Merge lp:~thedac/charm-helpers/get-relation-ip into lp:charm-helpers

[David Ames]

Add network space aware get_relation_ip

Check network-get --primary-address $RELATION unless overridden

[James Page (james-page)]

review: Approve

=== modified file 'charmhelpers/contrib/network/ip.py'
--- charmhelpers/contrib/network/ip.py	2017-02-16 03:04:17 +0000
+++ charmhelpers/contrib/network/ip.py	2017-03-06 23:53:30 +0000
@@ -20,13 +20,19 @@
 
 from functools import partial
 
-from charmhelpers.core.hookenv import unit_get
 from charmhelpers.fetch import apt_install, apt_update
 from charmhelpers.core.hookenv import (
+    config,
     log,
+    network_get_primary_address,
+    unit_get,
     WARNING,
 )
 
+from charmhelpers.core.host import (
+    lsb_release,
+)
+
 try:
     import netifaces
 except ImportError:
@@ -511,3 +517,40 @@
     cmd = ['nc', '-z', address, str(port)]
     result = subprocess.call(cmd)
     return not(bool(result))
+
+
+def assert_charm_supports_ipv6():
+    """Check whether we are able to support charms ipv6."""
+    if lsb_release()['DISTRIB_CODENAME'].lower() < "trusty":
+        raise Exception("IPv6 is not supported in the charms for Ubuntu "
+                        "versions less than Trusty 14.04")
+
+
+def get_relation_ip(interface, config_override=None):
+    """Return this unit's IP for the given relation.
+
+    Allow for an arbitrary interface to use with network-get to select an IP.
+    Handle all address selection options including configuration parameter
+    override and IPv6.
+
+    Usage: get_relation_ip('amqp', config_override='access-network')
+
+    @param interface: string name of the relation.
+    @param config_override: string name of the config option for network
+           override. Supports legacy network override configuration parameters.
+    @raises Exception if prefer-ipv6 is configured but IPv6 unsupported.
+    @returns IPv6 or IPv4 address
+    """
+
+    fallback = get_host_ip(unit_get('private-address'))
+    if config('prefer-ipv6'):
+        assert_charm_supports_ipv6()
+        return get_ipv6_addr()[0]
+    elif config_override and config(config_override):
+        return get_address_in_network(config(config_override),
+                                      fallback)
+    else:
+        try:
+            return network_get_primary_address(interface)
+        except NotImplementedError:
+            return fallback

=== modified file 'tests/contrib/network/test_ip.py'
--- tests/contrib/network/test_ip.py	2017-02-16 03:04:17 +0000
+++ tests/contrib/network/test_ip.py	2017-03-06 23:53:30 +0000
@@ -749,3 +749,64 @@
         subprocess_call.return_value = 0
         self.assertEqual(net_ip.port_has_listener('ip-address', 70), True)
         subprocess_call.assert_called_with(['nc', '-z', 'ip-address', '70'])
+
+    @patch.object(net_ip, 'config')
+    @patch.object(net_ip, 'network_get_primary_address')
+    @patch.object(net_ip, 'get_address_in_network')
+    @patch.object(net_ip, 'unit_get')
+    @patch.object(net_ip, 'get_ipv6_addr')
+    @patch.object(net_ip, 'assert_charm_supports_ipv6')
+    def test_get_relation_ip(self, assert_charm_supports_ipv6, get_ipv6_addr,
+                             unit_get, get_address_in_network,
+                             network_get_primary_address, config):
+        AMQP_IP = '10.200.1.1'
+        OVERRIDE_AMQP_IP = '10.250.1.1'
+        CLUSTER_IP = '10.100.1.1'
+        OVERRIDE_CLUSTER_IP = '10.150.1.1'
+        IPV6_IP = '2001:DB8::1'
+        DEFAULT_IP = '172.16.1.1'
+        assert_charm_supports_ipv6.return_value = True
+        get_ipv6_addr.return_value = [IPV6_IP]
+        unit_get.return_value = DEFAULT_IP
+        get_address_in_network.return_value = DEFAULT_IP
+        network_get_primary_address.return_value = DEFAULT_IP
+
+        # IPv6
+        _config = {'prefer-ipv6': True,
+                   'cluster-network': '10.100.1.0/24',
+                   'access-network': '10.200.1.0/24'}
+        config.side_effect = lambda key: _config.get(key)
+        self.assertEqual(IPV6_IP, net_ip.get_relation_ip('amqp'))
+
+        # Overrides
+        _config = {'prefer-ipv6': False,
+                   'cluster-network': '10.100.1.0/24',
+                   'access-network': '10.200.1.0/24'}
+        config.side_effect = lambda key: _config.get(key)
+
+        get_address_in_network.return_value = OVERRIDE_AMQP_IP
+        self.assertEqual(
+            OVERRIDE_AMQP_IP,
+            net_ip.get_relation_ip('amqp',
+                                   config_override='access-network'))
+
+        get_address_in_network.return_value = OVERRIDE_CLUSTER_IP
+        self.assertEqual(OVERRIDE_CLUSTER_IP,
+                         net_ip.get_relation_ip(
+                             'cluster',
+                             config_override='cluster-network'))
+
+        # Network-get calls
+        _config = {'prefer-ipv6': False,
+                   'cluster-network': None,
+                   'access-network': None}
+        config.side_effect = lambda key: _config.get(key)
+
+        network_get_primary_address.return_value = AMQP_IP
+        self.assertEqual(AMQP_IP, net_ip.get_relation_ip('amqp'))
+
+        network_get_primary_address.return_value = CLUSTER_IP
+        self.assertEqual(CLUSTER_IP,
+                         net_ip.get_relation_ip(
+                             config_override='cluster-network',
+                             interface='cluster'))