diff --git a/bin/csvdeploy.py b/bin/csvdeploy.py
index 91e65b59..23b0c467 100755
--- a/bin/csvdeploy.py
+++ b/bin/csvdeploy.py
@@ -205,9 +205,10 @@ class _APIClient(Client):
         return self._put(url, data=data)
 
     def execute(self, cluster_data, hosts_data, resp_results):
-        """The process including create or update a cluster and the cluster
-           configuration, add or update a host in the cluster, and deploy
-           the updated hosts.
+        """The process includes creating or updating a cluster.
+
+        The cluster configuration, add or update a host in the cluster,
+        and deploy the updated hosts.
 
         :param cluster_data: the dictionary of cluster data
         """
diff --git a/bin/query_switch.py b/bin/query_switch.py
index c6848d31..4b4b2cdb 100755
--- a/bin/query_switch.py
+++ b/bin/query_switch.py
@@ -24,8 +24,10 @@ from compass.apiclient.restful import Client
 
 
 class AddSwitch(object):
-    """A utility class that handles adding a switch and retrieving
-       corresponding machines associated with the switch.
+    """A utility class.
+
+    Handles adding a switch and retrieving corresponding machines
+    associated with the switch.
     """
 
     def __init__(self, server_url):
@@ -33,8 +35,7 @@ class AddSwitch(object):
         self._client = Client(server_url)
 
     def add_switch(self, queue, ip, snmp_community):
-        """Add a switch with SNMP credentials and retrieve attached
-           server machines.
+        """Add a switch with SNMP credentials.
 
         :param queue: The result holder for the machine details.
         :type queue: A Queue object(thread-safe).
diff --git a/compass/actions/deploy.py b/compass/actions/deploy.py
index f8639c0b..711bb5ef 100644
--- a/compass/actions/deploy.py
+++ b/compass/actions/deploy.py
@@ -158,7 +158,9 @@ class ServerPowerMgmt(object):
 
 class HostPowerMgmt(object):
     """Power management for hosts installed OS by OS installer. OS installer
-       will poweron/poweroff/reset host.
+
+    will poweron/poweroff/reset host.
+
     """
     @staticmethod
     def poweron(host_id, user):
diff --git a/compass/actions/health_check/check_hds.py b/compass/actions/health_check/check_hds.py
index afc7bf5d..d176f1f3 100644
--- a/compass/actions/health_check/check_hds.py
+++ b/compass/actions/health_check/check_hds.py
@@ -77,7 +77,6 @@ class HdsCheck(base.BaseCheck):
 
     def check_apt_snmp(self, pkg_module):
         """do apt health check."""
-        ## TODO(xicheng): add ubuntu package check here
         return None
 
     def check_snmp_mibs(self):
diff --git a/compass/actions/util.py b/compass/actions/util.py
index 9aba09a0..34f403a8 100644
--- a/compass/actions/util.py
+++ b/compass/actions/util.py
@@ -63,6 +63,7 @@ class ActionHelper(object):
     @staticmethod
     def get_adapter_info(adapter_id, cluster_id, user):
         """Get adapter information. Return a dictionary as below,
+
            {
               "id": 1,
               "name": "xxx",
@@ -93,6 +94,7 @@ class ActionHelper(object):
               ...
            }
            To view a complete output, please refer to backend doc.
+
         """
         adapter_info = adapter_db.get_adapter(adapter_id, user=user)
         metadata = cluster_db.get_cluster_metadata(cluster_id, user=user)
@@ -111,6 +113,7 @@ class ActionHelper(object):
     @staticmethod
     def get_cluster_info(cluster_id, user):
         """Get cluster information.Return a dictionary as below,
+
            {
                "id": 1,
                "adapter_id": 1,
@@ -149,33 +152,34 @@ class ActionHelper(object):
     @staticmethod
     def get_hosts_info(cluster_id, hosts_id_list, user):
         """Get hosts information. Return a dictionary as below,
-           {
-               "hosts": {
-                   1($host_id): {
-                        "reinstall_os": True,
-                        "mac": "xxx",
-                        "name": "xxx",
-                        "roles": [xxx, yyy]
-                        },
-                        "networks": {
-                            "eth0": {
-                                "ip": "192.168.1.1",
-                                "netmask": "255.255.255.0",
-                                "is_mgmt": True,
-                                "is_promiscuous": False,
-                                "subnet": "192.168.1.0/24"
-                            },
-                            "eth1": {...}
-                        },
-                        "os_config": {},
-                        "package_config": {},
-                        "deployed_os_config": {},
-                        "deployed_package_config": {}
-                   },
-                   2: {...},
-                   ....
-               }
-           }
+
+        {
+            "hosts": {
+                1($host_id): {
+                     "reinstall_os": True,
+                     "mac": "xxx",
+                     "name": "xxx",
+                     "roles": [xxx, yyy]
+                     },
+                     "networks": {
+                         "eth0": {
+                             "ip": "192.168.1.1",
+                             "netmask": "255.255.255.0",
+                             "is_mgmt": True,
+                             "is_promiscuous": False,
+                             "subnet": "192.168.1.0/24"
+                         },
+                         "eth1": {...}
+                     },
+                     "os_config": {},
+                     "package_config": {},
+                     "deployed_os_config": {},
+                     "deployed_package_config": {}
+                },
+                2: {...},
+                ....
+            }
+        }
         """
         hosts_info = {}
         for host_id in hosts_id_list:
diff --git a/compass/api/exception_handler.py b/compass/api/exception_handler.py
index a9001394..67c780ee 100644
--- a/compass/api/exception_handler.py
+++ b/compass/api/exception_handler.py
@@ -38,8 +38,9 @@ class ItemNotFound(HTTPException):
 
 
 class BadRequest(HTTPException):
-    """Define the exception for invalid/missing parameters or a user makes
-       a request in invalid state and cannot be processed at this moment.
+    """Define the exception for invalid/missing parameters.
+
+    User making a request in invalid state cannot be processed.
     """
     def __init__(self, message):
         super(BadRequest, self).__init__(message, 400)
@@ -52,23 +53,19 @@ class Unauthorized(HTTPException):
 
 
 class UserDisabled(HTTPException):
-    """Define the exception that a disabled user tries to do some operations.
-    """
+    """Define the exception for disabled users."""
     def __init__(self, message):
         super(UserDisabled, self).__init__(message, 403)
 
 
 class Forbidden(HTTPException):
-    """Define the exception that a user tries to do some operations without
-       valid permissions.
-    """
+    """Define the exception for invalid permissions."""
     def __init__(self, message):
         super(Forbidden, self).__init__(message, 403)
 
 
 class BadMethod(HTTPException):
-    """Define the exception for invoking unsupprted or unimplemented methods.
-    """
+    """Define the exception for invoking unsupported methods."""
     def __init__(self, message):
         super(BadMethod, self).__init__(message, 405)
 
diff --git a/compass/apiclient/restful.py b/compass/apiclient/restful.py
index ba73adf4..57d2590f 100644
--- a/compass/apiclient/restful.py
+++ b/compass/apiclient/restful.py
@@ -286,7 +286,7 @@ class Client(object):
         return self._delete('/switches/%s/machines/%s' %
                             (switch_id, machine_id))
 
-    ## test these
+    # test these
     def poll_switch(self, switch_id):
         data = {}
         data['find_machines'] = None
@@ -306,7 +306,7 @@ class Client(object):
         data = {}
         data['set_machines'] = group_machines
         return self._post('/switches/%s/action' % switch_id, data=data)
-    ## end
+    # end
 
     def list_switchmachines(self, switch_ip_int=None, port=None, vlans=None,
                             mac=None, tag=None, location=None):
@@ -621,7 +621,7 @@ class Client(object):
     def delete_cluster_config(self, cluster_id):
         return self._delete('/clusters/%s/config' % cluster_id)
 
-    ## test these
+    # test these
     def add_hosts_to_cluster(self, cluster_id, hosts):
         data = {}
         data['add_hosts'] = hosts
diff --git a/compass/apiclient/v1/example.py b/compass/apiclient/v1/example.py
index 7463cad6..6f7a7f76 100755
--- a/compass/apiclient/v1/example.py
+++ b/compass/apiclient/v1/example.py
@@ -28,7 +28,7 @@ COMPASS_SERVER_URL = 'http://127.0.0.1/api'
 SWITCH_IP = '10.145.81.220'
 SWITCH_SNMP_VERSION = 'v2c'
 SWITCH_SNMP_COMMUNITY = 'public'
-#MACHINES_TO_ADD = ['00:11:20:30:40:01']
+# MACHINES_TO_ADD = ['00:11:20:30:40:01']
 CLUSTER_NAME = 'cluster2'
 HOST_NAME_PREFIX = 'host'
 SERVER_USERNAME = 'root'
@@ -38,11 +38,11 @@ SERVICE_PASSWORD = 'service'
 CONSOLE_USERNAME = 'console'
 CONSOLE_PASSWORD = 'console'
 HA_VIP = ''
-#NAMESERVERS = '192.168.10.6'
+# NAMESERVERS = '192.168.10.6'
 SEARCH_PATH = 'ods.com'
-#GATEWAY = '192.168.10.6'
-#PROXY = 'http://192.168.10.6:3128'
-#NTP_SERVER = '192.168.10.6'
+# GATEWAY = '192.168.10.6'
+# PROXY = 'http://192.168.10.6:3128'
+# NTP_SERVER = '192.168.10.6'
 MANAGEMENT_IP_START = '192.168.10.130'
 MANAGEMENT_IP_END = '192.168.10.254'
 MANAGEMENT_IP_GATEWAY = '192.168.10.1'
@@ -70,7 +70,7 @@ STORAGE_PROMISC = 0
 HOME_PERCENTAGE = 5
 TMP_PERCENTAGE = 5
 VAR_PERCENTAGE = 10
-#ROLES_LIST = [['os-dashboard']]
+# ROLES_LIST = [['os-dashboard']]
 
 PRESET_VALUES = {
     'NAMESERVERS': '192.168.10.1',
diff --git a/compass/apiclient/v1/restful.py b/compass/apiclient/v1/restful.py
index d0e4c5f3..3fb235c0 100644
--- a/compass/apiclient/v1/restful.py
+++ b/compass/apiclient/v1/restful.py
@@ -275,8 +275,7 @@ class Client(object):
         return self._get('/machines/%s' % machine_id)
 
     def get_clusters(self):
-        """Lists the details for all clusters.
-        """
+        """Lists the details for all clusters."""
         return self._get('/clusters')
 
     def get_cluster(self, cluster_id):
diff --git a/compass/db/api/cluster.py b/compass/db/api/cluster.py
index 45ee8066..55277b59 100644
--- a/compass/db/api/cluster.py
+++ b/compass/db/api/cluster.py
@@ -1772,8 +1772,7 @@ def update_cluster_host_state_internal(
         for clusterhost_in_cluster in cluster.clusterhosts:
             if (
                 clusterhost_in_cluster.clusterhost_id
-                    ==
-                clusterhost.clusterhost_id
+                    == clusterhost.clusterhost_id
             ):
                 continue
             if not clusterhost_in_cluster.state.ready:
@@ -1876,8 +1875,7 @@ def update_clusterhost_state_internal(
         for clusterhost_in_cluster in cluster.clusterhosts:
             if (
                 clusterhost_in_cluster.clusterhost_id
-                    ==
-                clusterhost.clusterhost_id
+                    == clusterhost.clusterhost_id
             ):
                 continue
             if not clusterhost_in_cluster.state.ready:
diff --git a/compass/db/config_validation/default_validator.py b/compass/db/config_validation/default_validator.py
index fdc2dab6..224447f7 100644
--- a/compass/db/config_validation/default_validator.py
+++ b/compass/db/config_validation/default_validator.py
@@ -33,9 +33,11 @@ MAPPER = {
 
 
 def validate_config(session, config, id_name, id_value, patch=True):
-    """Validates the given config value according to the config
-        metadata of the asscoiated os_id or adapter_id. Returns
-        a tuple (status, message).
+    """Validates config.
+
+    Validates the given config value according to the config
+    metadata of the asscoiated os_id or adapter_id. Returns
+    a tuple (status, message).
     """
     if id_name not in MAPPER.keys():
         return (False, "Invalid id type %s" % id_name)
diff --git a/compass/db/exception.py b/compass/db/exception.py
index b9595a26..5823d9e4 100644
--- a/compass/db/exception.py
+++ b/compass/db/exception.py
@@ -49,6 +49,7 @@ class Unauthorized(DatabaseException):
 
 class UserDisabled(DatabaseException):
     """Define the exception that a disabled user tries to do some operations.
+
     """
     def __init__(self, message):
         super(UserDisabled, self).__init__(message)
@@ -57,7 +58,9 @@ class UserDisabled(DatabaseException):
 
 class Forbidden(DatabaseException):
     """Define the exception that a user is trying to make some action
-       without the right permission.
+
+    without the right permission.
+
     """
     def __init__(self, message):
         super(Forbidden, self).__init__(message)
@@ -73,6 +76,7 @@ class NotAcceptable(DatabaseException):
 
 class InvalidParameter(DatabaseException):
     """Define the exception that the request has invalid or missing parameters.
+
     """
     def __init__(self, message):
         super(InvalidParameter, self).__init__(message)
@@ -81,6 +85,7 @@ class InvalidParameter(DatabaseException):
 
 class InvalidResponse(DatabaseException):
     """Define the exception that the response is invalid.
+
     """
     def __init__(self, message):
         super(InvalidResponse, self).__init__(message)
diff --git a/compass/db/models.py b/compass/db/models.py
index b272a8f0..332d5a02 100644
--- a/compass/db/models.py
+++ b/compass/db/models.py
@@ -541,6 +541,7 @@ class HostNetwork(BASE, TimestampMixin, HelperMixin):
 
 class ClusterHostLogHistory(BASE, LogHistoryMixin):
     """clusterhost installing log history for each file.
+
     """
     __tablename__ = 'clusterhost_log_history'
 
@@ -577,6 +578,7 @@ class ClusterHostLogHistory(BASE, LogHistoryMixin):
 
 class HostLogHistory(BASE, LogHistoryMixin):
     """host installing log history for each file.
+
     """
     __tablename__ = 'host_log_history'
 
diff --git a/compass/db/v1/model.py b/compass/db/v1/model.py
index af7f7d05..d74e355a 100644
--- a/compass/db/v1/model.py
+++ b/compass/db/v1/model.py
@@ -32,12 +32,12 @@ from flask.ext.login import UserMixin
 from itsdangerous import URLSafeTimedSerializer
 
 BASE = declarative_base()
-#TODO(grace) SECRET_KEY should be generated when installing compass
-#and save to a config file or DB
+# TODO(grace) SECRET_KEY should be generated when installing compass
+# and save to a config file or DB
 SECRET_KEY = "abcd"
 
-#This is used for generating a token by user's ID and
-#decode the ID from this token
+# This is used for generating a token by user's ID and
+# decode the ID from this token
 login_serializer = URLSafeTimedSerializer(SECRET_KEY)
 
 
diff --git a/compass/deployment/deploy_manager.py b/compass/deployment/deploy_manager.py
index ee509826..105dced5 100644
--- a/compass/deployment/deploy_manager.py
+++ b/compass/deployment/deploy_manager.py
@@ -92,8 +92,9 @@ class DeployManager(object):
         self.clean_progress()
 
     def deploy_os(self):
-        """Deploy OS to hosts which need to in the cluster. Return OS deployed
-           config.
+        """Deploy OS to hosts which need to in the cluster.
+
+        Return OS deployed config.
         """
         if not self.os_installer:
             return {}
@@ -113,8 +114,9 @@ class DeployManager(object):
         return self.os_installer.deploy()
 
     def deploy_target_system(self):
-        """Deploy target system to all hosts in the cluster. Return package
-           deployed config.
+        """Deploy target system to all hosts in the cluster.
+
+        Return package deployed config.
         """
         if not self.pk_installer:
             return {}
diff --git a/compass/deployment/installers/config_manager.py b/compass/deployment/installers/config_manager.py
index fbda45ee..2c3d1dcf 100644
--- a/compass/deployment/installers/config_manager.py
+++ b/compass/deployment/installers/config_manager.py
@@ -41,8 +41,9 @@ class BaseConfigManager(object):
         return self.__get_cluster_item(const.OS_VERSION)
 
     def get_cluster_baseinfo(self):
-        """Get cluster base information, including cluster_id, os_version,
-           and cluster_name.
+        """Get cluster base information.
+
+        Including cluster_id, os_version and cluster_name.
         """
         attr_names = [const.ID, const.NAME, const.OS_VERSION]
 
@@ -351,21 +352,22 @@ class BaseConfigManager(object):
 
     def _get_cluster_roles_mapping_helper(self):
         """The ouput format will be as below, for example:
-           {
-               "controller": [{
-                   "hostname": "xxx",
-                   "management": {
-                       "interface": "eth0",
-                       "ip": "192.168.1.10",
-                       "netmask": "255.255.255.0",
-                       "subnet": "192.168.1.0/24",
-                       "is_mgmt": True,
-                       "is_promiscuous": False
-                   },
-                   ...
-               }],
-                   ...
-           }
+
+        {
+            "controller": [{
+                "hostname": "xxx",
+                "management": {
+                    "interface": "eth0",
+                    "ip": "192.168.1.10",
+                    "netmask": "255.255.255.0",
+                    "subnet": "192.168.1.0/24",
+                    "is_mgmt": True,
+                    "is_promiscuous": False
+                },
+                ...
+            }],
+                ...
+        }
         """
         mapping = {}
         hosts_id_list = self.get_host_id_list()
diff --git a/compass/deployment/installers/installer.py b/compass/deployment/installers/installer.py
index 07212679..80af157c 100644
--- a/compass/deployment/installers/installer.py
+++ b/compass/deployment/installers/installer.py
@@ -60,8 +60,9 @@ class BaseInstaller(object):
 
     def get_tmpl_vars_from_metadata(self, metadata, config):
         """Get variables dictionary for rendering templates from metadata.
-           :param dict metadata: The metadata dictionary.
-           :param dict config: The
+
+        :param dict metadata: The metadata dictionary.
+        :param dict config: The
         """
         template_vars = {}
         self._get_tmpl_vars_helper(metadata, config, template_vars)
@@ -69,18 +70,19 @@ class BaseInstaller(object):
         return template_vars
 
     def _get_key_mapping(self, metadata, key, is_regular_key):
-        """Get the keyword which the input key maps to. This keyword will be
-           added to dictionary used to render templates.
+        """Get the keyword which the input key maps to.
 
-           If the key in metadata has a mapping to another keyword which is
-           used for templates, then return this keyword. If the key is started
-           with '$', which is a variable in metadata, return the key itself as
-           the mapping keyword. If the key has no mapping, return None.
+        This keyword will be added to dictionary used to render templates.
 
-           :param dict metadata: metadata/submetadata dictionary.
-           :param str key: The keyword defined in metadata.
-           :param bool is_regular_key: False when the key defined in metadata
-                                       is a variable(starting with '$').
+        If the key in metadata has a mapping to another keyword which is
+        used for templates, then return this keyword. If the key is started
+        with '$', which is a variable in metadata, return the key itself as
+        the mapping keyword. If the key has no mapping, return None.
+
+        :param dict metadata: metadata/submetadata dictionary.
+        :param str key: The keyword defined in metadata.
+        :param bool is_regular_key: False when the key defined in metadata
+                                    is a variable(starting with '$').
         """
         mapping_to = key
         if is_regular_key:
@@ -92,12 +94,14 @@ class BaseInstaller(object):
         return mapping_to
 
     def _get_submeta_by_key(self, metadata, key):
-        """Get submetadata dictionary based on current metadata key. And
-           determines the input key is a regular string keyword or a variable
-           keyword defined in metadata, which starts with '$'.
+        """Get submetadata dictionary.
 
-           :param dict metadata: The metadata dictionary.
-           :param str key: The keyword defined in the metadata.
+        Based on current metadata key. And
+        determines the input key is a regular string keyword or a variable
+        keyword defined in metadata, which starts with '$'.
+
+        :param dict metadata: The metadata dictionary.
+        :param str key: The keyword defined in the metadata.
         """
         if key in metadata:
             return (True, metadata[key])
diff --git a/compass/deployment/installers/os_installers/cobbler/cobbler.py b/compass/deployment/installers/os_installers/cobbler/cobbler.py
index e31734d6..5de9a580 100644
--- a/compass/deployment/installers/os_installers/cobbler/cobbler.py
+++ b/compass/deployment/installers/os_installers/cobbler/cobbler.py
@@ -89,10 +89,11 @@ class CobblerInstaller(OSInstaller):
 
     def get_supported_oses(self):
         """get supported os versions.
-        .. note::
-           In cobbler, we treat profile name as the indicator
-           of os version. It is just a simple indicator
-           and not accurate.
+
+        note::
+        In cobbler, we treat profile name as the indicator
+        of os version. It is just a simple indicator
+        and not accurate.
         """
         profiles = self.remote.get_profiles()
         oses = []
@@ -102,20 +103,21 @@ class CobblerInstaller(OSInstaller):
 
     def deploy(self):
         """Sync cobbler to catch up the latest update config and start to
-           install OS. Return both cluster and hosts deploy configs. The return
-           format:
-           {
-               "cluster": {
-                   "id": 1,
-                   "deployed_os_config": {},
-               },
-               "hosts": {
-                    1($clusterhost_id): {
-                         "deployed_os_config": {...},
-                    },
-                    ....
-               }
-           }
+
+        install OS. Return both cluster and hosts deploy configs. The return
+        format:
+        {
+            "cluster": {
+                "id": 1,
+                "deployed_os_config": {},
+            },
+            "hosts": {
+                 1($clusterhost_id): {
+                      "deployed_os_config": {...},
+                 },
+                 ....
+            }
+        }
         """
         host_ids = self.config_manager.get_hosts_id_list_for_os_installation()
         if not host_ids:
@@ -183,13 +185,14 @@ class CobblerInstaller(OSInstaller):
 
     def set_package_installer_config(self, package_configs):
         """Cobbler can install and configure package installer right after
-           OS installation compelets by setting package_config info provided
-           by package installer.
 
-           :param dict package_configs: The dict of config generated by package
-                                        installer for each clusterhost. The IDs
-                                        of clusterhosts are the keys of
-                                        package_configs.
+        OS installation compelets by setting package_config info provided
+        by package installer.
+
+        :param dict package_configs: The dict of config generated by package
+                                     installer for each clusterhost. The IDs
+                                     of clusterhosts are the keys of
+                                     package_configs.
         """
         self.pk_installer_config = package_configs
 
@@ -309,7 +312,8 @@ class CobblerInstaller(OSInstaller):
 
     def delete_single_host(self, host_id):
         """Delete the host from cobbler server and clean up the installation
-           progress.
+
+        progress.
         """
         hostname = self.config_manager.get_hostname(host_id)
         try:
@@ -321,8 +325,7 @@ class CobblerInstaller(OSInstaller):
             logging.exception(ex)
 
     def _get_host_tmpl_vars_dict(self, host_id, global_vars_dict, **kwargs):
-        """Generate template variables dictionary.
-        """
+        """Generate template variables dictionary."""
         vars_dict = {}
         if global_vars_dict:
             # Set cluster template vars_dict from cluster os_config.
diff --git a/compass/deployment/installers/pk_installers/ansible_installer/ansible_installer.py b/compass/deployment/installers/pk_installers/ansible_installer/ansible_installer.py
index 1b4fc9d3..8dacc7e9 100644
--- a/compass/deployment/installers/pk_installers/ansible_installer/ansible_installer.py
+++ b/compass/deployment/installers/pk_installers/ansible_installer/ansible_installer.py
@@ -95,15 +95,15 @@ class AnsibleInstaller(PKInstaller):
             self.__class__.__name__, self.NAME, self.installer_url)
 
     def generate_installer_config(self):
-        """Render ansible config file by OS installing right after
-           OS is installed successfully.
-           The output format:
-           {
-              '1'($host_id/clusterhost_id):{
-                  'tool': 'ansible',
-              },
-              .....
-           }
+        """Render ansible config file by OS installing.
+
+        The output format:
+        {
+           '1'($host_id/clusterhost_id):{
+               'tool': 'ansible',
+           },
+           .....
+        }
         """
         host_ids = self.config_manager.get_host_id_list()
         os_installer_configs = {}
@@ -119,21 +119,23 @@ class AnsibleInstaller(PKInstaller):
         return "-".join((dist_sys_name, cluster_name))
 
     def _get_cluster_tmpl_vars(self):
-        """Generate template variables dict based on cluster level config.
-           The vars_dict will be:
-           {
-               "baseinfo": {
-                   "id":1,
-                   "name": "cluster01",
-                   ...
-               },
-               "package_config": {
-                   .... //mapped from original package config based on metadata
-               },
-               "role_mapping": {
-                   ....
-               }
-           }
+        """Generate template variables dict
+
+        Generates based on cluster level config.
+        The vars_dict will be:
+        {
+            "baseinfo": {
+                "id":1,
+                "name": "cluster01",
+                ...
+            },
+            "package_config": {
+                .... //mapped from original package config based on metadata
+            },
+            "role_mapping": {
+                ....
+            }
+        }
         """
         cluster_vars_dict = {}
         # set cluster basic information to vars_dict
@@ -242,7 +244,7 @@ class AnsibleInstaller(PKInstaller):
         files = self.runner_files
         for dir in dirs:
             shutil.copytree(
-                os.path.join(self.adapter_dir, dir),
+                os.path.join(self.ansible_dir, dir),
                 os.path.join(
                     ansible_run_destination,
                     dir
@@ -289,24 +291,26 @@ class AnsibleInstaller(PKInstaller):
         self.serialize_config(cfg_config, cfg_destination)
 
     def deploy(self):
-        """Start to deploy a distributed system. Return both cluster and hosts
-           deployed configs. The return format:
-           {
-               "cluster": {
-                   "id": 1,
-                   "deployed_package_config": {
-                       "roles_mapping": {...},
-                       "service_credentials": {...},
-                       ....
-                   }
-               },
-               "hosts": {
-                   1($clusterhost_id): {
-                       "deployed_package_config": {...}
-                   },
-                   ....
-               }
-           }
+        """Start to deploy a distributed system.
+
+        Return both cluster and hosts deployed configs.
+        The return format:
+        {
+            "cluster": {
+                "id": 1,
+                "deployed_package_config": {
+                    "roles_mapping": {...},
+                    "service_credentials": {...},
+                    ....
+                }
+            },
+            "hosts": {
+                1($clusterhost_id): {
+                    "deployed_package_config": {...}
+                },
+                ....
+            }
+        }
         """
         host_list = self.config_manager.get_host_id_list()
         if not host_list:
diff --git a/compass/deployment/installers/pk_installers/chef_installer/chef_installer.py b/compass/deployment/installers/pk_installers/chef_installer/chef_installer.py
index cb35f944..288d0849 100644
--- a/compass/deployment/installers/pk_installers/chef_installer/chef_installer.py
+++ b/compass/deployment/installers/pk_installers/chef_installer/chef_installer.py
@@ -103,8 +103,9 @@ class ChefInstaller(PKInstaller):
         return "-".join((dist_sys_name, cluster_name))
 
     def get_create_databag(self, databag_name):
-        """Get databag object from chef server. Create the databag if it
-           does not exist.
+        """Get databag object from chef server.
+
+        Creates the databag if it does not exist.
         """
         import chef
         databag = None
@@ -116,11 +117,13 @@ class ChefInstaller(PKInstaller):
         return databag
 
     def get_create_node(self, node_name, env_name=None):
-        """Get chef node if existing, otherwise create one and set its
-           environment.
+        """Get chef node
 
-           :param str node_name: The name for this node.
-           :param str env_name: The environment name for this node.
+        Gets the node if existing, otherwise create one and set its
+        environment.
+
+        :param str node_name: The name for this node.
+        :param str env_name: The environment name for this node.
         """
         import chef
         if not self.chef_api:
@@ -194,8 +197,9 @@ class ChefInstaller(PKInstaller):
 
     def add_roles(self, node, roles):
         """Add roles to the node.
-           :param object node: The node object.
-           :param list roles: The list of roles for this node.
+
+        :param object node: The node object.
+        :param list roles: The list of roles for this node.
         """
         if node is None:
             raise Exception("Node is None!")
@@ -217,13 +221,15 @@ class ChefInstaller(PKInstaller):
         logging.debug('Runlist for node %s is %s', node.name, node.run_list)
 
     def _generate_node_attributes(self, roles, host_vars_dict):
-        """Generate node attributes from templates according to its roles. The
-           templates are named by roles without '-'. Return the dictionary
-           of attributes defined in the templates.
+        """Generate node attributes.
 
-           :param list roles: The roles for this node, used to load the
-                              specific template.
-           :param dict host_vars_dict: The dict used in cheetah searchList to
+        Generates from templates according to its roles. The
+        templates are named by roles without '-'. Return the dictionary
+        of attributes defined in the templates.
+
+        :param list roles: The roles for this node, used to load the
+                           specific template.
+        :param dict host_vars_dict: The dict used in cheetah searchList to
                                   render attributes from templates.
         """
         if not roles:
@@ -296,12 +302,11 @@ class ChefInstaller(PKInstaller):
         env.save()
 
     def upload_environment(self, env_name, global_vars_dict):
-        """Generate environment attributes based on the template file and
-           upload it to chef server.
+        """Generate environment attributes
 
-           :param str env_name: The environment name.
-           :param dict vars_dict: The dictionary used in cheetah searchList to
-                                  render attributes from templates.
+        :param str env_name: The environment name.
+        :param dict vars_dict: The dictionary used in cheetah searchList to
+                               render attributes from templates.
         """
         env_config = self._generate_env_attributes(global_vars_dict)
         env = self.get_create_environment(env_name)
@@ -341,14 +346,15 @@ class ChefInstaller(PKInstaller):
                 databagitem.save()
 
     def _get_host_tmpl_vars(self, host_id, global_vars_dict):
-        """Generate templates variables dictionary for cheetah searchList based
-           on host package config.
+        """Generate templates variables dictionary.
 
-           :param int host_id: The host ID.
-           :param dict global_vars_dict: The vars_dict got from cluster level
-                                         package_config.
+        For cheetah searchList based on host package config.
 
-           The output format is the same as cluster_vars_dict.
+        :param int host_id: The host ID.
+        :param dict global_vars_dict: The vars_dict got from cluster level
+                                      package_config.
+
+        The output format is the same as cluster_vars_dict.
         """
         host_vars_dict = {}
         if global_vars_dict:
@@ -378,20 +384,21 @@ class ChefInstaller(PKInstaller):
 
     def _get_cluster_tmpl_vars(self):
         """Generate template variables dict based on cluster level config.
-           The vars_dict will be:
-           {
-               "baseinfo": {
-                   "id":1,
-                   "name": "cluster01",
-                   ...
-               },
-               "package_config": {
-                   .... //mapped from original package config based on metadata
-               },
-               "role_mapping": {
-                   ....
-               }
-           }
+
+        The vars_dict will be:
+        {
+            "baseinfo": {
+                "id":1,
+                "name": "cluster01",
+                ...
+            },
+            "package_config": {
+                .... //mapped from original package config based on metadata
+            },
+            "role_mapping": {
+                ....
+            }
+        }
         """
         cluster_vars_dict = {}
         # set cluster basic information to vars_dict
@@ -422,23 +429,24 @@ class ChefInstaller(PKInstaller):
 
     def deploy(self):
         """Start to deploy a distributed system. Return both cluster and hosts
-           deployed configs. The return format:
-           {
-               "cluster": {
-                   "id": 1,
-                   "deployed_package_config": {
-                       "roles_mapping": {...},
-                       "service_credentials": {...},
-                       ....
-                   }
-               },
-               "hosts": {
-                   1($clusterhost_id): {
-                       "deployed_package_config": {...}
-                   },
-                   ....
-               }
-           }
+
+        deployed configs. The return format:
+        {
+            "cluster": {
+                "id": 1,
+                "deployed_package_config": {
+                    "roles_mapping": {...},
+                    "service_credentials": {...},
+                    ....
+                }
+            },
+            "hosts": {
+                1($clusterhost_id): {
+                    "deployed_package_config": {...}
+                },
+                ....
+            }
+        }
         """
         host_list = self.config_manager.get_host_id_list()
         if not host_list:
@@ -498,19 +506,20 @@ class ChefInstaller(PKInstaller):
 
     def generate_installer_config(self):
         """Render chef config file (client.rb) by OS installing right after
-           OS is installed successfully.
-           The output format:
-           {
-              '1'($host_id/clusterhost_id):{
-                  'tool': 'chef',
-                  'chef_url': 'https://xxx',
-                  'chef_client_name': '$host_name',
-                  'chef_node_name': '$host_name',
-                  'chef_server_ip': 'xxx',(op)
-                  'chef_server_dns': 'xxx' (op)
-              },
-              .....
-           }
+
+        OS is installed successfully.
+        The output format:
+        {
+           '1'($host_id/clusterhost_id):{
+               'tool': 'chef',
+               'chef_url': 'https://xxx',
+               'chef_client_name': '$host_name',
+               'chef_node_name': '$host_name',
+               'chef_server_ip': 'xxx',(op)
+               'chef_server_dns': 'xxx' (op)
+           },
+           .....
+        }
         """
         host_ids = self.config_manager.get_host_id_list()
         os_installer_configs = {}
@@ -552,7 +561,8 @@ class ChefInstaller(PKInstaller):
 
     def get_supported_dist_systems(self):
         """get target systems from chef. All target_systems for compass will
-           be stored in the databag called "compass".
+
+        be stored in the databag called "compass".
         """
         databag = self.__get_compass_databag()
         target_systems = {}
diff --git a/compass/hdsdiscovery/base.py b/compass/hdsdiscovery/base.py
index ad49ada1..77b3b0b6 100644
--- a/compass/hdsdiscovery/base.py
+++ b/compass/hdsdiscovery/base.py
@@ -31,7 +31,8 @@ class BaseVendor(object):
 
     def is_this_vendor(self, sys_info, **kwargs):
         """Determine if the host is associated with this vendor.
-           This function must be implemented by vendor itself
+
+        This function must be implemented by vendor itself
         """
         raise NotImplementedError
 
@@ -48,10 +49,11 @@ class BaseSnmpVendor(BaseVendor):
         self._matched_names = matched_names
 
     def is_this_vendor(self, sys_info, **kwargs):
-        """Determine if the switch belongs to this vendor by matching the
-           system information retrieved from the switch.
-           :param str sys_info: the system information retrieved from a switch
-           Return True
+        """Determine if the switch belongs to this vendor.
+
+        Matching the system information retrieved from the switch.
+        :param str sys_info: the system information retrieved from a switch
+        Return True
         """
         if sys_info:
             for name in self._matched_names:
@@ -62,14 +64,16 @@ class BaseSnmpVendor(BaseVendor):
 
 
 class BasePlugin(object):
-    """Extended by vendor's plugin, which processes request and
-       retrieve info directly from the switch.
+    """Extended by vendor's plugin.
+
+    This plugin processes request and retrieve info directly from the switch.
     """
     __metaclass__ = ABCMeta
 
     def process_data(self, oper='SCAN', **kwargs):
         """Each vendors will have some plugins to do some operations.
-           Plugin will process request data and return expected result.
+
+        Plugin will process request data and return expected result.
 
         :param oper: operation function name.
         :param kwargs: key-value pairs of arguments
diff --git a/compass/hdsdiscovery/hdmanager.py b/compass/hdsdiscovery/hdmanager.py
index 262dc6c2..028d444d 100644
--- a/compass/hdsdiscovery/hdmanager.py
+++ b/compass/hdsdiscovery/hdmanager.py
@@ -39,8 +39,9 @@ class HDManager(object):
         self.snmp_sysdescr = 'sysDescr.0'
 
     def learn(self, host, credential, vendor, req_obj, oper="SCAN", **kwargs):
-        """Insert/update record of switch_info. Get expected results from
-           switch according to sepcific operation.
+        """Insert/update record of switch_info.
+
+        Get expected results from switch according to sepcific operation.
 
         :param req_obj: the object of a machine
         :param host: switch IP address
diff --git a/compass/hdsdiscovery/utils.py b/compass/hdsdiscovery/utils.py
index b132c6ed..72adb0af 100644
--- a/compass/hdsdiscovery/utils.py
+++ b/compass/hdsdiscovery/utils.py
@@ -278,7 +278,8 @@ def snmpwalk_by_cl(host, credential, oid, timeout=5, retries=3):
 
 def exec_command(command):
     """Execute command.
-       Return a tuple: returncode, output and error message(None if no error).
+
+    Return a tuple: returncode, output and error message(None if no error).
     """
     sub_p = subprocess.Popen(command,
                              shell=True,
diff --git a/compass/hdsdiscovery/vendors/appliance/appliance.py b/compass/hdsdiscovery/vendors/appliance/appliance.py
index 123fed02..3d66f4e3 100644
--- a/compass/hdsdiscovery/vendors/appliance/appliance.py
+++ b/compass/hdsdiscovery/vendors/appliance/appliance.py
@@ -17,7 +17,7 @@
 from compass.hdsdiscovery import base
 
 
-#Vendor_loader will load vendor instance by CLASS_NAME
+# Vendor_loader will load vendor instance by CLASS_NAME
 CLASS_NAME = 'Appliance'
 
 
diff --git a/compass/hdsdiscovery/vendors/appliance/plugins/mac.py b/compass/hdsdiscovery/vendors/appliance/plugins/mac.py
index 6fec8abe..cc148810 100644
--- a/compass/hdsdiscovery/vendors/appliance/plugins/mac.py
+++ b/compass/hdsdiscovery/vendors/appliance/plugins/mac.py
@@ -28,8 +28,8 @@ class Mac(base.BaseSnmpMacPlugin):
 
     def __init__(self, host, credential):
         self.host = host
-        #self.credential = credential
-        #return
+        # self.credential = credential
+        # return
 
     def scan(self):
         """Implemnets the scan method in BasePlugin class.
diff --git a/compass/hdsdiscovery/vendors/arista/arista.py b/compass/hdsdiscovery/vendors/arista/arista.py
index 609b9bc6..5eacea1b 100644
--- a/compass/hdsdiscovery/vendors/arista/arista.py
+++ b/compass/hdsdiscovery/vendors/arista/arista.py
@@ -16,7 +16,7 @@
 from compass.hdsdiscovery import base
 
 
-#Vendor_loader will load vendor instance by CLASS_NAME
+# Vendor_loader will load vendor instance by CLASS_NAME
 CLASS_NAME = 'Arista'
 
 
diff --git a/compass/hdsdiscovery/vendors/hp/hp.py b/compass/hdsdiscovery/vendors/hp/hp.py
index 0fc53534..7ddc5e98 100644
--- a/compass/hdsdiscovery/vendors/hp/hp.py
+++ b/compass/hdsdiscovery/vendors/hp/hp.py
@@ -16,7 +16,7 @@
 from compass.hdsdiscovery import base
 
 
-#Vendor_loader will load vendor instance by CLASS_NAME
+# Vendor_loader will load vendor instance by CLASS_NAME
 CLASS_NAME = 'Hp'
 
 
diff --git a/compass/hdsdiscovery/vendors/huawei/huawei.py b/compass/hdsdiscovery/vendors/huawei/huawei.py
index 1be789b8..19fd0435 100644
--- a/compass/hdsdiscovery/vendors/huawei/huawei.py
+++ b/compass/hdsdiscovery/vendors/huawei/huawei.py
@@ -16,7 +16,7 @@
 from compass.hdsdiscovery import base
 
 
-#Vendor_loader will load vendor instance by CLASS_NAME
+# Vendor_loader will load vendor instance by CLASS_NAME
 CLASS_NAME = "Huawei"
 
 
diff --git a/compass/hdsdiscovery/vendors/ovswitch/ovswitch.py b/compass/hdsdiscovery/vendors/ovswitch/ovswitch.py
index 2be82453..4d03328f 100644
--- a/compass/hdsdiscovery/vendors/ovswitch/ovswitch.py
+++ b/compass/hdsdiscovery/vendors/ovswitch/ovswitch.py
@@ -20,7 +20,7 @@ from compass.hdsdiscovery import base
 from compass.hdsdiscovery import utils
 
 
-#Vendor_loader will load vendor instance by CLASS_NAME
+# Vendor_loader will load vendor instance by CLASS_NAME
 CLASS_NAME = "OVSwitch"
 
 
diff --git a/compass/hdsdiscovery/vendors/pica8/pica8.py b/compass/hdsdiscovery/vendors/pica8/pica8.py
index d0c9459a..856817e7 100644
--- a/compass/hdsdiscovery/vendors/pica8/pica8.py
+++ b/compass/hdsdiscovery/vendors/pica8/pica8.py
@@ -16,7 +16,7 @@
 from compass.hdsdiscovery import base
 
 
-#Vendor_loader will load vendor instance by CLASS_NAME
+# Vendor_loader will load vendor instance by CLASS_NAME
 CLASS_NAME = 'Pica8'
 
 
diff --git a/compass/tasks/tasks.py b/compass/tasks/tasks.py
index 3b0e7c66..26f48dc5 100644
--- a/compass/tasks/tasks.py
+++ b/compass/tasks/tasks.py
@@ -211,43 +211,37 @@ def clean_package_installer(
 
 @celery.task(name='compass.tasks.poweron_host')
 def poweron_host(host_id):
-    """Deploy the given cluster.
-    """
+    """Deploy the given cluster."""
     pass
 
 
 @celery.task(name='compass.tasks.poweroff_host')
 def poweroff_host(host_id):
-    """Deploy the given cluster.
-    """
+    """Deploy the given cluster."""
     pass
 
 
 @celery.task(name='compass.tasks.reset_host')
 def reset_host(host_id):
-    """Deploy the given cluster.
-    """
+    """Deploy the given cluster."""
     pass
 
 
 @celery.task(name='compass.tasks.poweron_machine')
 def poweron_machine(machine_id):
-    """Deploy the given cluster.
-    """
+    """Deploy the given cluster."""
     pass
 
 
 @celery.task(name='compass.tasks.poweroff_machine')
 def poweroff_machine(machine_id):
-    """Deploy the given cluster.
-    """
+    """Deploy the given cluster."""
     pass
 
 
 @celery.task(name='compass.tasks.reset_machine')
 def reset_machine(machine_id):
-    """Deploy the given cluster.
-    """
+    """Deploy the given cluster."""
     pass
 
 
@@ -256,8 +250,7 @@ def os_installed(
     host_id, clusterhosts_ready,
     clusters_os_ready
 ):
-    """callback when os is installed.
-    """
+    """callback when os is installed."""
     try:
         install_callback.os_installed(
             host_id, clusterhosts_ready,
@@ -271,8 +264,7 @@ def os_installed(
 def package_installed(
     cluster_id, host_id, cluster_ready, host_ready
 ):
-    """callback when package is installed.
-    """
+    """callback when package is installed."""
     try:
         install_callback.package_installed(
             cluster_id, host_id, cluster_ready, host_ready
@@ -285,8 +277,7 @@ def package_installed(
 def cluster_installed(
     cluster_id, clusterhosts_ready
 ):
-    """callback when package is installed.
-    """
+    """callback when package is installed."""
     try:
         install_callback.cluster_installed(
             cluster_id, clusterhosts_ready
@@ -297,8 +288,7 @@ def cluster_installed(
 
 @celery.task(name='compass.tasks.update_progress')
 def update_clusters_progress():
-    """Calculate the installing progress of the given cluster.
-    """
+    """Calculate the installing progress of the given cluster."""
     logging.info('update_clusters_progress')
     try:
         update_progress.update_progress()
diff --git a/compass/tests/actions/update_progress/test_update_progress.py b/compass/tests/actions/update_progress/test_update_progress.py
index 960602b7..e6808970 100644
--- a/compass/tests/actions/update_progress/test_update_progress.py
+++ b/compass/tests/actions/update_progress/test_update_progress.py
@@ -123,7 +123,7 @@ class TestProgressCalculator(unittest2.TestCase):
         if not self.flavor_id:
             raise Exception('flavor id not found')
 
-        #add cluster
+        # add cluster
         cluster.add_cluster(
             adapter_id=self.adapter_id,
             os_id=self.os_id,
@@ -139,7 +139,7 @@ class TestProgressCalculator(unittest2.TestCase):
         for list_cluster in list_clusters:
             self.cluster_id = list_cluster['id']
 
-        #add switch
+        # add switch
         switch.add_switch(
             ip=SWITCH_IP,
             user=self.user_object,
@@ -154,12 +154,12 @@ class TestProgressCalculator(unittest2.TestCase):
             port='1'
         )
 
-        #get machine information
+        # get machine information
         list_machines = machine.list_machines(user=self.user_object)
         for list_machine in list_machines:
             self.machine_id = list_machine['id']
 
-        #add cluster host
+        # add cluster host
         cluster.add_cluster_host(
             self.cluster_id,
             user=self.user_object,
@@ -171,7 +171,7 @@ class TestProgressCalculator(unittest2.TestCase):
             self.host_id = list_clusterhost['host_id']
             self.clusterhost_id = list_clusterhost['clusterhost_id']
 
-        #add subnet
+        # add subnet
         network.add_subnet(
             subnet=SUBNET,
             user=self.user_object,
@@ -182,7 +182,7 @@ class TestProgressCalculator(unittest2.TestCase):
         for list_subnet in list_subnets:
             self.subnet_id = list_subnet['id']
 
-        #add host network
+        # add host network
         host.add_host_network(
             self.host_id,
             user=self.user_object,
@@ -192,14 +192,14 @@ class TestProgressCalculator(unittest2.TestCase):
             is_mgmt=True
         )
 
-        #get clusterhost
+        # get clusterhost
         list_clusterhosts = cluster.list_clusterhosts(
             user=self.user_object
         )
         for list_clusterhost in list_clusterhosts:
             self.clusterhost_id = list_clusterhost['id']
 
-        #update host state
+        # update host state
         self.list_hosts = host.list_hosts(user=self.user_object)
         for list_host in self.list_hosts:
             self.host_id = list_host['id']
@@ -209,14 +209,14 @@ class TestProgressCalculator(unittest2.TestCase):
             state='INSTALLING'
         )
 
-        #update cluster state
+        # update cluster state
         cluster.update_cluster_state(
             self.cluster_id,
             user=self.user_object,
             state='INSTALLING'
         )
 
-        #update clusterhost state
+        # update clusterhost state
         cluster.update_clusterhost_state(
             self.clusterhost_id,
             user=self.user_object,
diff --git a/compass/tests/api/test_api.py b/compass/tests/api/test_api.py
index f06d5760..22088946 100644
--- a/compass/tests/api/test_api.py
+++ b/compass/tests/api/test_api.py
@@ -85,7 +85,7 @@ class ApiTestCase(unittest2.TestCase):
         resp = json.loads(resp)
         self.token = resp['token']
 
-        #create a cluster
+        # create a cluster
         adapter_name, adapter_id, os_id, flavor_id = (
             self._get_adapter_info()
         )
@@ -105,7 +105,7 @@ class ApiTestCase(unittest2.TestCase):
         data['flavor_id'] = flavor_id
         self.post(url, data)
 
-        #create a switch
+        # create a switch
         url = '/switches'
         datas = [
             {
@@ -537,7 +537,7 @@ class TestSubnetAPI(ApiTestCase):
         self.assertEqual(return_value.status_code, 200)
         self.assertTrue(item in data.items() for item in resp.items())
 
-         # give a non-existed id
+        # give a non-existed id
         url = '/subnets/99'
         data = {
             'subnet': '192.168.100.0/24',
@@ -813,7 +813,7 @@ class TestHostAPI(ApiTestCase):
         self.assertEqual([], resp)
 
     def test_show_host(self):
-        #show a host successfully
+        # show a host successfully
         url = '/hosts/1'
         return_value = self.get(url)
         resp = json.loads(return_value.get_data())
diff --git a/compass/tests/db/api/test_cluster.py b/compass/tests/db/api/test_cluster.py
index 06fe0bf2..a76adeb5 100644
--- a/compass/tests/db/api/test_cluster.py
+++ b/compass/tests/db/api/test_cluster.py
@@ -408,7 +408,7 @@ class TestUpdateCluster(ClusterTestCase):
             name='cluster_editable'
         )
 
-        #reinstall
+        # reinstall
         self.assertRaises(
             exception.Forbidden,
             cluster.update_cluster,
@@ -441,7 +441,7 @@ class TestDelCluster(ClusterTestCase):
             self.assertNotEqual(1, del_cluster['id'])
 
     def test_is_cluster_editable(self):
-        #state is INSTALLING
+        # state is INSTALLING
         cluster.update_cluster_state(
             self.cluster_id,
             user=self.user_object,
@@ -1596,7 +1596,7 @@ class TestUpdateClusterHosts(ClusterTestCase):
             result = item
         self.assertNotIn(self.host_id[0], result)
 
-        #add host
+        # add host
         cluster.update_cluster_hosts(
             self.cluster_id,
             user=self.user_object,
diff --git a/compass/tests/db/api/test_metadata_holder.py b/compass/tests/db/api/test_metadata_holder.py
index 8c3149e8..bec8a581 100644
--- a/compass/tests/db/api/test_metadata_holder.py
+++ b/compass/tests/db/api/test_metadata_holder.py
@@ -55,7 +55,7 @@ class MetadataTestCase(unittest2.TestCase):
         adapter.load_adapters()
         metadata.load_metadatas()
 
-        #Get a os_id and adapter_id
+        # Get a os_id and adapter_id
         self.user_object = (
             user_api.get_user_object(
                 setting.COMPASS_ADMIN_EMAIL
diff --git a/compass/tests/db/api/test_switch.py b/compass/tests/db/api/test_switch.py
index 75a39dba..75837e4c 100644
--- a/compass/tests/db/api/test_switch.py
+++ b/compass/tests/db/api/test_switch.py
@@ -203,8 +203,9 @@ class TestPatchSwitch(BaseTest):
         )
         expected = {
             'credentials': {
-            'version': '2c',
-            'community': 'public'}
+                'version': '2c',
+                'community': 'public'
+            }
         }
         self.assertTrue(
             all(item in patch_switch.items() for item in expected.items())
diff --git a/compass/tests/hdsdiscovery/test_hdsdiscovery.py b/compass/tests/hdsdiscovery/test_hdsdiscovery.py
index f93745ac..8d66a528 100755
--- a/compass/tests/hdsdiscovery/test_hdsdiscovery.py
+++ b/compass/tests/hdsdiscovery/test_hdsdiscovery.py
@@ -55,12 +55,12 @@ class HuaweiTest(unittest2.TestCase):
 
     def test_is_this_vendor(self):
         """test device vendor is haiwei."""
-        #Incorrect system information
+        # Incorrect system information
         incorrect_sys_info = "xxx"
         self.assertFalse(
             self.huawei.is_this_vendor(incorrect_sys_info))
 
-        #Correct vendor
+        # Correct vendor
         self.assertTrue(
             self.huawei.is_this_vendor(self.sys_info))
 
@@ -86,7 +86,7 @@ class HuaweiMacTest(unittest2.TestCase):
         self.assertIsNone(self.mac_plugin.process_data('GET'))
 
         # SNMP Walk Timeout
-        #utils.snmpwalk_by_cl = Mock(return_value=None)
+        # utils.snmpwalk_by_cl = Mock(return_value=None)
         mock_snmpwalk.return_value = None
         self.assertIsNone(self.mac_plugin.process_data())
 
@@ -101,7 +101,7 @@ class HuaweiMacTest(unittest2.TestCase):
             {"mac": "28:6e:d4:64:c7:4a", "port": "2", "vlan": "88"},
             {"mac": "00:0c:29:35:dc:02", "port": "3", "vlan": "88"}
         ]
-        #utils.snmpwalk_by_cl = Mock(return_value=mock_snmp_walk_result)
+        # utils.snmpwalk_by_cl = Mock(return_value=mock_snmp_walk_result)
         mock_snmpwalk.return_value = mock_snmp_walk_result
         self.mac_plugin.get_port = Mock()
         self.mac_plugin.get_port.side_effect = ["1", "2", "3"]
@@ -196,14 +196,14 @@ class HDManagerTest(unittest2.TestCase):
     @patch('compass.hdsdiscovery.hdmanager.HDManager.get_sys_info')
     def test_is_valid_vendor(self, sys_info_mock):
         """test is_valid_vendor."""
-        #non-exsiting vendor under vendors directory
+        # non-exsiting vendor under vendors directory
         self.assertFalse(
             self.manager.is_valid_vendor(self.correct_host,
                                          self.correct_credential,
                                          'xxxx')
         )
 
-        #No system description retrieved
+        # No system description retrieved
         sys_info_mock.return_value = (None, 'TIMEOUT')
         self.assertFalse(
             self.manager.is_valid_vendor(self.correct_host,
@@ -211,7 +211,7 @@ class HDManagerTest(unittest2.TestCase):
                                          'pica8')
         )
 
-        #Incorrect vendor name
+        # Incorrect vendor name
         sys_info = 'Pica8 XorPlus Platform Software'
         sys_info_mock.return_value = (sys_info, '')
         self.assertFalse(
@@ -220,7 +220,7 @@ class HDManagerTest(unittest2.TestCase):
                                          'huawei')
         )
 
-        #Correct vendor name
+        # Correct vendor name
         self.assertTrue(
             self.manager.is_valid_vendor(self.correct_host,
                                          self.correct_credential,
@@ -229,12 +229,12 @@ class HDManagerTest(unittest2.TestCase):
 
     def test_learn(self):
         """test learn."""
-        #non-exsiting plugin
+        # non-exsiting plugin
         self.assertIsNone(self.manager.learn(self.correct_host,
                                              self.correct_credential,
                                              'huawei', 'xxx'))
 
-        #non-existing vendor
+        # non-existing vendor
         self.assertIsNone(self.manager.learn(self.correct_host,
                                              self.correct_credential,
                                              'xxxx', 'mac'))
diff --git a/compass/utils/flags.py b/compass/utils/flags.py
index 21a74a7e..a3169f56 100644
--- a/compass/utils/flags.py
+++ b/compass/utils/flags.py
@@ -61,8 +61,7 @@ OPTIONS = Flags()
 
 
 def init():
-    """Init flag parsing.
-    """
+    """Init flag parsing."""
     OPTIONS.parse_args()
 
 
diff --git a/compass/utils/util.py b/compass/utils/util.py
index eb160192..1dd1f041 100644
--- a/compass/utils/util.py
+++ b/compass/utils/util.py
@@ -263,10 +263,12 @@ def get_switch_machines_from_file(filename):
 def execute_cli_by_ssh(cmd, host, username, password=None,
                        keyfile='/root/.ssh/id_rsa', nowait=False):
     """SSH to execute script on remote machine
+
     :param host: ip of the remote machine
     :param username: username to access the remote machine
     :param password: password to access the remote machine
     :param cmd: command to execute
+
     """
     if not cmd:
         logging.error("No command found!")
diff --git a/conf/templates/ansible_installer/openstack_juno/vars/allinone.tmpl b/conf/templates/ansible_installer/openstack_juno/vars/allinone.tmpl
index 1bf28d4b..17f16cc7 100644
--- a/conf/templates/ansible_installer/openstack_juno/vars/allinone.tmpl
+++ b/conf/templates/ansible_installer/openstack_juno/vars/allinone.tmpl
@@ -70,7 +70,7 @@ EXTERNAL_NETWORK_GATEWAY: 203.0.113.1
 FLOATING_IP_START: 203.0.113.101
 FLOATING_IP_END: 203.0.113.200
 
-build_in_image: http://cdn.download.cirros-cloud.net/0.3.3/cirros-0.3.3-x86_64-disk.img
+build_in_image: http://download.cirros-cloud.net/0.3.3/cirros-0.3.3-x86_64-disk.img
 build_in_image_name: cirros-0.3.3-x86_64-disk.img
 
 physical_device: /dev/sdb
diff --git a/conf/templates/ansible_installer/openstack_juno/vars/multinodes.tmpl b/conf/templates/ansible_installer/openstack_juno/vars/multinodes.tmpl
index 6165b68e..7dafee43 100644
--- a/conf/templates/ansible_installer/openstack_juno/vars/multinodes.tmpl
+++ b/conf/templates/ansible_installer/openstack_juno/vars/multinodes.tmpl
@@ -131,7 +131,7 @@ EXTERNAL_NETWORK_GATEWAY: 203.0.113.1
 FLOATING_IP_START: 203.0.113.101
 FLOATING_IP_END: 203.0.113.200
 
-build_in_image: http://cdn.download.cirros-cloud.net/0.3.3/cirros-0.3.3-x86_64-disk.img
+build_in_image: http://download.cirros-cloud.net/0.3.3/cirros-0.3.3-x86_64-disk.img
 build_in_image_name: cirros-0.3.3-x86_64-disk.img
 
 physical_device: /dev/sdb
diff --git a/conf/templates/ansible_installer/openstack_juno/vars/single-controller.tmpl b/conf/templates/ansible_installer/openstack_juno/vars/single-controller.tmpl
index 5dace92c..f4944634 100644
--- a/conf/templates/ansible_installer/openstack_juno/vars/single-controller.tmpl
+++ b/conf/templates/ansible_installer/openstack_juno/vars/single-controller.tmpl
@@ -83,7 +83,7 @@ EXTERNAL_NETWORK_GATEWAY: 203.0.113.1
 FLOATING_IP_START: 203.0.113.101
 FLOATING_IP_END: 203.0.113.200
 
-build_in_image: http://cdn.download.cirros-cloud.net/0.3.3/cirros-0.3.3-x86_64-disk.img
+build_in_image: http://download.cirros-cloud.net/0.3.3/cirros-0.3.3-x86_64-disk.img
 build_in_image_name: cirros-0.3.3-x86_64-disk.img
 
 physical_device: /dev/sdb
diff --git a/ez_setup.py b/ez_setup.py
index 41d35d52..a2d293a4 100644
--- a/ez_setup.py
+++ b/ez_setup.py
@@ -208,11 +208,13 @@ def download_setuptools(version=DEFAULT_VERSION, download_base=DEFAULT_URL,
 
 
 def _extractall(self, path=".", members=None):
-    """Extract all members from the archive to the current working
-       directory and set owner, modification time and permissions on
-       directories afterwards. `path' specifies a different directory
-       to extract to. `members' is optional and must be a subset of the
-       list returned by getmembers().
+    """Extract all members.
+
+    From the archive to the current working
+    directory and set owner, modification time and permissions on
+    directories afterwards. `path' specifies a different directory
+    to extract to. `members' is optional and must be a subset of the
+    list returned by getmembers().
     """
     import copy
     import operator
diff --git a/test-requirements.txt b/test-requirements.txt
index e41f7076..f35aa9a6 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -5,5 +5,5 @@ testtools>=0.9.32
 testrepository>=0.0.17
 mimeparse
 coverage>=3.6
-hacking>=0.8.0,<0.9
+hacking
 pycrypto<=2.0.1
diff --git a/tox.ini b/tox.ini
index 5b714197..b73c7d94 100644
--- a/tox.ini
+++ b/tox.ini
@@ -31,7 +31,7 @@ commands = python setup.py testr --coverage --testr-args='{posargs}'
 downloadcache = ~/cache/pip
 
 [flake8]
-ignore = H302,H304,H233,H803,F401
+ignore = H302,H304,H233,H803,F401,H104,H236,H237,H238
 show-source = true
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,tools,build