diff --git a/n2vc/n2vc_conn.py b/n2vc/n2vc_conn.py
index 6819335..c0bb558 100644
--- a/n2vc/n2vc_conn.py
+++ b/n2vc/n2vc_conn.py
@@ -23,25 +23,26 @@
 
 import abc
 import asyncio
-import os
-import subprocess
-import shlex
-import time
 from enum import Enum
 from http import HTTPStatus
-from n2vc.loggable import Loggable
+import os
+import shlex
+import subprocess
+import time
+
 from n2vc.exceptions import N2VCBadArgumentsException
+from osm_common.dbmongo import DbException
 import yaml
 
-from osm_common.dbmongo import DbException
+from n2vc.loggable import Loggable
 
 
 class N2VCDeploymentStatus(Enum):
-    PENDING = 'pending'
-    RUNNING = 'running'
-    COMPLETED = 'completed'
-    FAILED = 'failed'
-    UNKNOWN = 'unknown'
+    PENDING = "pending"
+    RUNNING = "running"
+    COMPLETED = "completed"
+    FAILED = "failed"
+    UNKNOWN = "unknown"
 
 
 class N2VCConnector(abc.ABC, Loggable):
@@ -51,35 +52,39 @@
     """
 
     """
-    ##################################################################################################
-    ########################################## P U B L I C ###########################################
-    ##################################################################################################
+    ####################################################################################
+    ################################### P U B L I C ####################################
+    ####################################################################################
     """
 
     def __init__(
-            self,
-            db: object,
-            fs: object,
-            log: object,
-            loop: object,
-            url: str,
-            username: str,
-            vca_config: dict,
-            on_update_db=None
+        self,
+        db: object,
+        fs: object,
+        log: object,
+        loop: object,
+        url: str,
+        username: str,
+        vca_config: dict,
+        on_update_db=None,
     ):
         """Initialize N2VC abstract connector. It defines de API for VCA connectors
 
         :param object db: Mongo object managing the MongoDB (repo common DbBase)
-        :param object fs: FileSystem object managing the package artifacts (repo common FsBase)
+        :param object fs: FileSystem object managing the package artifacts (repo common
+            FsBase)
         :param object log: the logging object to log to
         :param object loop: the loop to use for asyncio (default current thread loop)
-        :param str url: a string that how to connect to the VCA (if needed, IP and port can be obtained from there)
+        :param str url: a string that how to connect to the VCA (if needed, IP and port
+            can be obtained from there)
         :param str username: the username to authenticate with VCA
-        :param dict vca_config: Additional parameters for the specific VCA. For example, for juju it will contain:
+        :param dict vca_config: Additional parameters for the specific VCA. For example,
+            for juju it will contain:
             secret: The password to authenticate with
             public_key: The contents of the juju public SSH key
             ca_cert str: The CA certificate used to authenticate
-        :param on_update_db: callback called when n2vc connector updates database. Received arguments:
+        :param on_update_db: callback called when n2vc connector updates database.
+            Received arguments:
             table: e.g. "nsrs"
             filter: e.g. {_id: <nsd-id> }
             path: e.g. "_admin.deployed.VCA.3."
@@ -87,17 +92,26 @@
         """
 
         # parent class
-        Loggable.__init__(self, log=log, log_to_console=True, prefix='\nN2VC')
+        Loggable.__init__(self, log=log, log_to_console=True, prefix="\nN2VC")
 
         # check arguments
         if db is None:
-            raise N2VCBadArgumentsException('Argument db is mandatory', ['db'])
+            raise N2VCBadArgumentsException("Argument db is mandatory", ["db"])
         if fs is None:
-            raise N2VCBadArgumentsException('Argument fs is mandatory', ['fs'])
+            raise N2VCBadArgumentsException("Argument fs is mandatory", ["fs"])
 
-        self.log.info('url={}, username={}, vca_config={}'.format(
-            url, username, {k: v for k, v in vca_config.items() if k not in ("host", "port", "user", "secret",
-                                                                             "public_key", "ca_cert")}))
+        self.log.info(
+            "url={}, username={}, vca_config={}".format(
+                url,
+                username,
+                {
+                    k: v
+                    for k, v in vca_config.items()
+                    if k
+                    not in ("host", "port", "user", "secret", "public_key", "ca_cert")
+                },
+            )
+        )
 
         # store arguments into self
         self.db = db
@@ -125,21 +139,19 @@
     def get_public_key(self) -> str:
         """Get the VCA ssh-public-key
 
-        Returns the SSH public key from local mahine, to be injected into virtual machines to
-        be managed by the VCA.
+        Returns the SSH public key from local mahine, to be injected into virtual
+        machines to be managed by the VCA.
         First run, a ssh keypair will be created.
         The public key is injected into a VM so that we can provision the
-        machine with Juju, after which Juju will communicate with the VM 
+        machine with Juju, after which Juju will communicate with the VM
         directly via the juju agent.
         """
 
-        public_key = ''
-
         # Find the path where we expect our key lives (~/.ssh)
-        homedir = os.environ.get('HOME')
+        homedir = os.environ.get("HOME")
         if not homedir:
-            self.warning('No HOME environment variable, using /tmp')
-            homedir = '/tmp'
+            self.warning("No HOME environment variable, using /tmp")
+            homedir = "/tmp"
         sshdir = "{}/.ssh".format(homedir)
         if not os.path.exists(sshdir):
             os.mkdir(sshdir)
@@ -150,9 +162,7 @@
         # If we don't have a key generated, then we have to generate it using ssh-keygen
         if not os.path.exists(self.private_key_path):
             cmd = "ssh-keygen -t {} -b {} -N '' -f {}".format(
-                "rsa",
-                "4096",
-                self.private_key_path
+                "rsa", "4096", self.private_key_path
             )
             # run command with arguments
             subprocess.check_output(shlex.split(cmd))
@@ -170,20 +180,24 @@
         db_dict: dict,
         reuse_ee_id: str = None,
         progress_timeout: float = None,
-        total_timeout: float = None
+        total_timeout: float = None,
     ) -> (str, dict):
-        """Create an Execution Environment. Returns when it is created or raises an exception on failing
+        """Create an Execution Environment. Returns when it is created or raises an
+        exception on failing
 
         :param str namespace: Contains a dot separate string.
                     LCM will use: [<nsi-id>].<ns-id>.<vnf-id>.<vdu-id>[-<count>]
         :param dict db_dict: where to write to database when the status changes.
             It contains a dictionary with {collection: str, filter: {},  path: str},
-                e.g. {collection: "nsrs", filter: {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
-        :param str reuse_ee_id: ee id from an older execution. It allows us to reuse an older environment
+                e.g. {collection: "nsrs", filter: {_id: <nsd-id>, path:
+                "_admin.deployed.VCA.3"}
+        :param str reuse_ee_id: ee id from an older execution. It allows us to reuse an
+            older environment
         :param float progress_timeout:
         :param float total_timeout:
         :returns str, dict: id of the new execution environment and credentials for it
-                    (credentials can contains hostname, username, etc depending on underlying cloud)
+                    (credentials can contains hostname, username, etc depending on
+                    underlying cloud)
         """
 
     @abc.abstractmethod
@@ -193,17 +207,20 @@
         credentials: dict,
         db_dict: dict,
         progress_timeout: float = None,
-        total_timeout: float = None
+        total_timeout: float = None,
     ) -> str:
         """
         Register an existing execution environment at the VCA
 
         :param str namespace: same as create_execution_environment method
-        :param dict credentials: credentials to access the existing execution environment
-                    (it can contains hostname, username, path to private key, etc depending on underlying cloud)
+        :param dict credentials: credentials to access the existing execution
+            environment
+            (it can contains hostname, username, path to private key, etc depending on
+            underlying cloud)
         :param dict db_dict: where to write to database when the status changes.
             It contains a dictionary with {collection: str, filter: {},  path: str},
-                e.g. {collection: "nsrs", filter: {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
+                e.g. {collection: "nsrs", filter:
+                    {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
         :param float progress_timeout:
         :param float total_timeout:
         :returns str: id of the execution environment
@@ -216,19 +233,22 @@
         artifact_path: str,
         db_dict: dict,
         progress_timeout: float = None,
-        total_timeout: float = None
+        total_timeout: float = None,
     ):
         """
         Install the software inside the execution environment identified by ee_id
 
-        :param str ee_id: the id of the execution environment returned by create_execution_environment
-                        or register_execution_environment
-        :param str artifact_path: where to locate the artifacts (parent folder) using the self.fs
-            the final artifact path will be a combination of this artifact_path and additional string from
-            the config_dict (e.g. charm name)
+        :param str ee_id: the id of the execution environment returned by
+            create_execution_environment or register_execution_environment
+        :param str artifact_path: where to locate the artifacts (parent folder) using
+            the self.fs
+            the final artifact path will be a combination of this artifact_path and
+            additional string from the config_dict (e.g. charm name)
         :param dict db_dict: where to write into database when the status changes.
-                        It contains a dict with {collection: <str>, filter: {},  path: <str>},
-                            e.g. {collection: "nsrs", filter: {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
+                        It contains a dict with
+                            {collection: <str>, filter: {},  path: <str>},
+                            e.g. {collection: "nsrs", filter:
+                                {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
         :param float progress_timeout:
         :param float total_timeout:
         """
@@ -239,34 +259,34 @@
         ee_id: str,
         db_dict: dict,
         progress_timeout: float = None,
-        total_timeout: float = None
+        total_timeout: float = None,
     ) -> str:
         """
-        Generate a priv/pub key pair in the execution environment and return the public key
+        Generate a priv/pub key pair in the execution environment and return the public
+        key
 
-        :param str ee_id: the id of the execution environment returned by create_execution_environment
-                        or register_execution_environment
+        :param str ee_id: the id of the execution environment returned by
+            create_execution_environment or register_execution_environment
         :param dict db_dict: where to write into database when the status changes.
-                        It contains a dict with {collection: <str>, filter: {},  path: <str>},
-                            e.g. {collection: "nsrs", filter: {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
+                        It contains a dict with
+                            {collection: <str>, filter: {},  path: <str>},
+                            e.g. {collection: "nsrs", filter:
+                                {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
         :param float progress_timeout:
         :param float total_timeout:
         :returns: public key of the execution environment
-                    For the case of juju proxy charm ssh-layered, it is the one returned by 'get-ssh-public-key'
-                    primitive.
+                    For the case of juju proxy charm ssh-layered, it is the one
+                    returned by 'get-ssh-public-key' primitive.
                     It raises a N2VC exception if fails
         """
 
     @abc.abstractmethod
     async def add_relation(
-        self,
-        ee_id_1: str,
-        ee_id_2: str,
-        endpoint_1: str,
-        endpoint_2: str
+        self, ee_id_1: str, ee_id_2: str, endpoint_1: str, endpoint_2: str
     ):
         """
-        Add a relation between two Execution Environments (using their associated endpoints).
+        Add a relation between two Execution Environments (using their associated
+        endpoints).
 
         :param str ee_id_1: The id of the first execution environment
         :param str ee_id_2: The id of the second execution environment
@@ -276,49 +296,43 @@
 
     # TODO
     @abc.abstractmethod
-    async def remove_relation(
-        self
-    ):
+    async def remove_relation(self):
         """
         """
 
     # TODO
     @abc.abstractmethod
-    async def deregister_execution_environments(
-        self
-    ):
+    async def deregister_execution_environments(self):
         """
         """
 
     @abc.abstractmethod
     async def delete_namespace(
-        self,
-        namespace: str,
-        db_dict: dict = None,
-        total_timeout: float = None
+        self, namespace: str, db_dict: dict = None, total_timeout: float = None
     ):
         """
         Remove a network scenario and its execution environments
         :param namespace: [<nsi-id>].<ns-id>
         :param dict db_dict: where to write into database when the status changes.
-                        It contains a dict with {collection: <str>, filter: {},  path: <str>},
-                            e.g. {collection: "nsrs", filter: {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
+                        It contains a dict with
+                            {collection: <str>, filter: {},  path: <str>},
+                            e.g. {collection: "nsrs", filter:
+                                {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
         :param float total_timeout:
         """
 
     @abc.abstractmethod
     async def delete_execution_environment(
-        self,
-        ee_id: str,
-        db_dict: dict = None,
-        total_timeout: float = None
+        self, ee_id: str, db_dict: dict = None, total_timeout: float = None
     ):
         """
         Delete an execution environment
         :param str ee_id: id of the execution environment to delete
         :param dict db_dict: where to write into database when the status changes.
-                        It contains a dict with {collection: <str>, filter: {},  path: <str>},
-                            e.g. {collection: "nsrs", filter: {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
+                        It contains a dict with
+                            {collection: <str>, filter: {},  path: <str>},
+                            e.g. {collection: "nsrs", filter:
+                                {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
         :param float total_timeout:
         """
 
@@ -330,18 +344,22 @@
         params_dict: dict,
         db_dict: dict = None,
         progress_timeout: float = None,
-        total_timeout: float = None
+        total_timeout: float = None,
     ) -> str:
         """
         Execute a primitive in the execution environment
 
-        :param str ee_id: the one returned by create_execution_environment or register_execution_environment
-        :param str primitive_name: must be one defined in the software. There is one called 'config',
-            where, for the proxy case, the 'credentials' of VM are provided
+        :param str ee_id: the one returned by create_execution_environment or
+            register_execution_environment
+        :param str primitive_name: must be one defined in the software. There is one
+            called 'config', where, for the proxy case, the 'credentials' of VM are
+            provided
         :param dict params_dict: parameters of the action
         :param dict db_dict: where to write into database when the status changes.
-                        It contains a dict with {collection: <str>, filter: {},  path: <str>},
-                            e.g. {collection: "nsrs", filter: {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
+                        It contains a dict with
+                            {collection: <str>, filter: {},  path: <str>},
+                            e.g. {collection: "nsrs", filter:
+                                {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
         :param float progress_timeout:
         :param float total_timeout:
         :returns str: primitive result, if ok. It raises exceptions in case of fail
@@ -353,9 +371,9 @@
         """
 
     """
-    ##################################################################################################
-    ########################################## P R I V A T E #########################################
-    ##################################################################################################
+    ####################################################################################
+    ################################### P R I V A T E ##################################
+    ####################################################################################
     """
 
     def _get_namespace_components(self, namespace: str) -> (str, str, str, str, str):
@@ -368,10 +386,12 @@
 
         # check parameters
         if namespace is None or len(namespace) == 0:
-            raise N2VCBadArgumentsException('Argument namespace is mandatory', ['namespace'])
+            raise N2VCBadArgumentsException(
+                "Argument namespace is mandatory", ["namespace"]
+            )
 
         # split namespace components
-        parts = namespace.split('.')
+        parts = namespace.split(".")
         nsi_id = None
         ns_id = None
         vnf_id = None
@@ -385,7 +405,7 @@
             vnf_id = parts[2]
         if len(parts) > 3 and len(parts[3]) > 0:
             vdu_id = parts[3]
-            vdu_parts = parts[3].split('-')
+            vdu_parts = parts[3].split("-")
             if len(vdu_parts) > 1:
                 vdu_id = vdu_parts[0]
                 vdu_count = vdu_parts[1]
@@ -393,79 +413,85 @@
         return nsi_id, ns_id, vnf_id, vdu_id, vdu_count
 
     async def write_app_status_to_db(
-            self,
-            db_dict: dict,
-            status: N2VCDeploymentStatus,
-            detailed_status: str,
-            vca_status: str,
-            entity_type: str
+        self,
+        db_dict: dict,
+        status: N2VCDeploymentStatus,
+        detailed_status: str,
+        vca_status: str,
+        entity_type: str,
     ):
         if not db_dict:
-            self.log.debug('No db_dict => No database write')
+            self.log.debug("No db_dict => No database write")
             return
 
-        # self.log.debug('status={} / detailed-status={} / VCA-status={} / entity_type={}'
-        #            .format(str(status.value), detailed_status, vca_status, entity_type))
+        # self.log.debug('status={} / detailed-status={} / VCA-status={}/entity_type={}'
+        #          .format(str(status.value), detailed_status, vca_status, entity_type))
 
         try:
 
-            the_table = db_dict['collection']
-            the_filter = db_dict['filter']
-            the_path = db_dict['path']
-            if not the_path[-1] == '.':
-                the_path = the_path + '.'
+            the_table = db_dict["collection"]
+            the_filter = db_dict["filter"]
+            the_path = db_dict["path"]
+            if not the_path[-1] == ".":
+                the_path = the_path + "."
             update_dict = {
-                the_path + 'status': str(status.value),
-                the_path + 'detailed-status': detailed_status,
-                the_path + 'VCA-status': vca_status,
-                the_path + 'entity-type': entity_type,
-                the_path + 'status-time': str(time.time()),
+                the_path + "status": str(status.value),
+                the_path + "detailed-status": detailed_status,
+                the_path + "VCA-status": vca_status,
+                the_path + "entity-type": entity_type,
+                the_path + "status-time": str(time.time()),
             }
 
             self.db.set_one(
                 table=the_table,
                 q_filter=the_filter,
                 update_dict=update_dict,
-                fail_on_empty=True
+                fail_on_empty=True,
             )
 
             # database callback
             if self.on_update_db:
                 if asyncio.iscoroutinefunction(self.on_update_db):
-                    await self.on_update_db(the_table, the_filter, the_path, update_dict)
+                    await self.on_update_db(
+                        the_table, the_filter, the_path, update_dict
+                    )
                 else:
                     self.on_update_db(the_table, the_filter, the_path, update_dict)
 
         except DbException as e:
             if e.http_code == HTTPStatus.NOT_FOUND:
-                self.log.error('NOT_FOUND error: Exception writing status to database: {}'.format(e))
+                self.log.error(
+                    "NOT_FOUND error: Exception writing status to database: {}".format(
+                        e
+                    )
+                )
             else:
-                self.log.info('Exception writing status to database: {}'.format(e))
+                self.log.info("Exception writing status to database: {}".format(e))
 
 
-def juju_status_2_osm_status(type: str, status: str) -> N2VCDeploymentStatus:
-    if type == 'application' or type == 'unit':
-        if status in ['waiting', 'maintenance']:
+def juju_status_2_osm_status(statustype: str, status: str) -> N2VCDeploymentStatus:
+    if statustype == "application" or statustype == "unit":
+        if status in ["waiting", "maintenance"]:
             return N2VCDeploymentStatus.RUNNING
-        if status in ['error']:
-                return N2VCDeploymentStatus.FAILED
-        elif status in ['active']:
+        if status in ["error"]:
+            return N2VCDeploymentStatus.FAILED
+        elif status in ["active"]:
             return N2VCDeploymentStatus.COMPLETED
-        elif status in ['blocked']:
+        elif status in ["blocked"]:
             return N2VCDeploymentStatus.RUNNING
         else:
             return N2VCDeploymentStatus.UNKNOWN
-    elif type == 'action':
-        if status in ['running']:
+    elif statustype == "action":
+        if status in ["running"]:
             return N2VCDeploymentStatus.RUNNING
-        elif status in ['completed']:
+        elif status in ["completed"]:
             return N2VCDeploymentStatus.COMPLETED
         else:
             return N2VCDeploymentStatus.UNKNOWN
-    elif type == 'machine':
-        if status in ['pending']:
+    elif statustype == "machine":
+        if status in ["pending"]:
             return N2VCDeploymentStatus.PENDING
-        elif status in ['started']:
+        elif status in ["started"]:
             return N2VCDeploymentStatus.COMPLETED
         else:
             return N2VCDeploymentStatus.UNKNOWN
@@ -479,12 +505,12 @@
     # split lines
     lines = dump_text.splitlines()
     # remove !!python/object tags
-    yaml_text = ''
+    yaml_text = ""
     for line in lines:
-        index = line.find('!!python/object')
+        index = line.find("!!python/object")
         if index >= 0:
             line = line[:index]
-        yaml_text += line + '\n'
+        yaml_text += line + "\n"
     return yaml_text