Initial commit of ovsdb-manager interface

.gitignore

@@ -0,0 +1,2 @@
+bin
+.settings

copyright

@@ -0,0 +1,9 @@
+Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0
+
+Files: *
+Copyright: 2015, Canonical Ltd.
+License: GPL-3
+
+License: GPL-3
+ On Debian GNU/Linux system you can find the complete text of the
+ GPL-3 license in '/usr/share/common-licenses/GPL-3'

interface.yaml

@@ -0,0 +1,3 @@
+name: ovsdb-manager
+summary: Interface for relating to the OVSDB manager aspect of OpenDayLight SDN
+maintainer: James Page <james.page@ubuntu.com>

requires.py

@@ -0,0 +1,38 @@
+from charmhelpers.core.reactive import hook
+from charmhelpers.core.reactive import RelationBase
+from charmhelpers.core.reactive import scopes
+
+
+class OVSDBManagerRequires(RelationBase):
+    scope = scopes.GLOBAL
+    auto_accessors = ['protocol', 'private-address', 'host', 'port']
+
+    @hook('{requires:ovsdb-manager}-relation-{joined,changed,departed}')
+    def changed(self):
+        self.set_state('{relation_name}.connected')
+        if self.connection_string():
+            self.set_state('{relation_name}.access.available')
+        else:
+            self.remove_state('{relation_name}.access.available')
+
+    @hook('{requires:ovsdb-manager}-relation-broken')
+    def broken(self):
+        self.remove_state('{relation_name}.connected')
+        self.remove_state('{relation_name}.access.available')
+
+    def connection_string(self):
+        """Open vSwitch connection string
+
+        Returns the connection string to use for Open vSwitch or None
+        if the remote ODL controller has not presented this data
+        yet.
+        """
+        data = {
+            'host': self.host() or self.private_address(),
+            'port': self.port() or '6640',
+            'protocol': self.protocol(),
+        }
+        if all(data.values()):
+            return "{protocol}:{host}:{port}".format(**data)
+        else:
+            return None