SDK DefaultsMode Configuration Implementation (#1553)

* SDK Default Configuration Implementation
* Regeneration

aws/config.go

@@ -85,6 +85,16 @@ type Config struct {
 	// See the ClientLogMode type documentation for the complete set of logging modes and available
 	// configuration.
 	ClientLogMode ClientLogMode
+
+	// The configured DefaultsMode. If not specified, service clients will default to legacy.
+	//
+	// Supported modes are: auto, cross-region, in-region, legacy, mobile, standard
+	DefaultsMode DefaultsMode
+
+	// The RuntimeEnvironment configuration, only populated if the DefaultsMode is set to
+	// AutoDefaultsMode and is initialized by `config.LoadDefaultConfig`. You should not
+	// populate this structure programmatically, or rely on the values here within your applications.
+	RuntimeEnvironment RuntimeEnvironment
 }
 
 // NewConfig returns a new Config pointer that can be chained with builder

aws/defaults/auto.go

@@ -0,0 +1,38 @@
+package defaults
+
+import (
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"runtime"
+	"strings"
+)
+
+var getGOOS = func() string {
+	return runtime.GOOS
+}
+
+// ResolveDefaultsModeAuto is used to determine the effective aws.DefaultsMode when the mode
+// is set to aws.AutoDefaultsMode.
+func ResolveDefaultsModeAuto(region string, environment aws.RuntimeEnvironment) aws.DefaultsMode {
+	goos := getGOOS()
+	if goos == "android" || goos == "ios" {
+		return aws.DefaultsModeMobile
+	}
+
+	var currentRegion string
+	if len(environment.EnvironmentIdentifier) > 0 {
+		currentRegion = environment.Region
+	}
+
+	if len(currentRegion) == 0 && len(environment.EC2InstanceMetadataRegion) > 0 {
+		currentRegion = environment.EC2InstanceMetadataRegion
+	}
+
+	if len(region) > 0 && len(currentRegion) > 0 {
+		if strings.EqualFold(region, currentRegion) {
+			return aws.DefaultsModeInRegion
+		}
+		return aws.DefaultsModeCrossRegion
+	}
+
+	return aws.DefaultsModeStandard
+}

aws/defaults/auto_test.go

@@ -0,0 +1,89 @@
+package defaults
+
+import (
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"strconv"
+	"testing"
+)
+
+func TestDetermineDefaultsMode(t *testing.T) {
+	cases := []struct {
+		Region      string
+		GOOS        string
+		Environment aws.RuntimeEnvironment
+		Expected    aws.DefaultsMode
+	}{
+		{
+			Region: "us-east-1",
+			GOOS:   "ios",
+			Environment: aws.RuntimeEnvironment{
+				EnvironmentIdentifier: aws.ExecutionEnvironmentID("AWS_Lambda_java8"),
+				Region:                "us-east-1",
+			},
+			Expected: aws.DefaultsModeMobile,
+		},
+		{
+			Region: "us-east-1",
+			GOOS:   "android",
+			Environment: aws.RuntimeEnvironment{
+				EnvironmentIdentifier: aws.ExecutionEnvironmentID("AWS_Lambda_java8"),
+				Region:                "us-east-1",
+			},
+			Expected: aws.DefaultsModeMobile,
+		},
+		{
+			Region: "us-east-1",
+			Environment: aws.RuntimeEnvironment{
+				EnvironmentIdentifier: aws.ExecutionEnvironmentID("AWS_Lambda_java8"),
+				Region:                "us-east-1",
+			},
+			Expected: aws.DefaultsModeInRegion,
+		},
+		{
+			Region: "us-east-1",
+			Environment: aws.RuntimeEnvironment{
+				EnvironmentIdentifier: aws.ExecutionEnvironmentID("AWS_Lambda_java8"),
+				Region:                "us-west-2",
+			},
+			Expected: aws.DefaultsModeCrossRegion,
+		},
+		{
+			Region: "us-east-1",
+			Environment: aws.RuntimeEnvironment{
+				Region:                    "us-east-1",
+				EC2InstanceMetadataRegion: "us-east-1",
+			},
+			Expected: aws.DefaultsModeInRegion,
+		},
+		{
+			Region: "us-east-1",
+			Environment: aws.RuntimeEnvironment{
+				EC2InstanceMetadataRegion: "us-west-2",
+			},
+			Expected: aws.DefaultsModeCrossRegion,
+		},
+		{
+			Region:      "us-west-2",
+			Environment: aws.RuntimeEnvironment{},
+			Expected:    aws.DefaultsModeStandard,
+		},
+	}
+
+	for i, tt := range cases {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			if len(tt.GOOS) > 0 {
+				orig := getGOOS
+				getGOOS = func() string {
+					return tt.GOOS
+				}
+				defer func() {
+					getGOOS = orig
+				}()
+			}
+			got := ResolveDefaultsModeAuto(tt.Region, tt.Environment)
+			if got != tt.Expected {
+				t.Errorf("expect %v, got %v", tt.Expected, got)
+			}
+		})
+	}
+}

aws/defaults/configuration.go

@@ -0,0 +1,35 @@
+package defaults
+
+import "time"
+
+// Configuration is the set of SDK configuration options that are determined based
+// on the configured DefaultsMode.
+type Configuration struct {
+	// ConnectTimeout is the maximum amount of time a dial will wait for
+	// a connect to complete.
+	//
+	// See https://pkg.go.dev/net#Dialer.Timeout
+	ConnectTimeout *time.Duration
+
+	// TLSNegotiationTimeout specifies the maximum amount of time waiting to
+	// wait for a TLS handshake.
+	//
+	// See https://pkg.go.dev/net/http#Transport.TLSHandshakeTimeout
+	TLSNegotiationTimeout *time.Duration
+}
+
+// GetConnectTimeout returns the ConnectTimeout value, returns false if the value is not set.
+func (c *Configuration) GetConnectTimeout() (time.Duration, bool) {
+	if c.ConnectTimeout == nil {
+		return 0, false
+	}
+	return *c.ConnectTimeout, true
+}
+
+// GetTLSNegotiationTimeout returns the TLSNegotiationTimeout value, returns false if the value is not set.
+func (c *Configuration) GetTLSNegotiationTimeout() (time.Duration, bool) {
+	if c.TLSNegotiationTimeout == nil {
+		return 0, false
+	}
+	return *c.TLSNegotiationTimeout, true
+}

aws/defaults/defaults_test.go

@@ -0,0 +1,58 @@
+package defaults
+
+import (
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"strconv"
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestConfigV1(t *testing.T) {
+	cases := []struct {
+		Mode     aws.DefaultsMode
+		Expected Configuration
+	}{
+		{
+			Mode: aws.DefaultsModeStandard,
+			Expected: Configuration{
+				ConnectTimeout:        aws.Duration(2000 * time.Millisecond),
+				TLSNegotiationTimeout: aws.Duration(2000 * time.Millisecond),
+			},
+		},
+		{
+			Mode: aws.DefaultsModeInRegion,
+			Expected: Configuration{
+				ConnectTimeout:        aws.Duration(1000 * time.Millisecond),
+				TLSNegotiationTimeout: aws.Duration(1000 * time.Millisecond),
+			},
+		},
+		{
+			Mode: aws.DefaultsModeCrossRegion,
+			Expected: Configuration{
+				ConnectTimeout:        aws.Duration(2800 * time.Millisecond),
+				TLSNegotiationTimeout: aws.Duration(2800 * time.Millisecond),
+			},
+		},
+		{
+			Mode: aws.DefaultsModeMobile,
+			Expected: Configuration{
+				ConnectTimeout:        aws.Duration(10000 * time.Millisecond),
+				TLSNegotiationTimeout: aws.Duration(11000 * time.Millisecond),
+			},
+		},
+	}
+
+	for i, tt := range cases {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			got, err := v1TestResolver(tt.Mode)
+			if err != nil {
+				t.Fatalf("expect no error, got %v", err)
+			}
+			if diff := cmp.Diff(tt.Expected, got); len(diff) > 0 {
+				t.Error(diff)
+			}
+		})
+	}
+}

aws/defaults/doc.go

@@ -0,0 +1,2 @@
+// Package defaults provides recommended configuration values for AWS SDKs and CLIs.
+package defaults