils.configure_source()
-    packages = ['ceilometer-common', 'ceilometer-agent-compute']
-    utils.install(*packages)
-
-def container_joined():
-    utils.modify_config_file(ceilometer_utils.NOVA_CONF)
+    utils.install(*ceilometer_utils.CEILOMETER_PACKAGES)
+    utils.modify_config_file(ceilometer_utils.NOVA_CONF,
+        *ceilometer_utils.NOVA_SETTINGS)
     utils.restart(*ceilometer_utils.CEILOMETER_COMPUTE_SERVICES)
 
-def ceilometer_joined():
-    pass
 
 def get_ceilometer_conf():
     for relid in utils.relation_ids('ceilometer-service'):
         for unit in utils.relation_list(relid):
             conf = {
-                'metering_secret': utils.relation_get('metering_secret', unit, relid),
+                'metering_secret': utils.relation_get('metering_secret',
+                    unit, relid),
                 'rabbit_host': utils.relation_get('rabbit_host', unit, relid),
-                'rabbit_virtual_host': utils.relation_get('rabbit_virtual_host', unit, relid),
-                'rabbit_userid': utils.relation_get('rabbit_userid', unit, relid),
-                'rabbit_password': utils.relation_get('rabbit_password', unit, relid),
-                'keystone_os_username': utils.relation_get('keystone_os_username', unit, relid),
-                'keystone_os_password': utils.relation_get('keystone_os_password', unit, relid),
-                'keystone_os_tenant': utils.relation_get('keystone_os_tenant', unit, relid),
-                'keystone_host': utils.relation_get('keystone_host', unit, relid),
-                'keystone_port': utils.relation_get('keystone_port', unit, relid)
+                'rabbit_virtual_host': utils.relation_get(
+                    'rabbit_virtual_host', unit, relid),
+                'rabbit_userid': utils.relation_get('rabbit_userid',
+                    unit, relid),
+                'rabbit_password': utils.relation_get('rabbit_password',
+                    unit, relid),
+                'keystone_os_username': utils.relation_get(
+                    'keystone_os_username', unit, relid),
+                'keystone_os_password': utils.relation_get(
+                    'keystone_os_password', unit, relid),
+                'keystone_os_tenant': utils.relation_get('keystone_os_tenant',
+                    unit, relid),
+                'keystone_host': utils.relation_get('keystone_host',
+                    unit, relid),
+                'keystone_port': utils.relation_get('keystone_port',
+                    unit, relid)
             }
 
             if None not in conf.itervalues():
                 return conf
     return None
 
+
 def ceilometer_changed():
     # read settings
     context = get_ceilometer_conf()
     if context:
         with open(ceilometer_utils.CEILOMETER_CONF, "w") as conf:
-            conf.write(utils.render_template(os.path.basename(ceilometer_utils.CEILOMETER_CONF), context))
+            conf.write(utils.render_template(os.path.basename(
+                ceilometer_utils.CEILOMETER_CONF), context))
             utils.restart(*ceilometer_utils.CEILOMETER_COMPUTE_SERVICES)
 
 utils.do_hooks({
     "install": install,
-    "container-relation-joined": container_joined,
-    "ceilometer-service-relation-joined": ceilometer_joined,
     "ceilometer-service-relation-changed": ceilometer_changed
 })
 sys.exit(0)
diff --git a/hooks/lib/openstack_common.py b/hooks/lib/openstack_common.py
index c9cbb3b..e686399 100644
--- a/hooks/lib/openstack_common.py
+++ b/hooks/lib/openstack_common.py
@@ -11,7 +11,7 @@ ubuntu_openstack_release = {
     'oneiric': 'diablo',
     'precise': 'essex',
     'quantal': 'folsom',
-    'raring' : 'grizzly'
+    'raring': 'grizzly'
 }
 
 
@@ -67,6 +67,7 @@ def get_os_codename_install_source(src):
             if v in src:
                 return v
 
+
 def get_os_codename_version(vers):
     '''Determine OpenStack codename from version number.'''
     try:
@@ -142,7 +143,7 @@ def configure_installation_source(rel):
         subprocess.check_call(["add-apt-repository", "-y", src])
     elif rel[:3] == "deb":
         l = len(rel.split('|'))
-        if l ==  2:
+        if l == 2:
             src, key = rel.split('|')
             juju_log("Importing PPA key from keyserver for %s" % src)
             _import_key(key)
@@ -166,7 +167,8 @@ def configure_installation_source(rel):
 
         if ca_rel == 'folsom/staging':
             # staging is just a regular PPA.
-            cmd = 'add-apt-repository -y ppa:ubuntu-cloud-archive/folsom-staging'
+            cmd = 'add-apt-repository -y '\
+                'ppa:ubuntu-cloud-archive/folsom-staging'
             subprocess.check_call(cmd.split(' '))
             return
 
diff --git a/hooks/utils.py b/hooks/utils.py
index d7cbc0c..01306ad 100644
--- a/hooks/utils.py
+++ b/hooks/utils.py
@@ -134,26 +134,21 @@ def get_os_version(package=None):
     else:
         return None
 
-def modify_config_file(nova_conf):
-    f = open(nova_conf, 'r')
-    data = f.readlines()
-    f.close()
+def modify_config_file(nova_conf, values):
+    try:
+        config = ConfigParser.ConfigParser()
+        f = open(nova_conf, "r+")
+        config.readfp(f)
 
-    # if lines are not in the script, add there
-    contents = ['instance_usage_audit=True', 'instance_usage_audit_period=hour', 'notification_driver=nova.openstack.common.notifier.rabbit_notifier',
-        'notification_driver=ceilometer.compute.nova_notifier']
-    for content in contents:
-        found = False
-        for line in data:
-            if content in line:
-                found = True
-                break
+        # add needed config lines - tuple with section,key,value
+        for value in values:
+            config.set(value[0], value[1], value[2])
+        config.write()
 
-        # not found it, write and continue
-        if not found:
-            f1 = open(nova_conf, 'a')
-            f1.write(content+"\n")
-            f1.close()
+        f.close()
+    except IOError as e:
+        juju_log('ERROR', 'nova config file must exist at this point')
+        sys.exit(1)
 
 def relation_ids(relation):
     cmd = [
diff --git a/readme b/readme
deleted file mode 100644
index caec721..0000000
--- a/readme
+++ /dev/null
@@ -1,17 +0,0 @@
-Overview
---------
-
-This charm provides the Ceilometer service for OpenStack.  It is intended to
-be used alongside the other OpenStack components, starting with the Folsom
-release.
-
-Ceilometer is made up of 2 separate services: an API service, and a collector 
-service. This charm allows them to be deployed in different
-combination, depending on user preference and requirements.
-
-This charm was developed to support deploying Folsom on both
-Ubuntu Quantal and Ubuntu Precise.  Since Ceilometer is only available for
-Ubuntu 12.04 via the Ubuntu Cloud Archive, deploying this charm to a
-Precise machine will by default install Ceilometer and its dependencies from
-the Cloud Archive.
-