[#451] Support Location in CompleteMultipart response

Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>

api/handler/api.go

@@ -41,6 +41,7 @@ type (
 		RetryMaxAttempts() int
 		RetryMaxBackoff() time.Duration
 		RetryStrategy() RetryStrategy
+		Domains() []string
 	}
 
 	FrostFSID interface {

api/handler/handlers_test.go

@@ -72,6 +72,7 @@ type configMock struct {
 	defaultCopiesNumbers          []uint32
 	bypassContentEncodingInChunks bool
 	md5Enabled                    bool
+	domains                       []string
 }
 
 func (c *configMock) DefaultPlacementPolicy(_ string) netmap.PlacementPolicy {
@@ -135,6 +136,10 @@ func (c *configMock) RetryStrategy() RetryStrategy {
 	return RetryStrategyConstant
 }
 
+func (c *configMock) Domains() []string {
+	return c.domains
+}
+
 func prepareHandlerContext(t *testing.T) *handlerContext {
 	return prepareHandlerContextBase(t, layer.DefaultCachesConfigs(zap.NewExample()))
 }

api/handler/multipart_upload.go

@@ -5,7 +5,9 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
+	"path"
 	"strconv"
+	"strings"
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
@@ -30,6 +32,7 @@ type (
 		Bucket   string   `xml:"Bucket"`
 		Key      string   `xml:"Key"`
 		ETag     string   `xml:"ETag"`
+		Location string   `xml:"Location"`
 	}
 
 	ListMultipartUploadsResponse struct {
@@ -426,6 +429,7 @@ func (h *handler) CompleteMultipartUploadHandler(w http.ResponseWriter, r *http.
 		Bucket:   objInfo.Bucket,
 		Key:      objInfo.Name,
 		ETag:     data.Quote(objInfo.ETag(h.cfg.MD5Enabled())),
+		Location: getObjectLocation(r, h.cfg.Domains(), reqInfo.BucketName, reqInfo.ObjectName),
 	}
 
 	if settings.VersioningEnabled() {
@@ -437,6 +441,35 @@ func (h *handler) CompleteMultipartUploadHandler(w http.ResponseWriter, r *http.
 	}
 }
 
+// returns "https" if the tls boolean is true, "http" otherwise.
+func getURLScheme(r *http.Request) string {
+	if r.TLS != nil {
+		return "https"
+	}
+	return "http"
+}
+
+// getObjectLocation gets the fully qualified URL of an object.
+func getObjectLocation(r *http.Request, domains []string, bucket, object string) string {
+	proto := middleware.GetSourceScheme(r)
+	if proto == "" {
+		proto = getURLScheme(r)
+	}
+	u := &url.URL{
+		Host:   r.Host,
+		Path:   path.Join("/", bucket, object),
+		Scheme: proto,
+	}
+	// If domain is set then we need to use bucket DNS style.
+	for _, domain := range domains {
+		if strings.HasPrefix(r.Host, bucket+"."+domain) {
+			u.Path = path.Join("/", object)
+			break
+		}
+	}
+	return u.String()
+}
+
 func (h *handler) completeMultipartUpload(r *http.Request, c *layer.CompleteMultipartParams, bktInfo *data.BucketInfo) (*data.ObjectInfo, error) {
 	ctx := r.Context()
 	uploadData, extendedObjInfo, err := h.obj.CompleteMultipartUpload(ctx, c)

api/handler/multipart_upload_test.go

@@ -441,6 +441,80 @@ func TestUploadPartCheckContentSHA256(t *testing.T) {
 	}
 }
 
+func TestMultipartObjectLocation(t *testing.T) {
+	for _, tc := range []struct {
+		req      *http.Request
+		bucket   string
+		object   string
+		domains  []string
+		expected string
+	}{
+		{
+			req: &http.Request{
+				Host:   "127.0.0.1:8084",
+				Header: map[string][]string{"X-Forwarded-Scheme": {"http"}},
+			},
+			bucket:   "testbucket1",
+			object:   "test/1.txt",
+			expected: "http://127.0.0.1:8084/testbucket1/test/1.txt",
+		},
+		{
+			req: &http.Request{
+				Host:   "localhost:8084",
+				Header: map[string][]string{"X-Forwarded-Scheme": {"https"}},
+			},
+			bucket:   "testbucket1",
+			object:   "test/1.txt",
+			expected: "https://localhost:8084/testbucket1/test/1.txt",
+		},
+		{
+			req: &http.Request{
+				Host:   "s3.mybucket.org",
+				Header: map[string][]string{"X-Forwarded-Scheme": {"http"}},
+			},
+			bucket:   "mybucket",
+			object:   "test/1.txt",
+			expected: "http://s3.mybucket.org/mybucket/test/1.txt",
+		},
+		{
+			req:      &http.Request{Host: "mys3.mybucket.org"},
+			bucket:   "mybucket",
+			object:   "test/1.txt",
+			expected: "http://mys3.mybucket.org/mybucket/test/1.txt",
+		},
+		{
+			req:      &http.Request{Host: "s3.bucket.org", TLS: &tls.ConnectionState{}},
+			bucket:   "bucket",
+			object:   "obj",
+			expected: "https://s3.bucket.org/bucket/obj",
+		},
+		{
+			req: &http.Request{
+				Host: "mybucket.s3dev.frostfs.devenv",
+			},
+			domains:  []string{"s3dev.frostfs.devenv"},
+			bucket:   "mybucket",
+			object:   "test/1.txt",
+			expected: "http://mybucket.s3dev.frostfs.devenv/test/1.txt",
+		},
+		{
+			req: &http.Request{
+				Host:   "mybucket.s3dev.frostfs.devenv",
+				Header: map[string][]string{"X-Forwarded-Scheme": {"https"}},
+			},
+			domains:  []string{"s3dev.frostfs.devenv"},
+			bucket:   "mybucket",
+			object:   "test/1.txt",
+			expected: "https://mybucket.s3dev.frostfs.devenv/test/1.txt",
+		},
+	} {
+		t.Run("", func(t *testing.T) {
+			location := getObjectLocation(tc.req, tc.domains, tc.bucket, tc.object)
+			require.Equal(t, tc.expected, location)
+		})
+	}
+}
+
 func uploadPartCopy(hc *handlerContext, bktName, objName, uploadID string, num int, srcObj string, start, end int) *UploadPartCopyResponse {
 	return uploadPartCopyBase(hc, bktName, objName, false, uploadID, num, srcObj, start, end)
 }

api/middleware/reqinfo.go

@@ -71,6 +71,8 @@ var (
 	// De-facto standard header keys.
 	xForwardedFor    = http.CanonicalHeaderKey("X-Forwarded-For")
 	xRealIP          = http.CanonicalHeaderKey("X-Real-IP")
+	xForwardedProto  = http.CanonicalHeaderKey("X-Forwarded-Proto")
+	xForwardedScheme = http.CanonicalHeaderKey("X-Forwarded-Scheme")
 
 	// RFC7239 defines a new "Forwarded: " header designed to replace the
 	// existing use of X-Forwarded-* headers.
@@ -79,6 +81,9 @@ var (
 	// Allows for a sub-match of the first value after 'for=' to the next
 	// comma, semi-colon or space. The match is case-insensitive.
 	forRegex = regexp.MustCompile(`(?i)(?:for=)([^(;|, )]+)(.*)`)
+	// Allows for a sub-match for the first instance of scheme (http|https)
+	// prefixed by 'proto='. The match is case-insensitive.
+	protoRegex = regexp.MustCompile(`(?i)^(;|,| )+(?:proto=)(https|http)`)
 )
 
 // NewReqInfo returns new ReqInfo based on parameters.
@@ -291,3 +296,31 @@ func getSourceIP(r *http.Request) string {
 	}
 	return raddr
 }
+
+// GetSourceScheme retrieves the scheme from the X-Forwarded-Proto and RFC7239
+// Forwarded headers (in that order).
+func GetSourceScheme(r *http.Request) string {
+	var scheme string
+
+	// Retrieve the scheme from X-Forwarded-Proto.
+	if proto := r.Header.Get(xForwardedProto); proto != "" {
+		scheme = strings.ToLower(proto)
+	} else if proto = r.Header.Get(xForwardedScheme); proto != "" {
+		scheme = strings.ToLower(proto)
+	} else if proto := r.Header.Get(forwarded); proto != "" {
+		// match should contain at least two elements if the protocol was
+		// specified in the Forwarded header. The first element will always be
+		// the 'for=', which we ignore, subsequently we proceed to look for
+		// 'proto=' which should precede right after `for=` if not
+		// we simply ignore the values and return empty. This is in line
+		// with the approach we took for returning first ip from multiple
+		// params.
+		if match := forRegex.FindStringSubmatch(proto); len(match) > 1 {
+			if match = protoRegex.FindStringSubmatch(match[2]); len(match) > 1 {
+				scheme = strings.ToLower(match[2])
+			}
+		}
+	}
+
+	return scheme
+}

cmd/s3-gw/app.go

@@ -107,6 +107,7 @@ type (
 		retryMaxAttempts              int
 		retryMaxBackoff               time.Duration
 		retryStrategy                 handler.RetryStrategy
+		domains                       []string
 	}
 
 	maxClientsConfig struct {
@@ -231,6 +232,7 @@ func (s *appSettings) update(v *viper.Viper, log *zap.Logger) {
 	s.setRetryMaxAttempts(fetchRetryMaxAttempts(v))
 	s.setRetryMaxBackoff(fetchRetryMaxBackoff(v))
 	s.setRetryStrategy(fetchRetryStrategy(v))
+	s.setVHSSettings(v, log)
 }
 
 func (s *appSettings) updateNamespacesSettings(v *viper.Viper, log *zap.Logger) {
@@ -245,6 +247,15 @@ func (s *appSettings) updateNamespacesSettings(v *viper.Viper, log *zap.Logger)
 	s.namespaces = nsConfig.Namespaces
 }
 
+func (s *appSettings) setVHSSettings(v *viper.Viper, _ *zap.Logger) {
+	domains := v.GetStringSlice(cfgListenDomains)
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.domains = domains
+}
+
 func (s *appSettings) BypassContentEncodingInChunks() bool {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
@@ -447,6 +458,12 @@ func (s *appSettings) RetryStrategy() handler.RetryStrategy {
 	return s.retryStrategy
 }
 
+func (s *appSettings) Domains() []string {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	return s.domains
+}
+
 func (a *App) initAPI(ctx context.Context) {
 	a.initLayer(ctx)
 	a.initHandler()
@@ -684,8 +701,7 @@ func (a *App) setHealthStatus() {
 // Serve runs HTTP server to handle S3 API requests.
 func (a *App) Serve(ctx context.Context) {
 	// Attach S3 API:
-	domains := a.cfg.GetStringSlice(cfgListenDomains)
-	a.log.Info(logs.FetchDomainsPrepareToUseAPI, zap.Strings("domains", domains))
+	a.log.Info(logs.FetchDomainsPrepareToUseAPI, zap.Strings("domains", a.settings.Domains()))
 
 	cfg := api.Config{
 		Throttle: middleware.ThrottleOpts{
@@ -696,7 +712,7 @@ func (a *App) Serve(ctx context.Context) {
 		Center:  a.ctr,
 		Log:     a.log,
 		Metrics: a.metrics,
-		Domains: domains,
+		Domains: a.settings.Domains(),
 
 		MiddlewareSettings: a.settings,
 		PolicyChecker:      a.policyStorage,