Implement S3 Style ErrorCodes and Response

This patchset also brings in lot of cleanup in terms of minioapi codebase

pkg/api/minioapi/minioapi.go

@@ -17,26 +17,12 @@
 package minioapi
 
 import (
-	"bytes"
-	"encoding/json"
-	"encoding/xml"
 	"log"
 	"net/http"
-	"strconv"
-	"strings"
-	"time"
 
 	"github.com/gorilla/mux"
 	mstorage "github.com/minio-io/minio/pkg/storage"
 	"github.com/minio-io/minio/pkg/utils/config"
-	"github.com/minio-io/minio/pkg/utils/crypto/signers"
-)
-
-type contentType int
-
-const (
-	xmlType contentType = iota
-	jsonType
 )
 
 const (
@@ -47,11 +33,6 @@ type minioApi struct {
 	storage mstorage.Storage
 }
 
-type vHandler struct {
-	conf    config.Config
-	handler http.Handler
-}
-
 // No encoder interface exists, so we create one.
 type encoder interface {
 	Encode(v interface{}) error
@@ -77,59 +58,6 @@ func HttpHandler(storage mstorage.Storage) http.Handler {
 	return validateHandler(conf, ignoreUnimplementedResources(mux))
 }
 
-// grab AccessKey from authorization header
-func stripAccessKey(r *http.Request) string {
-	fields := strings.Fields(r.Header.Get("Authorization"))
-	if len(fields) < 2 {
-		return ""
-	}
-	splits := strings.Split(fields[1], ":")
-	if len(splits) < 2 {
-		return ""
-	}
-	return splits[0]
-}
-
-func validateHandler(conf config.Config, h http.Handler) http.Handler {
-	return vHandler{conf, h}
-}
-
-func (h vHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	accessKey := stripAccessKey(r)
-	if accessKey != "" {
-		if err := h.conf.ReadConfig(); err != nil {
-			w.WriteHeader(http.StatusInternalServerError)
-		} else {
-			user := h.conf.GetKey(accessKey)
-			ok, err := signers.ValidateRequest(user, r)
-			if ok {
-				h.handler.ServeHTTP(w, r)
-			} else {
-				w.WriteHeader(http.StatusUnauthorized)
-				w.Write([]byte(err.Error()))
-			}
-		}
-	} else {
-		//No access key found, handle this more appropriately
-		//TODO: Remove this after adding tests to support signature
-		//request
-		h.handler.ServeHTTP(w, r)
-		//Add this line, to reply back for invalid requests
-		//w.WriteHeader(http.StatusUnauthorized)
-		//w.Write([]byte("Authorization header malformed")
-	}
-}
-
-func ignoreUnimplementedResources(h http.Handler) http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if ignoreUnImplementedObjectResources(r) || ignoreUnImplementedBucketResources(r) {
-			w.WriteHeader(http.StatusNotImplemented)
-		} else {
-			h.ServeHTTP(w, r)
-		}
-	})
-}
-
 func (server *minioApi) listBucketsHandler(w http.ResponseWriter, req *http.Request) {
 	vars := mux.Vars(req)
 	prefix, ok := vars["prefix"]
@@ -139,13 +67,36 @@ func (server *minioApi) listBucketsHandler(w http.ResponseWriter, req *http.Requ
 
 	acceptsContentType := getContentType(req)
 	buckets, err := server.storage.ListBuckets(prefix)
-	if err != nil {
-		log.Println(err)
-		w.WriteHeader(http.StatusInternalServerError)
-		return
+	switch err := err.(type) {
+	case nil:
+		{
+			response := generateBucketsListResult(buckets)
+			w.Write(writeObjectHeadersAndResponse(w, response, acceptsContentType))
+		}
+	case mstorage.BucketNameInvalid:
+		{
+			error := errorCodeError(InvalidBucketName)
+			errorResponse := getErrorResponse(error, prefix)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.ImplementationError:
+		{
+			log.Println(err)
+			error := errorCodeError(InternalError)
+			errorResponse := getErrorResponse(error, prefix)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.BackendCorrupted:
+		{
+			log.Println(err)
+			error := errorCodeError(InternalError)
+			errorResponse := getErrorResponse(error, prefix)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
 	}
-	response := generateBucketsListResult(buckets)
-	w.Write(writeObjectHeadersAndResponse(w, response, acceptsContentType))
 }
 
 func (server *minioApi) listObjectsHandler(w http.ResponseWriter, req *http.Request) {
@@ -161,19 +112,40 @@ func (server *minioApi) listObjectsHandler(w http.ResponseWriter, req *http.Requ
 	objects, isTruncated, err := server.storage.ListObjects(bucket, prefix, 1000)
 	switch err := err.(type) {
 	case nil: // success
-		response := generateObjectsListResult(bucket, objects, isTruncated)
-		w.Write(writeObjectHeadersAndResponse(w, response, acceptsContentType))
+		{
+			response := generateObjectsListResult(bucket, objects, isTruncated)
+			w.Write(writeObjectHeadersAndResponse(w, response, acceptsContentType))
+		}
 	case mstorage.BucketNotFound:
-		log.Println(err)
-		w.WriteHeader(http.StatusNotFound)
-		w.Write([]byte(err.Error()))
+		{
+			error := errorCodeError(NoSuchBucket)
+			errorResponse := getErrorResponse(error, bucket)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
 	case mstorage.ImplementationError:
-		log.Println(err)
-		w.WriteHeader(http.StatusInternalServerError)
-		w.Write([]byte(err.Error()))
-	default:
-		w.WriteHeader(http.StatusBadRequest)
-		w.Write([]byte(err.Error()))
+		{
+			// Embed error log on server side
+			log.Println(err)
+			error := errorCodeError(InternalError)
+			errorResponse := getErrorResponse(error, bucket)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.BucketNameInvalid:
+		{
+			error := errorCodeError(InvalidBucketName)
+			errorResponse := getErrorResponse(error, bucket)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.ObjectNameInvalid:
+		{
+			error := errorCodeError(NoSuchKey)
+			errorResponse := getErrorResponse(error, prefix)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
 	}
 }
 
@@ -181,16 +153,38 @@ func (server *minioApi) putBucketHandler(w http.ResponseWriter, req *http.Reques
 	vars := mux.Vars(req)
 	bucket := vars["bucket"]
 	err := server.storage.StoreBucket(bucket)
+
+	acceptsContentType := getContentType(req)
+
 	switch err := err.(type) {
 	case nil:
-		w.Header().Set("Server", "Minio")
-		w.Header().Set("Connection", "close")
+		{
+			w.Header().Set("Server", "Minio")
+			w.Header().Set("Connection", "close")
+		}
 	case mstorage.BucketNameInvalid:
-		w.WriteHeader(http.StatusBadRequest)
-		w.Write([]byte(err.Error()))
+		{
+			error := errorCodeError(InvalidBucketName)
+			errorResponse := getErrorResponse(error, bucket)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
 	case mstorage.BucketExists:
-		w.WriteHeader(http.StatusConflict)
-		w.Write([]byte(err.Error()))
+		{
+			error := errorCodeError(BucketAlreadyExists)
+			errorResponse := getErrorResponse(error, bucket)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.ImplementationError:
+		{
+			// Embed errors log on serve side
+			log.Println(err)
+			error := errorCodeError(InternalError)
+			errorResponse := getErrorResponse(error, bucket)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
 	}
 }
 
@@ -199,6 +193,8 @@ func (server *minioApi) getObjectHandler(w http.ResponseWriter, req *http.Reques
 	bucket := vars["bucket"]
 	object := vars["object"]
 
+	acceptsContentType := getContentType(req)
+
 	metadata, err := server.storage.GetObjectMetadata(bucket, object)
 	switch err := err.(type) {
 	case nil: // success
@@ -211,15 +207,33 @@ func (server *minioApi) getObjectHandler(w http.ResponseWriter, req *http.Reques
 		}
 	case mstorage.ObjectNotFound:
 		{
-			log.Println(err)
-			w.WriteHeader(http.StatusNotFound)
-			w.Write([]byte(err.Error()))
+			error := errorCodeError(NoSuchKey)
+			errorResponse := getErrorResponse(error, "/"+bucket+"/"+object)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
 		}
-	default:
+	case mstorage.ObjectNameInvalid:
 		{
+			error := errorCodeError(NoSuchKey)
+			errorResponse := getErrorResponse(error, "/"+bucket+"/"+object)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.BucketNameInvalid:
+		{
+			error := errorCodeError(InvalidBucketName)
+			errorResponse := getErrorResponse(error, "/"+bucket+"/"+object)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.ImplementationError:
+		{
+			// Embed errors log on serve side
 			log.Println(err)
-			w.WriteHeader(http.StatusInternalServerError)
-			w.Write([]byte(err.Error()))
+			error := errorCodeError(InternalError)
+			errorResponse := getErrorResponse(error, "/"+bucket+"/"+object)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
 		}
 	}
 }
@@ -229,16 +243,35 @@ func (server *minioApi) headObjectHandler(w http.ResponseWriter, req *http.Reque
 	bucket := vars["bucket"]
 	object := vars["object"]
 
+	acceptsContentType := getContentType(req)
+
 	metadata, err := server.storage.GetObjectMetadata(bucket, object)
 	switch err := err.(type) {
 	case nil:
 		writeObjectHeaders(w, metadata)
 	case mstorage.ObjectNotFound:
-		log.Println(err)
-		w.WriteHeader(http.StatusNotFound)
-	default:
-		log.Println(err)
-		w.WriteHeader(http.StatusBadRequest)
+		{
+			error := errorCodeError(NoSuchKey)
+			errorResponse := getErrorResponse(error, "/"+bucket+"/"+object)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.ObjectNameInvalid:
+		{
+			error := errorCodeError(NoSuchKey)
+			errorResponse := getErrorResponse(error, "/"+bucket+"/"+object)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.ImplementationError:
+		{
+			// Embed error log on server side
+			log.Println(err)
+			error := errorCodeError(InternalError)
+			errorResponse := getErrorResponse(error, "/"+bucket+"/"+object)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
 	}
 }
 
@@ -246,41 +279,46 @@ func (server *minioApi) putObjectHandler(w http.ResponseWriter, req *http.Reques
 	vars := mux.Vars(req)
 	bucket := vars["bucket"]
 	object := vars["object"]
+
+	acceptsContentType := getContentType(req)
+
 	err := server.storage.StoreObject(bucket, object, "", req.Body)
-	if err != nil {
-		w.WriteHeader(http.StatusBadRequest)
-		w.Write([]byte(err.Error()))
-		return
+	switch err := err.(type) {
+	case nil:
+		w.Header().Set("Server", "Minio")
+		w.Header().Set("Connection", "close")
+	case mstorage.ImplementationError:
+		{
+			// Embed error log on server side
+			log.Println(err)
+			error := errorCodeError(InternalError)
+			errorResponse := getErrorResponse(error, "/"+bucket+"/"+object)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.BucketNotFound:
+		{
+			error := errorCodeError(NoSuchBucket)
+			errorResponse := getErrorResponse(error, "/"+bucket+"/"+object)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.BucketNameInvalid:
+		{
+			error := errorCodeError(InvalidBucketName)
+			errorResponse := getErrorResponse(error, "/"+bucket+"/"+object)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
+	case mstorage.ObjectExists:
+		{
+			error := errorCodeError(NotImplemented)
+			errorResponse := getErrorResponse(error, "/"+bucket+"/"+object)
+			w.WriteHeader(error.HttpStatusCode)
+			w.Write(writeErrorResponse(w, errorResponse, acceptsContentType))
+		}
 	}
-	w.Header().Set("Server", "Minio")
-	w.Header().Set("Connection", "close")
-}
 
-func writeObjectHeadersAndResponse(w http.ResponseWriter, response interface{}, acceptsType contentType) []byte {
-	var bytesBuffer bytes.Buffer
-	var encoder encoder
-	if acceptsType == xmlType {
-		w.Header().Set("Content-Type", "application/xml")
-		encoder = xml.NewEncoder(&bytesBuffer)
-	} else if acceptsType == jsonType {
-		w.Header().Set("Content-Type", "application/json")
-		encoder = json.NewEncoder(&bytesBuffer)
-	}
-	w.Header().Set("Server", "Minio")
-	w.Header().Set("Connection", "close")
-	encoder.Encode(response)
-	return bytesBuffer.Bytes()
-}
-
-// Write Object Header helper
-func writeObjectHeaders(w http.ResponseWriter, metadata mstorage.ObjectMetadata) {
-	lastModified := metadata.Created.Format(time.RFC1123)
-	w.Header().Set("ETag", metadata.ETag)
-	w.Header().Set("Server", "Minio")
-	w.Header().Set("Last-Modified", lastModified)
-	w.Header().Set("Content-Length", strconv.FormatInt(metadata.Size, 10))
-	w.Header().Set("Content-Type", metadata.ContentType)
-	w.Header().Set("Connection", "close")
 }
 
 func generateBucketsListResult(buckets []mstorage.BucketMetadata) BucketListResponse {
@@ -304,38 +342,6 @@ func generateBucketsListResult(buckets []mstorage.BucketMetadata) BucketListResp
 	return data
 }
 
-//// helpers
-
-// Checks requests for unimplemented resources
-func ignoreUnImplementedBucketResources(req *http.Request) bool {
-	q := req.URL.Query()
-	for name := range q {
-		if unimplementedBucketResourceNames[name] {
-			return true
-		}
-	}
-	return false
-}
-
-func ignoreUnImplementedObjectResources(req *http.Request) bool {
-	q := req.URL.Query()
-	for name := range q {
-		if unimplementedObjectResourceNames[name] {
-			return true
-		}
-	}
-	return false
-}
-
-func getContentType(req *http.Request) contentType {
-	if _, ok := req.Header["Accept"]; ok {
-		if req.Header["Accept"][0] == "application/json" {
-			return jsonType
-		}
-	}
-	return xmlType
-}
-
 // takes a set of objects and prepares the objects for serialization
 // input:
 // bucket name