UseDualStackEndpoint Endpoint Resolver Support

aws/config.go

@@ -208,8 +208,22 @@ type Config struct {
 	//     svc := s3.New(sess, &aws.Config{
 	//         UseDualStack: aws.Bool(true),
 	//     })
+	//
+	// Deprecated: This option will continue to function for S3 and S3 Control for backwards compatibility.
+	// DualStackEndpoint should be used to enable usage of a service's dual-stack endpoint for all service clients
+	// moving forward. For S3 and S3 Control, when DualStackEndpoint is set to a non-zero value it takes higher
+	// precedence then this option.
 	UseDualStack *bool
 
+	// Sets the resolver to resolve the endpoint as a dual-stack endpoint
+	// for the service.
+	//
+	// When enabled, the resolver may in some cases return an endpoint using either the partition or services
+	// dual-stack endpoint pattern which may not be valid or available. In the event that the service or partition
+	// does not have a default dual-stack pattern, and the client's configured region is not an explicitly modeled
+	// endpoint an error will be returned.
+	DualStackEndpoint endpoints.DualStackEndpoint
+
 	// SleepDelay is an override for the func the SDK will call when sleeping
 	// during the lifecycle of a request. Specifically this will be used for
 	// request delays. This value should only be used for testing. To adjust
@@ -554,6 +568,10 @@ func mergeInConfig(dst *Config, other *Config) {
 		dst.UseDualStack = other.UseDualStack
 	}
 
+	if other.DualStackEndpoint != endpoints.DualStackEndpointUnset {
+		dst.DualStackEndpoint = other.DualStackEndpoint
+	}
+
 	if other.EC2MetadataDisableTimeoutOverride != nil {
 		dst.EC2MetadataDisableTimeoutOverride = other.EC2MetadataDisableTimeoutOverride
 	}

aws/endpoints/decode.go

@@ -82,7 +82,6 @@ func decodeV3Endpoints(modelDef modelDefinition, opts DecodeModelOptions) (Resol
 	for i := 0; i < len(ps); i++ {
 		p := &ps[i]
 		custAddEC2Metadata(p)
-		custAddS3DualStack(p)
 		custRegionalS3(p)
 		custRmIotDataService(p)
 		custFixAppAutoscalingChina(p)
@@ -92,15 +91,6 @@ func decodeV3Endpoints(modelDef modelDefinition, opts DecodeModelOptions) (Resol
 	return ps, nil
 }
 
-func custAddS3DualStack(p *partition) {
-	if !(p.ID == "aws" || p.ID == "aws-cn" || p.ID == "aws-us-gov") {
-		return
-	}
-
-	custAddDualstack(p, "s3")
-	custAddDualstack(p, "s3-control")
-}
-
 func custRegionalS3(p *partition) {
 	if p.ID != "aws" {
 		return
@@ -128,18 +118,6 @@ func custRegionalS3(p *partition) {
 	p.Services["s3"] = service
 }
 
-func custAddDualstack(p *partition, svcName string) {
-	s, ok := p.Services[svcName]
-	if !ok {
-		return
-	}
-
-	s.Defaults.HasDualStack = boxedTrue
-	s.Defaults.DualStackHostname = "{service}.dualstack.{region}.{dnsSuffix}"
-
-	p.Services[svcName] = s
-}
-
 func custAddEC2Metadata(p *partition) {
 	p.Services["ec2metadata"] = service{
 		IsRegionalized:    boxedFalse,
@@ -169,7 +147,7 @@ func custFixAppAutoscalingChina(p *partition) {
 	}
 
 	const expectHostname = `autoscaling.{region}.amazonaws.com`
-	if e, a := s.Defaults.Hostname, expectHostname; e != a {
+	if e, a := expectHostname, s.Defaults.Hostname; e != a {
 		fmt.Printf("custFixAppAutoscalingChina: ignoring customization, expected %s, got %s\n", e, a)
 		return
 	}

aws/endpoints/decode_test.go

@@ -1,3 +1,5 @@
+// +build go1.9
+
 package endpoints
 
 import (
@@ -6,8 +8,7 @@ import (
 )
 
 func TestDecodeEndpoints_V3(t *testing.T) {
-	const v3Doc = `
-{
+	const v3Doc = `{
   "version": 3,
   "partitions": [
     {
@@ -20,7 +21,15 @@ func TestDecodeEndpoints_V3(t *testing.T) {
           "v4"
         ]
       },
+      "dualstackDefaults": {
+        "protocols": [
+          "http",
+          "https"
+        ],
+        "hostname": "{service}.{region}.{dualstackDnsSuffix}"
+      },
       "dnsSuffix": "amazonaws.com",
+      "dualstackDnsSuffix": "aws",
       "partition": "aws",
       "partitionName": "AWS Standard",
       "regionRegex": "^(us|eu|ap|sa|ca)\\-\\w+\\-\\d+$",
@@ -32,13 +41,27 @@ func TestDecodeEndpoints_V3(t *testing.T) {
       "services": {
         "acm": {
           "endpoints": {
-             "ap-northeast-1": {}
-    	  }
+            "ap-northeast-1": {}
+          }
         },
         "s3": {
+          "dualstackDefaults": {
+            "protocols": [
+              "http",
+              "https"
+            ],
+            "hostname": "{service}.dualstack.{region}.{dualstackDnsSuffix}"
+          },
+          "dualstackDnsSuffix": "amazonaws.com",
           "endpoints": {
-             "ap-northeast-1": {}
-    	  }
+            "ap-northeast-1": {}
+          },
+          "dualstackEndpoints": {
+            "us-west-2": {
+              "hostname": "s3.dualstack.us-west-2.amazonaws.com",
+              "signatureVersions": ["s3", "s3v4"]
+            }
+          }
         }
       }
     }
@@ -61,20 +84,37 @@ func TestDecodeEndpoints_V3(t *testing.T) {
 
 	p := resolver.(partitions)[0]
 
-	s3Defaults := p.Services["s3"].Defaults
-	if a, e := s3Defaults.HasDualStack, boxedTrue; a != e {
-		t.Errorf("expect s3 service to have dualstack enabled")
-	}
-	if a, e := s3Defaults.DualStackHostname, "{service}.dualstack.{region}.{dnsSuffix}"; a != e {
-		t.Errorf("expect s3 dualstack host pattern to be %q, got %q", e, a)
+	resolved, err := p.EndpointFor("s3", "us-west-2", func(options *Options) {
+		options.DualStackEndpoint = DualStackEndpointEnabled
+	})
+	if err != nil {
+		t.Fatalf("expect no error, got %v", err)
 	}
 
+	assertEndpoint(t, resolved, "https://s3.dualstack.us-west-2.amazonaws.com", "s3", "us-west-2")
+
 	ec2metaEndpoint := p.Services["ec2metadata"].Endpoints["aws-global"]
 	if a, e := ec2metaEndpoint.Hostname, "169.254.169.254/latest"; a != e {
 		t.Errorf("expect ec2metadata host to be %q, got %q", e, a)
 	}
 }
 
+func assertEndpoint(t *testing.T, endpoint ResolvedEndpoint, expectedURL, expectedSigningName, expectedSigningRegion string) {
+	t.Helper()
+
+	if e, a := expectedURL, endpoint.URL; e != a {
+		t.Errorf("expect %v, got %v", e, a)
+	}
+
+	if e, a := expectedSigningName, endpoint.SigningName; e != a {
+		t.Errorf("expect %v, got %v", e, a)
+	}
+
+	if e, a := expectedSigningRegion, endpoint.SigningRegion; e != a {
+		t.Errorf("expect %v, got %v", e, a)
+	}
+}
+
 func TestDecodeEndpoints_NoPartitions(t *testing.T) {
 	const doc = `{ "version": 3 }`
 

aws/endpoints/endpoints.go

@@ -8,6 +8,22 @@ import (
 	"github.com/aws/aws-sdk-go/aws/awserr"
 )
 
+// DualStackEndpoint is a constant to describe the dual-stack endpoint resolution
+// behavior.
+type DualStackEndpoint uint
+
+const (
+	// DualStackEndpointUnset is the default value behavior for dual-stack endpoint
+	// resolution.
+	DualStackEndpointUnset DualStackEndpoint = iota
+
+	// DualStackEndpointEnabled enable dual-stack endpoint resolution for endpoints.
+	DualStackEndpointEnabled
+
+	// DualStackEndpointDisabled disables dual-stack endpoint resolution for endpoints.
+	DualStackEndpointDisabled
+)
+
 // Options provide the configuration needed to direct how the
 // endpoints will be resolved.
 type Options struct {
@@ -21,8 +37,22 @@ type Options struct {
 	// be returned. This endpoint may not be valid. If StrictMatching is
 	// enabled only services that are known to support dualstack will return
 	// dualstack endpoints.
+	//
+	// Deprecated: This option will continue to function for S3 and S3 Control for backwards compatibility.
+	// DualStackEndpoint should be used to enable usage of a service's dual-stack endpoint for all service clients
+	// moving forward. For S3 and S3 Control, when DualStackEndpoint is set to a non-zero value it takes higher
+	// precedence then this option.
 	UseDualStack bool
 
+	// Sets the resolver to resolve the endpoint as a dual-stack endpoint
+	// for the service.
+	//
+	// When enabled, the resolver may in some cases return an endpoint using either the partition or services
+	// dual-stack endpoint pattern which may not be valid or available. In the event that the service or partition
+	// does not have a default dual-stack pattern, and the client's configured region is not an explicitly modeled
+	// endpoint an error will be returned.
+	DualStackEndpoint DualStackEndpoint
+
 	// Enables strict matching of services and regions resolved endpoints.
 	// If the partition doesn't enumerate the exact service and region an
 	// error will be returned. This option will prevent returning endpoints
@@ -55,6 +85,16 @@ type Options struct {
 	S3UsEast1RegionalEndpoint S3UsEast1RegionalEndpoint
 }
 
+func (o Options) isUseDualStackEndpoint(service string) (v bool) {
+	if o.DualStackEndpoint != DualStackEndpointUnset {
+		return o.DualStackEndpoint == DualStackEndpointEnabled
+	}
+	if service == "s3" || service == "s3-control" {
+		return o.UseDualStack
+	}
+	return false
+}
+
 // STSRegionalEndpoint is an enum for the states of the STS Regional Endpoint
 // options.
 type STSRegionalEndpoint int
@@ -166,10 +206,19 @@ func DisableSSLOption(o *Options) {
 
 // UseDualStackOption sets the UseDualStack option. Can be used as a functional
 // option when resolving endpoints.
+//
+// Deprecated: DualStackEndpointOption should be used to enable usage of a service's dual-stack endpoint.
+// When DualStackEndpoint is set to a non-zero value it takes higher precedence then this option.
 func UseDualStackOption(o *Options) {
 	o.UseDualStack = true
 }
 
+// DualStackEndpointOption sets the DualStackEndpoint option to enabled. Can be used as a functional
+// option when resolving endpoints.
+func DualStackEndpointOption(o *Options) {
+	o.DualStackEndpoint = DualStackEndpointEnabled
+}
+
 // StrictMatchingOption sets the StrictMatching option. Can be used as a functional
 // option when resolving endpoints.
 func StrictMatchingOption(o *Options) {

aws/endpoints/endpoints_test.go

@@ -1,3 +1,5 @@
+// +build go1.9
+
 package endpoints
 
 import "testing"
@@ -109,7 +111,7 @@ func TestEnumServicesEndpoints(t *testing.T) {
 
 	ss := p.Services()
 
-	if a, e := len(ss), 5; a != e {
+	if a, e := len(ss), 6; a != e {
 		t.Errorf("expect %d regions got %d", e, a)
 	}
 
@@ -253,12 +255,13 @@ func TestResolverFunc(t *testing.T) {
 
 func TestOptionsSet(t *testing.T) {
 	var actual Options
-	actual.Set(DisableSSLOption, UseDualStackOption, StrictMatchingOption)
+	actual.Set(DisableSSLOption, UseDualStackOption, StrictMatchingOption, DualStackEndpointOption)
 
 	expect := Options{
-		DisableSSL:     true,
-		UseDualStack:   true,
-		StrictMatching: true,
+		DisableSSL:        true,
+		UseDualStack:      true,
+		DualStackEndpoint: DualStackEndpointEnabled,
+		StrictMatching:    true,
 	}
 
 	if actual != expect {

aws/endpoints/example_test.go

@@ -1,3 +1,5 @@
+// +build go1.9
+
 package endpoints_test
 
 import (