Relation support for multi-charm VNFs

Adds support for establishing relations between charms

Signed-off-by: Adam Israel <adam.israel@canonical.com>
Change-Id: I9a0b7725013e06635875cd824e219ab6a023efb3

diff --git a/n2vc/vnf.py b/n2vc/vnf.py
index a1fcfe3..31e4877 100644 (file)
--- a/n2vc/vnf.py
+++ b/n2vc/vnf.py
@@ -19,7 +19,7 @@ if path not in sys.path:
 
 from juju.controller import Controller
 from juju.model import ModelObserver
 
 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:
 
 # We might need this to connect to the websocket securely, but test and verify.
 try:


@@ -254,6 +254,100 @@ class N2VC:
 
         return self.default_model
 
 
         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):
     async def DeployCharms(self, model_name, application_name, vnfd,
                            charm_path, params={}, machine_spec={},
                            callback=None, *callback_args):


@@ -384,6 +478,10 @@ class N2VC:
             to=to,
         )
 
             to=to,
         )
 

+        # Map the vdu id<->app name,
+        #
+        await self.Relate(model_name, vnfd)
+

         # #######################################
         # # Execute initial config primitive(s) #
         # #######################################
         # #######################################
         # # Execute initial config primitive(s) #
         # #######################################


@@ -727,23 +825,31 @@ class N2VC:
         return False
 
     # Non-public methods
         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.
 
         """
         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()
 
         if not self.authenticated:
             await self.login()
 

-        m = await self.get_model()
+        m = await self.get_model(model_name)

         try:
         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."""
 
     # async def apply_config(self, config, application):
     #     """Apply a configuration to the application."""

diff --git a/tests/charms/layers/native-ci/layer.yaml b/tests/charms/layers/native-ci/layer.yaml
index edc8839..138d9d3 100644 (file)
--- a/tests/charms/layers/native-ci/layer.yaml
+++ b/tests/charms/layers/native-ci/layer.yaml
@@ -1,4 +1,7 @@
-includes: ['layer:basic']
+includes:
+    - 'layer:basic'
+    - 'interface:mysql'
+    

 options:
     basic:
         use_venv: false
 options:
     basic:
         use_venv: false

diff --git a/tests/charms/layers/native-ci/metadata.yaml b/tests/charms/layers/native-ci/metadata.yaml
index 6acf296..0460e48 100644 (file)
--- a/tests/charms/layers/native-ci/metadata.yaml
+++ b/tests/charms/layers/native-ci/metadata.yaml
@@ -4,3 +4,9 @@ description: A native VNF charm
 maintainer: Adam Israel <adam.israel@canonical.com>
 subordinate: false
 series: ['xenial']
 maintainer: Adam Israel <adam.israel@canonical.com>
 subordinate: false
 series: ['xenial']

+provides:
+    db:
+        interface: mysql
+requires:
+    app:
+        interface: mysql

diff --git a/tests/charms/layers/native-ci/reactive/native-ci.py b/tests/charms/layers/native-ci/reactive/native-ci.py
index 17bf5f4..9e5fe67 100644 (file)
--- a/tests/charms/layers/native-ci/reactive/native-ci.py
+++ b/tests/charms/layers/native-ci/reactive/native-ci.py
@@ -42,3 +42,21 @@ def testint():
         action_set({'output': intval})
     finally:
         clear_flag('actions.testint')
         action_set({'output': intval})
     finally:
         clear_flag('actions.testint')

+
+
+@when('db.joined')
+def provides_db(db):
+    """Simulate providing database credentials."""
+    db.configure(
+        database="mydb",
+        user="myuser",
+        password="mypassword",
+        host="myhost",
+        slave="myslave",
+    )
+
+
+@when('db.available')
+def requires_db(db):
+    """Simulate receiving database credentials."""
+    pass

diff --git a/tests/charms/layers/proxy-ci/metadata.yaml b/tests/charms/layers/proxy-ci/metadata.yaml
index b96abe4..bb00a03 100644 (file)
--- a/tests/charms/layers/proxy-ci/metadata.yaml
+++ b/tests/charms/layers/proxy-ci/metadata.yaml
@@ -10,3 +10,9 @@ tags:
 subordinate: false
 series:
   - xenial
 subordinate: false
 series:
   - xenial

+provides:
+    db:
+        interface: mysql
+requires:
+    app:
+        interface: mysql

diff --git a/tests/charms/layers/proxy-ci/reactive/proxy_ci.py b/tests/charms/layers/proxy-ci/reactive/proxy_ci.py
index 98b7f96..9c0136e 100644 (file)
--- a/tests/charms/layers/proxy-ci/reactive/proxy_ci.py
+++ b/tests/charms/layers/proxy-ci/reactive/proxy_ci.py
@@ -32,3 +32,21 @@ def test():
         action_set({'output': result})
     finally:
         clear_flag('actions.test')
         action_set({'output': result})
     finally:
         clear_flag('actions.test')

+
+
+@when('db.joined')
+def provides_db(db):
+    """Simulate providing database credentials."""
+    db.configure(
+        database="mydb",
+        user="myuser",
+        password="mypassword",
+        host="myhost",
+        slave="myslave",
+    )
+
+
+@when('db.available')
+def requires_db(db):
+    """Simulate receiving database credentials."""
+    pass

diff --git a/tests/integration/test_multivdu_multicharm.py b/tests/integration/test_multivdu_multicharm.py
index e0fb9c7..b879373 100644 (file)
--- a/tests/integration/test_multivdu_multicharm.py
+++ b/tests/integration/test_multivdu_multicharm.py
@@ -144,6 +144,11 @@ class TestCharm(base.TestN2VC):
                     juju:
                         charm: proxy-ci
                         proxy: true
                     juju:
                         charm: proxy-ci
                         proxy: true

+                        # Relation needs to map to the vdu providing or
+                        # requiring, so that we can map to the deployed app.
+                        relation:
+                        -   provides: dataVM:db
+                            requires: mgmtVM:app

                     initial-config-primitive:
                     -   seq: '1'
                         name: test
                     initial-config-primitive:
                     -   seq: '1'
                         name: test