From f30c95a301d14d0aa91ba32ea06dc7a3ec906422 Mon Sep 17 00:00:00 2001
From: Nitish Tiwari <nitish@minio.io>
Date: Tue, 1 May 2018 23:06:37 +0530
Subject: [PATCH] Add etcd handling for web-handler methods

---
 cmd/generic-handlers.go          |  2 +-
 cmd/typed-errors.go              |  3 ++
 cmd/web-handlers.go              | 63 +++++++++++++++++++++++++++-----
 docs/federation/lookup/README.md |  2 +-
 4 files changed, 59 insertions(+), 11 deletions(-)

diff --git a/cmd/generic-handlers.go b/cmd/generic-handlers.go
index 3c7d447f9..fe13f60b7 100644
--- a/cmd/generic-handlers.go
+++ b/cmd/generic-handlers.go
@@ -624,7 +624,7 @@ type bucketForwardingHandler struct {
 }
 
 func (f bucketForwardingHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	if globalDNSConfig == nil || globalDomainName == "" {
+	if globalDNSConfig == nil || globalDomainName == "" || guessIsBrowserReq(r) || guessIsHealthCheckReq(r) || guessIsMetricsReq(r) || guessIsRPCReq(r) {
 		f.handler.ServeHTTP(w, r)
 		return
 	}
diff --git a/cmd/typed-errors.go b/cmd/typed-errors.go
index af2de7b6b..f261f2ffc 100644
--- a/cmd/typed-errors.go
+++ b/cmd/typed-errors.go
@@ -67,3 +67,6 @@ var errNotFirstDisk = errors.New("Not first disk")
 
 // error returned by first disk waiting to initialize other servers.
 var errFirstDiskWait = errors.New("Waiting on other disks")
+
+// error returned when a bucket already exists
+var errBucketAlreadyExists = errors.New("Your previous request to create the named bucket succeeded and you already own it")
diff --git a/cmd/web-handlers.go b/cmd/web-handlers.go
index 330122f2d..21e18e7f4 100644
--- a/cmd/web-handlers.go
+++ b/cmd/web-handlers.go
@@ -31,6 +31,7 @@ import (
 	"strings"
 	"time"
 
+	etcd "github.com/coreos/etcd/client"
 	humanize "github.com/dustin/go-humanize"
 	"github.com/gorilla/mux"
 	"github.com/gorilla/rpc/v2/json2"
@@ -135,6 +136,26 @@ func (web *webAPIHandlers) MakeBucket(r *http.Request, args *MakeBucketArgs, rep
 		return toJSONError(errInvalidBucketName)
 	}
 
+	if globalDNSConfig != nil {
+		if _, err := globalDNSConfig.Get(args.BucketName); err != nil {
+			if etcd.IsKeyNotFound(err) {
+				// Proceed to creating a bucket.
+				if err = objectAPI.MakeBucketWithLocation(context.Background(), args.BucketName, globalServerConfig.GetRegion()); err != nil {
+					return toJSONError(err)
+				}
+				if err = globalDNSConfig.Put(args.BucketName); err != nil {
+					objectAPI.DeleteBucket(context.Background(), args.BucketName)
+					return toJSONError(err)
+				}
+
+				reply.UIVersion = browser.UIVersion
+				return nil
+			}
+			return toJSONError(err)
+		}
+		return toJSONError(errBucketAlreadyExists)
+	}
+
 	if err := objectAPI.MakeBucketWithLocation(context.Background(), args.BucketName, globalServerConfig.GetRegion()); err != nil {
 		return toJSONError(err, args.BucketName)
 	}
@@ -176,6 +197,14 @@ func (web *webAPIHandlers) DeleteBucket(r *http.Request, args *RemoveBucketArgs,
 		logger.LogIf(ctx, nerr.Err)
 	}
 
+	if globalDNSConfig != nil {
+		if err := globalDNSConfig.Delete(args.BucketName); err != nil {
+			// Deleting DNS entry failed, attempt to create the bucket again.
+			objectAPI.MakeBucketWithLocation(ctx, args.BucketName, "")
+			return toJSONError(err)
+		}
+	}
+
 	reply.UIVersion = browser.UIVersion
 	return nil
 }
@@ -208,16 +237,32 @@ func (web *webAPIHandlers) ListBuckets(r *http.Request, args *WebGenericArgs, re
 	if authErr != nil {
 		return toJSONError(authErr)
 	}
-	buckets, err := listBuckets(context.Background())
-	if err != nil {
-		return toJSONError(err)
-	}
-	for _, bucket := range buckets {
-		reply.Buckets = append(reply.Buckets, WebBucketInfo{
-			Name:         bucket.Name,
-			CreationDate: bucket.Created,
-		})
+	// If etcd, dns federation configured list buckets from etcd.
+	if globalDNSConfig != nil {
+		dnsBuckets, err := globalDNSConfig.List()
+		if err != nil {
+			return toJSONError(err)
+		}
+		for _, dnsRecord := range dnsBuckets {
+			bucketName := strings.Trim(dnsRecord.Key, "/")
+			reply.Buckets = append(reply.Buckets, WebBucketInfo{
+				Name:         bucketName,
+				CreationDate: dnsRecord.CreationDate,
+			})
+		}
+	} else {
+		buckets, err := listBuckets(context.Background())
+		if err != nil {
+			return toJSONError(err)
+		}
+		for _, bucket := range buckets {
+			reply.Buckets = append(reply.Buckets, WebBucketInfo{
+				Name:         bucket.Name,
+				CreationDate: bucket.Created,
+			})
+		}
 	}
+
 	reply.UIVersion = browser.UIVersion
 	return nil
 }
diff --git a/docs/federation/lookup/README.md b/docs/federation/lookup/README.md
index 2cf7ee553..64bb3e8f1 100644
--- a/docs/federation/lookup/README.md
+++ b/docs/federation/lookup/README.md
@@ -42,7 +42,7 @@ NOTE: `mybucket` only exists on one cluster either `cluster1` or `cluster2` this
 is decided by how `domain.com` gets resolved, if there is a round-robin DNS on `domain.com` then
 it is randomized which cluster might provision the bucket.
 
-TODO: For now the control to create the bucket from a client to the right cluster using `region` paramter
+TODO: For now the control to create the bucket from a client to the right cluster using `region` parameter
 is not implemented yet.