Autodetect bucket region

aws/aws-sdk-go#720

cmd/root.go

@@ -38,13 +38,26 @@ var rootCmd = &cobra.Command{
 			os.Exit(1)
 		}
 
-		if ok := s3.IsBucket(*session, bucketName); !ok {
+		region, err := s3.GetBucketRegion(bucketName)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		session.Session.Config.Region = &region
+
+		ok, err := s3.IsBucket(*session, bucketName)
+		if err != nil {
+			fmt.Printf("%s\n", err)
+			os.Exit(1)
+		}
+
+		if !ok {
 			fmt.Printf("The bucket name `%s` was not found in profile `%s`\n", bucketName, profile)
-			return
-		} else {
-			cli.Grep(session, bucketName, prefix, args[0], ignoreCase)
-			return
+			os.Exit(1)
 		}
+
+		cli.Grep(session, bucketName, prefix, args[0], ignoreCase)
 	},
 }
 

config/aws.go

@@ -1,6 +1,7 @@
 package config
 
 import (
+	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/session"
 )
 
@@ -11,12 +12,18 @@ type AWSSession struct {
 
 // NewAWSParams creates a new AWSSession object
 func NewAWSSession(awsProfile string) (*AWSSession, error) {
-	sess := session.Must(session.NewSessionWithOptions(session.Options{
+	sess, err := session.NewSessionWithOptions(session.Options{
+		Config:            aws.Config{Region: aws.String("us-east-2")},
 		Profile:           awsProfile,
 		SharedConfigState: session.SharedConfigEnable,
-	}))
+	})
+
+	if err != nil {
+		return nil, err
+	}
 
 	return &AWSSession{
 		Session: sess,
 	}, nil
+
 }

s3/validators.go

@@ -1,21 +1,43 @@
 package s3
 
 import (
+	"fmt"
+	"net/http"
+
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/s3"
 	"github.com/dabdada/s3-grep/config"
 )
 
+// Get bucket region: https://github.com/aws/aws-sdk-go/issues/720
+func GetBucketRegion(bucketName string) (string, error) {
+	res, err := http.Head(fmt.Sprintf("https://%s.s3.amazonaws.com", bucketName))
+
+	if err != nil {
+		return "", err
+	}
+
+	defer res.Body.Close()
+
+	header := "X-Amz-Bucket-Region"
+
+	if len(res.Header[header]) == 0 {
+		return "", fmt.Errorf("header not found in response: %s", header)
+	}
+
+	return res.Header.Get(header), nil
+}
+
 // IsBucket validator to ensure bucket is available in profile
-func IsBucket(session config.AWSSession, bucketName string) bool {
+func IsBucket(session config.AWSSession, bucketName string) (bool, error) {
 	svc := s3.New(session.Session)
 	headInput := &s3.HeadBucketInput{
 		Bucket: aws.String(bucketName),
 	}
 	_, err := svc.HeadBucket(headInput)
 
 	if err != nil {
-		return false
+		return false, err
 	}
-	return true
+	return true, err
 }