Added a method for parsing host:port pairs.

The method works correctly with ipv6.
An alternative way would be to use urlparse, but urlparse
only works correctly starting with Python 2.7, so to be
compatible, we have to reimplement this part.

The method will be used for parsing Glance API server
addresses, RabbitMQ addresses and perhaps other things.

Change-Id: Ie5014891c6abcd80681a370d5dd94cb0406f7f61

1 files changed, 44 insertions, 0 deletions

diff --git a/openstack/common/utils.py b/openstack/common/utils.py
index 74c571d..7df3dbc 100644
--- a/openstack/common/utils.py
+++ b/openstack/common/utils.py
@@ -64,6 +64,50 @@ def bool_from_string(subject):
     return False
 
 
+def parse_host_port(address, default_port=None):
+    """
+    Interpret a string as a host:port pair.
+    An IPv6 address MUST be escaped if accompanied by a port,
+    because otherwise ambiguity ensues: 2001:db8:85a3::8a2e:370:7334
+    means both [2001:db8:85a3::8a2e:370:7334] and
+    [2001:db8:85a3::8a2e:370]:7334.
+
+    >>> parse_host_port('server01:80')
+    ('server01', 80)
+    >>> parse_host_port('server01')
+    ('server01', None)
+    >>> parse_host_port('server01', default_port=1234)
+    ('server01', 1234)
+    >>> parse_host_port('[::1]:80')
+    ('::1', 80)
+    >>> parse_host_port('[::1]')
+    ('::1', None)
+    >>> parse_host_port('[::1]', default_port=1234)
+    ('::1', 1234)
+    >>> parse_host_port('2001:db8:85a3::8a2e:370:7334', default_port=1234)
+    ('2001:db8:85a3::8a2e:370:7334', 1234)
+
+    """
+    if address[0] == '[':
+        # Escaped ipv6
+        _host, _port = address[1:].split(']')
+        host = _host
+        if ':' in _port:
+            port = _port.split(':')[1]
+        else:
+            port = default_port
+    else:
+        if address.count(':') == 1:
+            host, port = address.split(':')
+        else:
+            # 0 means ipv4, >1 means ipv6.
+            # We prohibit unescaped ipv6 addresses with port.
+            host = address
+            port = default_port
+
+    return (host, None if port is None else int(port))
+
+
 def execute(*cmd, **kwargs):
     """
     Helper method to execute command with optional retry.