command/cp: allow overriding bucket region (#270)

Resolves #262

command/cp.go

@@ -131,6 +131,14 @@ var copyCommandFlags = []cli.Flag{
 		Name:  "acl",
 		Usage: "set acl for target: defines granted accesses and their types on different accounts/groups",
 	},
+	&cli.StringFlag{
+		Name:  "source-region",
+		Usage: "set the region of source bucket; the region of the source bucket will be automatically discovered if --source-region is not specified",
+	},
+	&cli.StringFlag{
+		Name:  "destination-region",
+		Usage: "set the region of destination bucket: the region of the destination bucket will be automatically discovered if --destination-region is not specified",
+	},
 }
 
 var copyCommand = &cli.Command{
@@ -167,6 +175,9 @@ var copyCommand = &cli.Command{
 			encryptionMethod: c.String("sse"),
 			encryptionKeyID:  c.String("sse-kms-key-id"),
 			acl:              c.String("acl"),
+			// region settings
+			srcRegion:        c.String("source-region"),
+			dstRegion:        c.String("destination-region"),
 
 			storageOpts: NewStorageOpts(c),
 		}.Run(c.Context)
@@ -193,6 +204,10 @@ type Copy struct {
 	encryptionKeyID  string
 	acl              string
 
+	// region settings
+	srcRegion string
+	dstRegion string
+
 	// s3 options
 	concurrency int
 	partSize    int64
@@ -219,6 +234,10 @@ func (c Copy) Run(ctx context.Context) error {
 		return err
 	}
 
+	// override source region if set
+	if c.srcRegion != "" {
+		c.storageOpts.SetRegion(c.srcRegion)
+	}
 	client, err := storage.NewClient(ctx, srcurl, c.storageOpts)
 	if err != nil {
 		printError(c.fullCommand, c.op, err)
@@ -430,6 +449,10 @@ func (c Copy) doUpload(ctx context.Context, srcurl *url.URL, dsturl *url.URL) er
 		return err
 	}
 
+	// override destination region if set
+	if c.dstRegion != "" {
+		c.storageOpts.SetRegion(c.dstRegion)
+	}
 	dstClient, err := storage.NewRemoteClient(ctx, dsturl, c.storageOpts)
 	if err != nil {
 		return err
@@ -473,6 +496,10 @@ func (c Copy) doUpload(ctx context.Context, srcurl *url.URL, dsturl *url.URL) er
 }
 
 func (c Copy) doCopy(ctx context.Context, srcurl, dsturl *url.URL) error {
+	// override destination region if set
+	if c.dstRegion != "" {
+		c.storageOpts.SetRegion(c.dstRegion)
+	}
 	dstClient, err := storage.NewClient(ctx, dsturl, c.storageOpts)
 	if err != nil {
 		return err

storage/s3.go

@@ -696,8 +696,13 @@ func (sc *SessionCache) newSession(ctx context.Context, opts Options) (*session.
 	// get region of the bucket and create session accordingly. if the region
 	// is not provided, it means we want region-independent session
 	// for operations such as listing buckets, making a new bucket etc.
-	if err := setSessionRegion(ctx, sess, opts.bucket); err != nil {
-		return nil, err
+	// only get bucket region when it is not specified.
+	if opts.region != "" {
+		sess.Config.Region = aws.String(opts.region)
+	} else {
+		if err := setSessionRegion(ctx, sess, opts.bucket); err != nil {
+			return nil, err
+		}
 	}
 
 	sc.sessions[opts] = sess

storage/storage.go

@@ -48,12 +48,13 @@ func NewLocalClient(opts Options) *Filesystem {
 
 func NewRemoteClient(ctx context.Context, url *url.URL, opts Options) (*S3, error) {
 	newOpts := Options{
-		MaxRetries:    opts.MaxRetries,
-		Endpoint:      opts.Endpoint,
-		NoVerifySSL:   opts.NoVerifySSL,
-		DryRun:        opts.DryRun,
+		MaxRetries:  opts.MaxRetries,
+		Endpoint:    opts.Endpoint,
+		NoVerifySSL: opts.NoVerifySSL,
+		DryRun:      opts.DryRun,
 		NoSignRequest: opts.NoSignRequest,
-		bucket:        url.Bucket,
+		bucket:      url.Bucket,
+		region:      opts.region,
 	}
 	return newS3Storage(ctx, newOpts)
 }
@@ -67,12 +68,17 @@ func NewClient(ctx context.Context, url *url.URL, opts Options) (Storage, error)
 
 // Options stores configuration for storage.
 type Options struct {
-	MaxRetries    int
-	Endpoint      string
-	NoVerifySSL   bool
-	DryRun        bool
+	MaxRetries  int
+	Endpoint    string
+	NoVerifySSL bool
+	DryRun      bool
 	NoSignRequest bool
-	bucket        string
+	bucket      string
+	region      string
+}
+
+func (o *Options) SetRegion(region string) {
+	o.region = region
 }
 
 // Object is a generic type which contains metadata for storage items.