fix return appropriate error for MakeBucket in federation (#8878)

README.md

@@ -21,7 +21,7 @@ docker run -p 9000:9000 minio/minio:edge server /data
 > NOTE: Docker will not display the default keys unless you start the container with the `-it`(interactive TTY) argument. Generally, it is not recommended to use default keys with containers. Please visit MinIO Docker quickstart guide for more information [here](https://docs.min.io/docs/minio-docker-quickstart-guide)
 
 ## macOS
-### Homebrew
+### Homebrew (recommended)
 Install minio packages using [Homebrew](http://brew.sh/)
 ```sh
 brew install minio/stable/minio
@@ -74,7 +74,7 @@ minio.exe server D:\Photos
 
 ## FreeBSD
 ### Port
-Install minio packages using [pkg](https://github.com/freebsd/pkg)
+Install minio packages using [pkg](https://github.com/freebsd/pkg), MinIO doesn't officially build FreeBSD binaries but is maintained by FreeBSD upstream [here](https://www.freshports.org/www/minio).
 
 ```sh
 pkg install minio

cmd/bucket-handlers.go

@@ -534,7 +534,8 @@ func (api objectAPIHandlers) PutBucketHandler(w http.ResponseWriter, r *http.Req
 	}
 
 	if globalDNSConfig != nil {
-		if _, err := globalDNSConfig.Get(bucket); err != nil {
+		sr, err := globalDNSConfig.Get(bucket)
+		if err != nil {
 			if err == dns.ErrNoEntriesFound {
 				// Proceed to creating a bucket.
 				if err = objectAPI.MakeBucketWithLocation(ctx, bucket, location); err != nil {
@@ -567,7 +568,15 @@ func (api objectAPIHandlers) PutBucketHandler(w http.ResponseWriter, r *http.Req
 			return
 
 		}
-		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrBucketAlreadyOwnedByYou), r.URL, guessIsBrowserReq(r))
+		apiErr := ErrBucketAlreadyExists
+		if !globalDomainIPs.Intersection(set.CreateStringSet(getHostsSlice(sr)...)).IsEmpty() {
+			apiErr = ErrBucketAlreadyOwnedByYou
+		}
+		// No IPs seem to intersect, this means that bucket exists but has
+		// different IP addresses perhaps from a different deployment.
+		// bucket names are globally unique in federation at a given
+		// path prefix, name collision is not allowed. Return appropriate error.
+		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(apiErr), r.URL, guessIsBrowserReq(r))
 		return
 	}