Fixing HostName and adding support for HostAddress

When config options in different projects use IPOpt as the opt's
type, it restricts operators to only IP addresses.
When the opt is set to HostnameOpt type, currently even an
incomplete or invalid IP passes as a valid hostname. Also, currently
HostnameOpt does not make sure that there is a presense of at least one
non-numeric character in the provided host name.

According to RFC 1123, (https://tools.ietf.org/html/rfc1123),
a valid host name can never have the dotted-decimal form #.#.#.#,
since at least the highest-level component label will be alphabetic.

This patch fixes the existing Hostname Opt to abide by the stated RFC
and also adds a new opt type that would enable operators to provide
either a hostname or an IP and at the same time perform checks on
both IPOpt type and HostnameOpt type, by setting opt type to
"HostAddressOpt" type. This would ensure that an invalid IP does
not pass as a valid hostname and at the same time retains the rules
required to be followed for the validation of an acceptable hostname.

Change-Id: I77bdb64b7e6e56ce761d76696bc4448a9bd325eb
Closes-Bug: #1619044
Closes-Bug: #1615028

7 files changed, 129 insertions, 5 deletions

diff --git a/doc/source/opts.rst b/doc/source/opts.rst
index e82ecff..ccdf9a3 100644
--- a/doc/source/opts.rst
+++ b/doc/source/opts.rst
@@ -16,6 +16,7 @@ Option Definitions
 .. autoclass:: IPOpt
 .. autoclass:: PortOpt
 .. autoclass:: HostnameOpt
+.. autoclass:: HostAddressOpt
 .. autoclass:: URIOpt
 .. autoclass:: DeprecatedOpt
 .. autoclass:: SubCommandOpt
diff --git a/oslo_config/cfg.py b/oslo_config/cfg.py
index bc57200..bb94b33 100644
--- a/oslo_config/cfg.py
+++ b/oslo_config/cfg.py
@@ -59,6 +59,7 @@ Type                                  Option
 :class:`oslo_config.types.Dict`       :class:`oslo_config.cfg.DictOpt`
 :class:`oslo_config.types.IPAddress`  :class:`oslo_config.cfg.IPOpt`
 :class:`oslo_config.types.Hostname`   :class:`oslo_config.cfg.HostnameOpt`
+:class:`oslo_config.types.HostAddress`:class:`oslo_config.cfg.HostAddressOpt`
 :class:`oslo_config.types.URI`        :class:`oslo_config.cfg.URIOpt`
 ====================================  ======
 
@@ -1318,6 +1319,20 @@ class HostnameOpt(Opt):
                                           **kwargs)
 
 
+class HostAddressOpt(Opt):
+    """Option for either an IP or a hostname.
+
+       Accepts valid hostnames and valid IP addresses.
+
+       .. versionadded:: 3.22
+    """
+
+    def __init__(self, name, version=None, **kwargs):
+        super(HostAddressOpt, self).__init__(name,
+                                             type=types.HostAddress(version),
+                                             **kwargs)
+
+
 class URIOpt(Opt):
 
     """Opt with URI type
diff --git a/oslo_config/generator.py b/oslo_config/generator.py
index 22a9f28..e2025c9 100644
--- a/oslo_config/generator.py
+++ b/oslo_config/generator.py
@@ -80,7 +80,8 @@ def _format_defaults(opt):
         elif opt.default is None:
             default_str = '<None>'
         elif (isinstance(opt, (cfg.StrOpt, cfg.IPOpt,
-                               cfg.HostnameOpt, cfg.URIOpt))):
+                               cfg.HostnameOpt, cfg.HostAddressOpt,
+                               cfg.URIOpt))):
             default_str = opt.default
         elif isinstance(opt, cfg.BoolOpt):
             default_str = str(opt.default).lower()
diff --git a/oslo_config/sphinxext.py b/oslo_config/sphinxext.py
index cd74187..8439c07 100644
--- a/oslo_config/sphinxext.py
+++ b/oslo_config/sphinxext.py
@@ -77,6 +77,7 @@ _TYPE_DESCRIPTIONS = {
     cfg.PortOpt: 'port number',
     cfg.HostnameOpt: 'hostname',
     cfg.URIOpt: 'URI',
+    cfg.HostAddressOpt: 'host address',
     cfg._ConfigFileOpt: 'list of filenames',
     cfg._ConfigDirOpt: 'list of directory names',
 }
diff --git a/oslo_config/tests/test_types.py b/oslo_config/tests/test_types.py
index 8457263..41edf6b 100644
--- a/oslo_config/tests/test_types.py
+++ b/oslo_config/tests/test_types.py
@@ -687,6 +687,32 @@ class IPv6AddressTypeTests(IPAddressTypeTests):
         self.assertInvalid('192.168.0.1')
 
 
+class HostAddressTypeTests(TypeTestHelper, unittest.TestCase):
+    type = types.HostAddress()
+
+    def test_invalid_host_addresses(self):
+        self.assertInvalid('-1')
+        self.assertInvalid('_foo')
+        self.assertInvalid('3.14')
+        self.assertInvalid('10.0')
+        self.assertInvalid('host..name')
+        self.assertInvalid('org.10')
+        self.assertInvalid('0.0.00')
+
+    def test_valid_host_addresses(self):
+        self.assertConvertedValue('foo.bar', 'foo.bar')
+        self.assertConvertedValue('192.168.0.1', '192.168.0.1')
+        self.assertConvertedValue('abcd:ef::1', 'abcd:ef::1')
+        self.assertConvertedValue('home-site-here.org.com',
+                                  'home-site-here.org.com')
+        self.assertConvertedValue('3com.com', '3com.com')
+        self.assertConvertedValue('10.org', '10.org')
+        self.assertConvertedValue('cell1.nova.site1', 'cell1.nova.site1')
+        self.assertConvertedValue('ab-c.com', 'ab-c.com')
+        self.assertConvertedValue('abc.com-org', 'abc.com-org')
+        self.assertConvertedValue('abc.0-0', 'abc.0-0')
+
+
 class HostnameTypeTests(TypeTestHelper, unittest.TestCase):
     type = types.Hostname()
 
@@ -726,6 +752,12 @@ class HostnameTypeTests(TypeTestHelper, unittest.TestCase):
         self.assertInvalid(".host.name.com")
         self.assertInvalid("no spaces")
 
+    def test_invalid_hostnames_with_numeric_characters(self):
+        self.assertInvalid("10.0.0.0")
+        self.assertInvalid("3.14")
+        self.assertInvalid("org.10")
+        self.assertInvalid('0.0.00')
+
     def test_no_start_end_hyphens(self):
         self.assertInvalid("-host.com")
         self.assertInvalid("-hostname.com-")
@@ -739,9 +771,13 @@ class HostnameTypeTests(TypeTestHelper, unittest.TestCase):
         self.assertConvertedEqual('cell1.nova.site1')
         self.assertConvertedEqual('site01001')
         self.assertConvertedEqual('home-site-here.org.com')
-        self.assertConvertedEqual('192.168.0.1')
-        self.assertConvertedEqual('1.1.1')
         self.assertConvertedEqual('localhost')
+        self.assertConvertedEqual('3com.com')
+        self.assertConvertedEqual('10.org')
+        self.assertConvertedEqual('10ab.10ab')
+        self.assertConvertedEqual('ab-c.com')
+        self.assertConvertedEqual('abc.com-org')
+        self.assertConvertedEqual('abc.0-0')
 
     def test_max_segment_size(self):
         self.assertConvertedEqual('host.%s.com' % ('x' * 63))
diff --git a/oslo_config/types.py b/oslo_config/types.py
index 4fd1400..aa33973 100644
--- a/oslo_config/types.py
+++ b/oslo_config/types.py
@@ -703,7 +703,7 @@ class IPAddress(ConfigType):
 
 
 class Hostname(ConfigType):
-    """Hostname type.
+    """Host domain name type.
 
     A hostname refers to a valid DNS or hostname. It must not be longer than
     253 characters, have a segment greater than 63 characters, nor start or
@@ -723,10 +723,14 @@ class Hostname(ConfigType):
         - Contains at least one character and a maximum of 63 characters
         - Consists only of allowed characters: letters (A-Z and a-z),
           digits (0-9), and hyphen (-)
+        - Ensures that the final segment (representing the top level domain
+          name) contains at least one non-numeric character
         - Does not begin or end with a hyphen
         - maximum total length of 253 characters
 
-        For more details , please see: http://tools.ietf.org/html/rfc1035
+        For more details , please see: http://tools.ietf.org/html/rfc1035,
+        https://www.ietf.org/rfc/rfc1912, and
+        https://tools.ietf.org/html/rfc1123
         """
 
         if len(value) == 0:
@@ -737,6 +741,10 @@ class Hostname(ConfigType):
         if value.endswith("."):
             value = value[:-1]
         allowed = re.compile("(?!-)[A-Z0-9-]{1,63}(?<!-)$", re.IGNORECASE)
+        if not re.search('[a-zA-Z-]', value.split(".")[-1]):
+            raise ValueError('%s contains no non-numeric characters in the '
+                             'top-level domain part of the host name and is '
+                             'invalid' % value)
         if any((not allowed.match(x)) for x in value.split(".")):
             raise ValueError("%s is an invalid hostname" % value)
         return value
@@ -751,6 +759,55 @@ class Hostname(ConfigType):
         return value
 
 
+class HostAddress(object):
+    """Host Address type.
+
+    Represents both valid IP addresses and valid host domain names
+    including fully qualified domain names.
+    Performs strict checks for both IP addresses and valid hostnames,
+    matching the opt values to the respective types as per RFC1912.
+
+    :param version: defines which version should be explicitly
+    checked (4 or 6) in case of an IP address
+    :param type_name: Type name to be used in the sample config file.
+
+    """
+
+    def __init__(self, version=None, type_name='host address value'):
+        """Check for valid version in case an IP address is provided
+
+        """
+
+        self.ip_address = IPAddress(version, type_name)
+        self.hostname = Hostname('localhost')
+
+    def __call__(self, value):
+        """Checks if is a valid IP/hostname.
+
+        If not a valid IP, makes sure it is not a mistyped IP before
+        performing checks for it as a hostname.
+
+        """
+
+        try:
+            value = self.ip_address(value)
+        except ValueError:
+            try:
+                value = self.hostname(value)
+            except ValueError:
+                raise ValueError("%s is not a valid host address", value)
+        return value
+
+    def __repr__(self):
+        return 'HostAddress'
+
+    def __eq__(self, other):
+        return self.__class__ == other.__class__
+
+    def _formatter(self, value):
+        return value
+
+
 class URI(ConfigType):
 
     """URI type
diff --git a/releasenotes/notes/add-HostAddressOpt-6e7e2afe7c7863cb.yaml b/releasenotes/notes/add-HostAddressOpt-6e7e2afe7c7863cb.yaml
new file mode 100644
index 0000000..576f464
--- /dev/null
+++ b/releasenotes/notes/add-HostAddressOpt-6e7e2afe7c7863cb.yaml
@@ -0,0 +1,13 @@
+---
+prelude: >
+    Configuration option type of ``HostAddressOpt`` added to accept and
+    validate both IP addresses and hostnames. Please refer to the
+    ``features`` section for more information.
+
+features:
+  - Configuration option type of ``HostAddressOpt`` added to accept both
+    valid IP address (IPv4 and IPv6) values as well as hostnames.
+    The ``HostAddressOpt`` will accept both IPv4 and IPv6 addresses
+    and ensure that strict checks are performed on the IP versions.
+    This option type will also accept and accurately validate hostnames
+    ensuring that no invalid IP passes as a valid hostname.