Endpoint resolution v2: builtin parameter values (#2759)

* EndpointsResolverv2 builtins

* test coverage for ClientArgsCreator._should_set_global_sts_endpoint

* unit tests for endpoint resolver v2 builtins value lookup

* add typing information for EndpointResolverBuiltins

* PR review code style suggestions

* remove tests for _should_set_global_sts_endpoint

* rename to "compute_endpoint_resolver_builtin_defaults"

* refactor tests to avoid mocking private methods

* remove duplicate import

* cannot request fips or dualstack if SDK::Endpoint is set

* remove incorrect enum type annotations

botocore/args.py

@@ -26,6 +26,7 @@
 import botocore.utils
 from botocore.config import Config
 from botocore.endpoint import EndpointCreator
+from botocore.regions import EndpointResolverBuiltins as EPRBuiltins
 from botocore.signers import RequestSigner
 
 logger = logging.getLogger(__name__)
@@ -344,8 +345,10 @@ def _compute_sts_endpoint_config(self, **resolve_endpoint_kwargs):
     def _should_set_global_sts_endpoint(
         self, region_name, endpoint_url, endpoint_config
     ):
-        endpoint_variant_tags = endpoint_config['metadata'].get('tags')
-        if endpoint_url or endpoint_variant_tags:
+        has_variant_tags = endpoint_config and endpoint_config.get(
+            'metadata', {}
+        ).get('tags')
+        if endpoint_url or has_variant_tags:
             return False
         return (
             self._get_sts_regional_endpoints_config() == 'legacy'
@@ -464,3 +467,67 @@ def _ensure_boolean(self, val):
             return val
         else:
             return val.lower() == 'true'
+
+    def compute_endpoint_resolver_builtin_defaults(
+        self,
+        region_name,
+        service_name,
+        s3_config,
+        endpoint_bridge,
+        client_endpoint_url,
+        legacy_endpoint_url,
+    ):
+        # EndpointResolverv2 rulesets may accept an "SDK::Endpoint" as input.
+        # If the endpoint_url argument of create_client() is set, it always
+        # takes priority.
+        if client_endpoint_url:
+            given_endpoint = client_endpoint_url
+        # If an endpoints.json data file other than the one bundled within
+        # the botocore/data directory is used, the output of legacy
+        # endpoint resolution is provided to EndpointResolverv2.
+        elif not endpoint_bridge.endpoint_resolver.uses_builtin_data:
+            given_endpoint = legacy_endpoint_url
+        else:
+            given_endpoint = None
+
+        return {
+            EPRBuiltins.AWS_REGION: region_name,
+            EPRBuiltins.AWS_USE_FIPS: (
+                endpoint_bridge._resolve_endpoint_variant_config_var(
+                    'use_fips_endpoint'
+                )
+                or False
+                and not given_endpoint
+            ),
+            EPRBuiltins.AWS_USE_DUALSTACK: (
+                endpoint_bridge._resolve_use_dualstack_endpoint(service_name)
+                or False
+                and not given_endpoint
+            ),
+            EPRBuiltins.AWS_STS_USE_GLOBAL_ENDPOINT: (
+                self._should_set_global_sts_endpoint(
+                    region_name=region_name,
+                    endpoint_url=None,
+                    endpoint_config=None,
+                )
+            ),
+            EPRBuiltins.AWS_S3_USE_GLOBAL_ENDPOINT: (
+                self._should_force_s3_global(region_name, s3_config)
+            ),
+            EPRBuiltins.AWS_S3_ACCELERATE: s3_config.get(
+                'use_accelerate_endpoint', False
+            ),
+            EPRBuiltins.AWS_S3_FORCE_PATH_STYLE: (
+                s3_config.get('addressing_style') == 'path'
+            ),
+            EPRBuiltins.AWS_S3_USE_ARN_REGION: s3_config.get(
+                'use_arn_region', True
+            ),
+            EPRBuiltins.AWS_S3CONTROL_USE_ARN_REGION: s3_config.get(
+                'use_arn_region', False
+            ),
+            EPRBuiltins.AWS_S3_DISABLE_MRAP: s3_config.get(
+                's3_disable_multiregion_access_points', False
+            ),
+            EPRBuiltins.SDK_ENDPOINT: given_endpoint,
+        }

botocore/regions.py

@@ -18,6 +18,7 @@
 """
 import logging
 import re
+from enum import Enum
 
 from botocore.exceptions import (
     EndpointVariantError,
@@ -401,3 +402,34 @@ def _expand_template(
         return template.format(
             service=service_name, region=endpoint_name, dnsSuffix=dnsSuffix
         )
+
+
+class EndpointResolverBuiltins(str, Enum):
+    # The AWS Region configured for the SDK client (str)
+    AWS_REGION = "AWS::Region"
+    # Whether the UseFIPSEndpoint configuration option has been enabled for
+    # the SDK client (bool)
+    AWS_USE_FIPS = "AWS::UseFIPS"
+    # Whether the UseDualStackEndpoint configuration option has been enabled
+    # for the SDK client (bool)
+    AWS_USE_DUALSTACK = "AWS::UseDualStack"
+    # Whether the global endpoint should be used with STS, rather the the
+    # regional endpoint for us-east-1 (bool)
+    AWS_STS_USE_GLOBAL_ENDPOINT = "AWS::STS::UseGlobalEndpoint"
+    # Whether the global endpoint should be used with S3, rather then the
+    # regional endpoint for us-east-1 (bool)
+    AWS_S3_USE_GLOBAL_ENDPOINT = "AWS::S3::UseGlobalEndpoint"
+    # Whether S3 Transfer Acceleration has been requested (bool)
+    AWS_S3_ACCELERATE = "AWS::S3::Accelerate"
+    # Whether S3 Force Path Style has been enabled (bool)
+    AWS_S3_FORCE_PATH_STYLE = "AWS::S3::ForcePathStyle"
+    # Whether to use the ARN region or raise an error when ARN and client
+    # region differ (for s3 service only, bool)
+    AWS_S3_USE_ARN_REGION = "AWS::S3::UseArnRegion"
+    # Whether to use the ARN region or raise an error when ARN and client
+    # region differ (for s3-control service only, bool)
+    AWS_S3CONTROL_USE_ARN_REGION = 'AWS::S3Control::UseArnRegion'
+    # Whether multi-region access points (MRAP) should be disabled (bool)
+    AWS_S3_DISABLE_MRAP = "AWS::S3::DisableMultiRegionAccessPoints"
+    # Whether a custom endpoint has been configured (str)
+    SDK_ENDPOINT = "SDK::Endpoint"