Resolve deprecation warning for rfc3986 uri validation

rfc3986.is_valid_uri is deprecated in 1.1.0. That generates a lot of
warnings: "Please use rfc3986.validators.Validator instead. This
method will be eventually removed.".

This patch updates URI type to use rfc3986.validators.
ValueError exception is preserved.

Change-Id: Ida56dfa17fca0080b74c1a80d5420ebed203431f

lower-constraints.txt

@@ -40,7 +40,7 @@ reno==2.5.0
 requests==2.18.0
 requests_mock==1.5.0
 requestsexceptions==1.2.0
-rfc3986==0.3.1
+rfc3986==1.2.0
 six==1.10.0
 smmap==0.9.0
 snowballstemmer==1.2.1

oslo_config/types.py

@@ -879,20 +879,23 @@ class URI(ConfigType):
         self.schemes = schemes
 
     def __call__(self, value):
-        if not rfc3986.is_valid_uri(value, require_scheme=True,
-                                    require_authority=True):
-            raise ValueError('invalid URI: %r' % value)
+        uri = rfc3986.uri_reference(value)
+        validator = rfc3986.validators.Validator().require_presence_of(
+            'scheme', 'host',
+        ).check_validity_of(
+            'scheme', 'host', 'path',
+        )
+        if self.schemes:
+            validator = validator.allow_schemes(*self.schemes)
+        try:
+            validator.validate(uri)
+        except rfc3986.exceptions.RFC3986Exception as exc:
+            raise ValueError(exc)
 
         if self.max_length is not None and len(value) > self.max_length:
             raise ValueError("Value '%s' exceeds maximum length %d" %
                              (value, self.max_length))
 
-        if self.schemes:
-            scheme = rfc3986.uri_reference(value).scheme
-            if scheme not in self.schemes:
-                raise ValueError("URI scheme '%s' not in %s" %
-                                 (scheme, self.schemes))
-
         # NOTE(dhellmann): self.value is deprecated, and we don't want
         # to trigger a deprecation warning ourselves so we modify
         # self._value directly.

requirements.txt

@@ -7,7 +7,7 @@ netaddr>=0.7.18 # BSD
 six>=1.10.0 # MIT
 stevedore>=1.20.0 # Apache-2.0
 oslo.i18n>=3.15.3 # Apache-2.0
-rfc3986>=0.3.1 # Apache-2.0
+rfc3986>=1.2.0 # Apache-2.0
 PyYAML>=3.12 # MIT
 enum34>=1.0.4;python_version=='2.7' or python_version=='2.6' or python_version=='3.3' # BSD
 requests>=2.18.0 # Apache-2.0