From feea33d5e02944e5aeb43d138b8e3d91b2407f08 Mon Sep 17 00:00:00 2001
From: Chris Lu <chris.lu@gmail.com>
Date: Thu, 19 Jul 2018 01:43:27 -0700
Subject: [PATCH] add HeadBucket

---
 weed/s3api/s3api_bucket_handlers.go | 28 ++++++++++++++++++++++++++++
 weed/s3api/s3api_errors.go          |  6 ++++++
 weed/s3api/s3api_server.go          |  4 ++--
 3 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/weed/s3api/s3api_bucket_handlers.go b/weed/s3api/s3api_bucket_handlers.go
index de77da7c8..ef62d08d9 100644
--- a/weed/s3api/s3api_bucket_handlers.go
+++ b/weed/s3api/s3api_bucket_handlers.go
@@ -136,3 +136,31 @@ func (s3a *S3ApiServer) DeleteBucketHandler(w http.ResponseWriter, r *http.Reque
 
 	writeResponse(w, http.StatusNoContent, nil, mimeNone)
 }
+
+func (s3a *S3ApiServer) HeadBucketHandler(w http.ResponseWriter, r *http.Request) {
+
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+
+	err := s3a.withFilerClient(func(client filer_pb.SeaweedFilerClient) error {
+
+		request := &filer_pb.LookupDirectoryEntryRequest{
+			Directory: s3a.option.BucketsPath,
+			Name:      bucket,
+		}
+
+		glog.V(1).Infof("lookup bucket: %v", request)
+		if _, err := client.LookupDirectoryEntry(context.Background(), request); err != nil {
+			return fmt.Errorf("lookup bucket %s/%s: %v", s3a.option.BucketsPath, bucket, err)
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		writeErrorResponse(w, ErrNoSuchBucket, r.URL)
+		return
+	}
+
+	writeSuccessResponseEmpty(w)
+}
diff --git a/weed/s3api/s3api_errors.go b/weed/s3api/s3api_errors.go
index f6988f5e1..8af024700 100644
--- a/weed/s3api/s3api_errors.go
+++ b/weed/s3api/s3api_errors.go
@@ -32,6 +32,7 @@ const (
 	ErrBucketAlreadyExists
 	ErrBucketAlreadyOwnedByYou
 	ErrInvalidBucketName
+	ErrNoSuchBucket
 	ErrInternalError
 )
 
@@ -63,6 +64,11 @@ var errorCodeResponse = map[ErrorCode]APIError{
 		Description:    "The specified bucket is not valid.",
 		HTTPStatusCode: http.StatusBadRequest,
 	},
+	ErrNoSuchBucket: {
+		Code:           "NoSuchBucket",
+		Description:    "The specified bucket does not exist",
+		HTTPStatusCode: http.StatusNotFound,
+	},
 	ErrInternalError: {
 		Code:           "InternalError",
 		Description:    "We encountered an internal error, please try again.",
diff --git a/weed/s3api/s3api_server.go b/weed/s3api/s3api_server.go
index 267dc29ac..8730f0b88 100644
--- a/weed/s3api/s3api_server.go
+++ b/weed/s3api/s3api_server.go
@@ -46,6 +46,8 @@ func (s3a *S3ApiServer) registerRouter(router *mux.Router) {
 		bucket.Methods("PUT").HandlerFunc(s3a.PutBucketHandler)
 		// DeleteBucket
 		bucket.Methods("DELETE").HandlerFunc(s3a.DeleteBucketHandler)
+		// HeadBucket
+		bucket.Methods("HEAD").HandlerFunc(s3a.HeadBucketHandler)
 
 		/*
 			// HeadObject
@@ -78,8 +80,6 @@ func (s3a *S3ApiServer) registerRouter(router *mux.Router) {
 			bucket.Methods("GET").HandlerFunc(s3a.ListObjectsV2Handler).Queries("list-type", "2")
 			// ListObjectsV1 (Legacy)
 			bucket.Methods("GET").HandlerFunc(s3a.ListObjectsV1Handler)
-			// HeadBucket
-			bucket.Methods("HEAD").HandlerFunc(s3a.HeadBucketHandler)
 			// DeleteMultipleObjects
 			bucket.Methods("POST").HandlerFunc(s3a.DeleteMultipleObjectsHandler).Queries("delete", "")