Relation support for multi-charm VNFs
[osm/N2VC.git] / n2vc / vnf.py
index df3ec00..31e4877 100644 (file)
@@ -3,7 +3,9 @@ import logging
 import os
 import os.path
 import re
+import shlex
 import ssl
+import subprocess
 import sys
 # import time
 
@@ -17,7 +19,7 @@ if path not in sys.path:
 
 from juju.controller import Controller
 from juju.model import ModelObserver
-
+from juju.errors import JujuAPIError
 
 # We might need this to connect to the websocket securely, but test and verify.
 try:
@@ -87,20 +89,14 @@ class VCAMonitor(ModelObserver):
                     self.applications[application_name]['callback_args']
 
                 if old and new:
-                    old_status = old.workload_status
-                    new_status = new.workload_status
-
-                    if old_status == new_status:
-                        """The workload status may fluctuate around certain
-                        events, so wait until the status has stabilized before
-                        triggering the callback."""
-                        if callback:
-                            callback(
-                                self.ns_name,
-                                delta.data['application'],
-                                new_status,
-                                new.workload_status_message,
-                                *callback_args)
+                    # Fire off a callback with the application state
+                    if callback:
+                        callback(
+                            self.ns_name,
+                            delta.data['application'],
+                            new.workload_status,
+                            new.workload_status_message,
+                            *callback_args)
 
                 if old and not new:
                     # This is a charm being removed
@@ -173,6 +169,12 @@ class N2VC:
         self.connecting = False
         self.authenticated = False
 
+        # For debugging
+        self.refcount = {
+            'controller': 0,
+            'model': 0,
+        }
+
         self.models = {}
         self.default_model = None
 
@@ -252,6 +254,100 @@ class N2VC:
 
         return self.default_model
 
+    async def Relate(self, ns_name, vnfd):
+        """Create a relation between the charm-enabled VDUs in a VNF.
+
+        The Relation mapping has two parts: the id of the vdu owning the endpoint, and the name of the endpoint.
+
+        vdu:
+            ...
+            relation:
+            -   provides: dataVM:db
+                requires: mgmtVM:app
+
+        This tells N2VC that the charm referred to by the dataVM vdu offers a relation named 'db', and the mgmtVM vdu has an 'app' endpoint that should be connected to a database.
+
+        :param str ns_name: The name of the network service.
+        :param dict vnfd: The parsed yaml VNF descriptor.
+        """
+
+        # Currently, the call to Relate() is made automatically after the
+        # deployment of each charm; if the relation depends on a charm that
+        # hasn't been deployed yet, the call will fail silently. This will
+        # prevent an API breakage, with the intent of making this an explicitly
+        # required call in a more object-oriented refactor of the N2VC API.
+
+        configs = []
+        vnf_config = vnfd.get("vnf-configuration")
+        if vnf_config:
+            juju = vnf_config['juju']
+            if juju:
+                configs.append(vnf_config)
+
+        for vdu in vnfd['vdu']:
+            vdu_config = vdu.get('vdu-configuration')
+            if vdu_config:
+                juju = vdu_config['juju']
+                if juju:
+                    configs.append(vdu_config)
+
+        def _get_application_name(name):
+            """Get the application name that's mapped to a vnf/vdu."""
+            vnf_member_index = 0
+            vnf_name = vnfd['name']
+
+            for vdu in vnfd.get('vdu'):
+                # Compare the named portion of the relation to the vdu's id
+                if vdu['id'] == name:
+                    application_name = self.FormatApplicationName(
+                        ns_name,
+                        vnf_name,
+                        str(vnf_member_index),
+                    )
+                    return application_name
+                else:
+                    vnf_member_index += 1
+
+            return None
+
+        # Loop through relations
+        for cfg in configs:
+            if 'juju' in cfg:
+                if 'relation' in juju:
+                    for rel in juju['relation']:
+                        try:
+
+                            # get the application name for the provides
+                            (name, endpoint) = rel['provides'].split(':')
+                            application_name = _get_application_name(name)
+
+                            provides = "{}:{}".format(
+                                application_name,
+                                endpoint
+                            )
+
+                            # get the application name for thr requires
+                            (name, endpoint) = rel['requires'].split(':')
+                            application_name = _get_application_name(name)
+
+                            requires = "{}:{}".format(
+                                application_name,
+                                endpoint
+                            )
+                            self.log.debug("Relation: {} <-> {}".format(
+                                provides,
+                                requires
+                            ))
+                            await self.add_relation(
+                                ns_name,
+                                provides,
+                                requires,
+                            )
+                        except Exception as e:
+                            self.log.debug("Exception: {}".format(e))
+
+        return
+
     async def DeployCharms(self, model_name, application_name, vnfd,
                            charm_path, params={}, machine_spec={},
                            callback=None, *callback_args):
@@ -333,15 +429,14 @@ class N2VC:
         ########################################################
         to = ""
         if machine_spec.keys():
-            # TODO: This needs to be tested.
-            # if all(k in machine_spec for k in ['hostname', 'username']):
-            #     # Enlist the existing machine in Juju
-            #     machine = await self.model.add_machine(spec='ssh:%@%'.format(
-            #         specs['host'],
-            #         specs['user'],
-            #     ))
-            #     to = machine.id
-            pass
+            if all(k in machine_spec for k in ['host', 'user']):
+                # Enlist an existing machine as a Juju unit
+                machine = await model.add_machine(spec='ssh:{}@{}:{}'.format(
+                    machine_spec['user'],
+                    machine_spec['host'],
+                    self.GetPrivateKeyPath(),
+                ))
+                to = machine.id
 
         #######################################
         # Get the initial charm configuration #
@@ -351,9 +446,6 @@ class N2VC:
         if 'rw_mgmt_ip' in params:
             rw_mgmt_ip = params['rw_mgmt_ip']
 
-        # initial_config = {}
-        # self.log.debug(type(params))
-        # self.log.debug("Params: {}".format(params))
         if 'initial-config-primitive' not in params:
             params['initial-config-primitive'] = {}
 
@@ -382,10 +474,14 @@ class N2VC:
             series='xenial',
             # Apply the initial 'config' primitive during deployment
             config=initial_config,
-            # TBD: Where to deploy the charm to.
-            to=None,
+            # Where to deploy the charm to.
+            to=to,
         )
 
+        # Map the vdu id<->app name,
+        #
+        await self.Relate(model_name, vnfd)
+
         # #######################################
         # # Execute initial config primitive(s) #
         # #######################################
@@ -487,6 +583,77 @@ class N2VC:
 
         return results
 
+    # async def ProvisionMachine(self, model_name, hostname, username):
+    #     """Provision machine for usage with Juju.
+    #
+    #     Provisions a previously instantiated machine for use with Juju.
+    #     """
+    #     try:
+    #         if not self.authenticated:
+    #             await self.login()
+    #
+    #         # FIXME: This is hard-coded until model-per-ns is added
+    #         model_name = 'default'
+    #
+    #         model = await self.get_model(model_name)
+    #         model.add_machine(spec={})
+    #
+    #         machine = await model.add_machine(spec='ssh:{}@{}:{}'.format(
+    #             "ubuntu",
+    #             host['address'],
+    #             private_key_path,
+    #         ))
+    #         return machine.id
+    #
+    #     except Exception as e:
+    #         self.log.debug(
+    #             "Caught exception while getting primitive status: {}".format(e)
+    #         )
+    #         raise N2VCPrimitiveExecutionFailed(e)
+
+    def GetPrivateKeyPath(self):
+        homedir = os.environ['HOME']
+        sshdir = "{}/.ssh".format(homedir)
+        private_key_path = "{}/id_n2vc_rsa".format(sshdir)
+        return private_key_path
+
+    async def GetPublicKey(self):
+        """Get the N2VC SSH public key.abs
+
+        Returns the SSH public key, to be injected into virtual machines to
+        be managed by the VCA.
+
+        The first time this is 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 directly via the
+        juju agent.
+        """
+        public_key = ""
+
+        # Find the path to where we expect our key to live.
+        homedir = os.environ['HOME']
+        sshdir = "{}/.ssh".format(homedir)
+        if not os.path.exists(sshdir):
+            os.mkdir(sshdir)
+
+        private_key_path = "{}/id_n2vc_rsa".format(sshdir)
+        public_key_path = "{}.pub".format(private_key_path)
+
+        # If we don't have a key generated, generate it.
+        if not os.path.exists(private_key_path):
+            cmd = "ssh-keygen -t {} -b {} -N '' -f {}".format(
+                "rsa",
+                "4096",
+                private_key_path
+            )
+            subprocess.check_output(shlex.split(cmd))
+
+        # Read the public key
+        with open(public_key_path, "r") as f:
+            public_key = f.readline()
+
+        return public_key
+
     async def ExecuteInitialPrimitives(self, model_name, application_name,
                                        params, callback=None, *callback_args):
         """Execute multiple primitives.
@@ -650,24 +817,39 @@ class N2VC:
 
         return metrics
 
+    async def HasApplication(self, model_name, application_name):
+        model = await self.get_model(model_name)
+        app = await self.get_application(model, application_name)
+        if app:
+            return True
+        return False
+
     # Non-public methods
-    async def add_relation(self, a, b, via=None):
+    async def add_relation(self, model_name, relation1, relation2):
         """
         Add a relation between two application endpoints.
 
-        :param a An application endpoint
-        :param b An application endpoint
-        :param via The egress subnet(s) for outbound traffic, e.g.,
-            (192.168.0.0/16,10.0.0.0/8)
+        :param str model_name Name of the network service.
+        :param str relation1 '<application>[:<relation_name>]'
+        :param str relation12 '<application>[:<relation_name>]'
         """
+
         if not self.authenticated:
             await self.login()
 
-        m = await self.get_model()
+        m = await self.get_model(model_name)
         try:
-            m.add_relation(a, b, via)
-        finally:
-            await m.disconnect()
+            await m.add_relation(relation1, relation2)
+        except JujuAPIError as e:
+            # If one of the applications in the relationship doesn't exist,
+            # or the relation has already been added, let the operation fail
+            # silently.
+            if 'not found' in e.message:
+                return
+            if 'already exists' in e.message:
+                return
+
+            raise e
 
     # async def apply_config(self, config, application):
     #     """Apply a configuration to the application."""
@@ -811,6 +993,7 @@ class N2VC:
             self.models[model_name] = await self.controller.get_model(
                 model_name,
             )
+            self.refcount['model'] += 1
 
             # Create an observer for this model
             self.monitors[model_name] = VCAMonitor(model_name)
@@ -846,6 +1029,7 @@ class N2VC:
                 password=self.secret,
                 cacert=cacert,
             )
+            self.refcount['controller'] += 1
         else:
             # current_controller no longer exists
             # self.log.debug("Connecting to current controller...")
@@ -860,8 +1044,6 @@ class N2VC:
         self.authenticated = True
         self.log.debug("JujuApi: Logged into controller")
 
-        # self.default_model = await self.controller.get_model("default")
-
     async def logout(self):
         """Logout of the Juju controller."""
         if not self.authenticated:
@@ -873,20 +1055,26 @@ class N2VC:
                     self.default_model
                 ))
                 await self.default_model.disconnect()
+                self.refcount['model'] -= 1
                 self.default_model = None
 
             for model in self.models:
                 await self.models[model].disconnect()
-                model = None
+                self.refcount['model'] -= 1
+                self.models[model] = None
 
             if self.controller:
                 self.log.debug("Disconnecting controller {}".format(
                     self.controller
                 ))
                 await self.controller.disconnect()
+                self.refcount['controller'] -= 1
                 self.controller = None
 
             self.authenticated = False
+
+            self.log.debug(self.refcount)
+
         except Exception as e:
             self.log.fatal(
                 "Fatal error logging out of Juju Controller: {}".format(e)