Add python changes for regional_endpoints

Author: alextwoods

packages/smithy-aws-core/src/smithy_aws_core/endpoints/__init__.py

@@ -0,0 +1,2 @@
+#  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#  SPDX-License-Identifier: Apache-2.0

packages/smithy-aws-core/src/smithy_aws_core/endpoints/standard_regional.py

@@ -0,0 +1,59 @@
+#  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#  SPDX-License-Identifier: Apache-2.0
+from dataclasses import dataclass
+from urllib.parse import urlparse
+
+import smithy_core
+from smithy_core import URI
+from smithy_http.aio.interfaces import EndpointResolver
+from smithy_http.endpoints import Endpoint, EndpointResolutionError
+
+
+@dataclass(kw_only=True)
+class RegionalEndpointParameters:
+    """Endpoint parameters for services with standard regional endpoints."""
+
+    sdk_endpoint: str | smithy_core.interfaces.URI | None
+    region: str | None
+
+
+class StandardRegionalEndpointsResolver(EndpointResolver[RegionalEndpointParameters]):
+    """Resolves endpoints for services with standard regional endpoints."""
+
+    def __init__(self, endpoint_prefix: str):
+        self._endpoint_prefix = endpoint_prefix
+
+    async def resolve_endpoint(self, params: RegionalEndpointParameters) -> Endpoint:
+        if params.sdk_endpoint is not None:
+            # If it's not a string, it's already a parsed URI so just pass it along.
+            if not isinstance(params.sdk_endpoint, str):
+                return Endpoint(uri=params.sdk_endpoint)
+
+            parsed = urlparse(params.sdk_endpoint)
+
+            # This will end up getting wrapped in the client.
+            if parsed.hostname is None:
+                raise EndpointResolutionError(
+                    f"Unable to parse hostname from provided URI: {params.sdk_endpoint}"
+                )
+
+            return Endpoint(
+                uri=URI(
+                    host=parsed.hostname,
+                    path=parsed.path,
+                    scheme=parsed.scheme,
+                    query=parsed.query,
+                    port=parsed.port,
+                )
+            )
+
+        if params.region is not None:
+            # TODO: use dns suffix determined from partition metadata
+            dns_suffix = "amazonaws.com"
+            hostname = f"{self._endpoint_prefix}.{params.region}.{dns_suffix}"
+
+            return Endpoint(uri=URI(host=hostname))
+
+        raise EndpointResolutionError(
+            "Unable to resolve endpoint - either endpoint_url or region are required."
+        )

packages/smithy-aws-core/tests/unit/endpoints/test_standard_regional.py

@@ -0,0 +1,73 @@
+#  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#  SPDX-License-Identifier: Apache-2.0
+from smithy_aws_core.endpoints.standard_regional import (
+    StandardRegionalEndpointsResolver,
+    RegionalEndpointParameters,
+)
+
+from smithy_core import URI
+from smithy_http.endpoints import EndpointResolutionError
+
+import pytest
+
+
+async def test_resolve_endpoint_with_valid_sdk_endpoint_string():
+    resolver = StandardRegionalEndpointsResolver(endpoint_prefix="service")
+    params = RegionalEndpointParameters(
+        sdk_endpoint="https://example.com/path?query=123", region=None
+    )
+
+    endpoint = await resolver.resolve_endpoint(params)
+
+    assert endpoint.uri.host == "example.com"
+    assert endpoint.uri.path == "/path"
+    assert endpoint.uri.scheme == "https"
+    assert endpoint.uri.query == "query=123"
+
+
+async def test_resolve_endpoint_with_sdk_endpoint_uri():
+    resolver = StandardRegionalEndpointsResolver(endpoint_prefix="service")
+    parsed_uri = URI(
+        host="example.com", path="/path", scheme="https", query="query=123", port=443
+    )
+    params = RegionalEndpointParameters(sdk_endpoint=parsed_uri, region=None)
+
+    endpoint = await resolver.resolve_endpoint(params)
+
+    assert endpoint.uri == parsed_uri
+
+
+async def test_resolve_endpoint_with_invalid_sdk_endpoint():
+    resolver = StandardRegionalEndpointsResolver(endpoint_prefix="service")
+    params = RegionalEndpointParameters(sdk_endpoint="invalid-uri", region=None)
+
+    with pytest.raises(EndpointResolutionError):
+        await resolver.resolve_endpoint(params)
+
+
+async def test_resolve_endpoint_with_region():
+    resolver = StandardRegionalEndpointsResolver(endpoint_prefix="service")
+    params = RegionalEndpointParameters(sdk_endpoint=None, region="us-west-2")
+
+    endpoint = await resolver.resolve_endpoint(params)
+
+    assert endpoint.uri.host == "service.us-west-2.amazonaws.com"
+
+
+async def test_resolve_endpoint_with_no_sdk_endpoint_or_region():
+    resolver = StandardRegionalEndpointsResolver(endpoint_prefix="service")
+    params = RegionalEndpointParameters(sdk_endpoint=None, region=None)
+
+    with pytest.raises(EndpointResolutionError):
+        await resolver.resolve_endpoint(params)
+
+
+async def test_resolve_endpoint_with_sdk_endpoint_and_region():
+    resolver = StandardRegionalEndpointsResolver(endpoint_prefix="service")
+    params = RegionalEndpointParameters(
+        sdk_endpoint="https://example.com", region="us-west-2"
+    )
+
+    endpoint = await resolver.resolve_endpoint(params)
+
+    assert endpoint.uri.host == "example.com"

packages/smithy-http/src/smithy_http/aio/endpoints.py

@@ -5,7 +5,7 @@
 from smithy_core import URI
 
 from .. import interfaces as http_interfaces
-from ..endpoints import Endpoint, StaticEndpointParams
+from ..endpoints import Endpoint, StaticEndpointParams, EndpointResolutionError
 from . import interfaces as http_aio_interfaces
 
 
@@ -17,6 +17,11 @@ class StaticEndpointResolver(
     async def resolve_endpoint(
         self, params: StaticEndpointParams
     ) -> http_interfaces.Endpoint:
+        if params.uri is None:
+            raise EndpointResolutionError(
+                "Unable to resolve endpoint: endpoint_uri is required"
+            )
+
         # If it's not a string, it's already a parsed URI so just pass it along.
         if not isinstance(params.uri, str):
             return Endpoint(uri=params.uri)
@@ -27,7 +32,7 @@ async def resolve_endpoint(
 
         # This will end up getting wrapped in the client.
         if parsed.hostname is None:
-            raise ValueError(
+            raise EndpointResolutionError(
                 f"Unable to parse hostname from provided URI: {params.uri}"
             )
 

packages/smithy-http/src/smithy_http/endpoints.py

@@ -2,6 +2,7 @@
 #  SPDX-License-Identifier: Apache-2.0
 from dataclasses import dataclass, field
 
+from smithy_core import SmithyException
 from smithy_core.interfaces import URI
 
 from . import Fields, interfaces
@@ -13,11 +14,14 @@ class Endpoint(interfaces.Endpoint):
     headers: interfaces.Fields = field(default_factory=Fields)
 
 
+class EndpointResolutionError(SmithyException):
+    """Exception type for all exceptions raised by endpoint resolution."""
+
 @dataclass
 class StaticEndpointParams:
     """Static endpoint params.
 
     :param uri: A static URI to route requests to.
     """
 
-    uri: str | URI
+    uri: str | URI | None