s3 cache client-side support

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/aws/aws-sdk-go-v2/config/defaultsmode.go

@@ -0,0 +1,47 @@
+package config
+
+import (
+	"context"
+	"os"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/feature/ec2/imds"
+)
+
+const execEnvVar = "AWS_EXECUTION_ENV"
+
+// DefaultsModeOptions is the set of options that are used to configure
+type DefaultsModeOptions struct {
+	// The SDK configuration defaults mode. Defaults to legacy if not specified.
+	//
+	// Supported modes are: auto, cross-region, in-region, legacy, mobile, standard
+	Mode aws.DefaultsMode
+
+	// The EC2 Instance Metadata Client that should be used when performing environment
+	// discovery when aws.DefaultsModeAuto is set.
+	//
+	// If not specified the SDK will construct a client if the instance metadata service has not been disabled by
+	// the AWS_EC2_METADATA_DISABLED environment variable.
+	IMDSClient *imds.Client
+}
+
+func resolveDefaultsModeRuntimeEnvironment(ctx context.Context, envConfig *EnvConfig, client *imds.Client) (aws.RuntimeEnvironment, error) {
+	getRegionOutput, err := client.GetRegion(ctx, &imds.GetRegionInput{})
+	// honor context timeouts, but if we couldn't talk to IMDS don't fail runtime environment introspection.
+	select {
+	case <-ctx.Done():
+		return aws.RuntimeEnvironment{}, err
+	default:
+	}
+
+	var imdsRegion string
+	if err == nil {
+		imdsRegion = getRegionOutput.Region
+	}
+
+	return aws.RuntimeEnvironment{
+		EnvironmentIdentifier:     aws.ExecutionEnvironmentID(os.Getenv(execEnvVar)),
+		Region:                    envConfig.Region,
+		EC2InstanceMetadataRegion: imdsRegion,
+	}, nil
+}