19088: Export collection/project properties as x-amz-meta tags.

[arvados.git] / services / keep-web / s3.go

diff --git a/services/keep-web/s3.go b/services/keep-web/s3.go
index 59ab3cd4389c0cc57f9a923983ee58e12bca5184..4117dafbc6f248e14cafa41cbfdd0193d1408fc9 100644 (file)
--- a/services/keep-web/s3.go
+++ b/services/keep-web/s3.go
@@ -8,12 +8,14 @@ import (
        "crypto/hmac"
        "crypto/sha256"
        "encoding/base64"
+       "encoding/json"
        "encoding/xml"
        "errors"
        "fmt"
        "hash"
        "io"
        "net/http"
+       "net/textproto"
        "net/url"
        "os"
        "path/filepath"
@@ -385,6 +387,7 @@ func (h *handler) serveS3(w http.ResponseWriter, r *http.Request) bool {
                if r.Method == "HEAD" && !objectNameGiven {
                        // HeadBucket
                        if err == nil && fi.IsDir() {
+                               setFileInfoHeaders(w.Header(), fs, fspath)
                                w.WriteHeader(http.StatusOK)
                        } else if os.IsNotExist(err) {
                                s3ErrorResponse(w, NoSuchBucket, "The specified bucket does not exist.", r.URL.Path, http.StatusNotFound)
@@ -394,6 +397,7 @@ func (h *handler) serveS3(w http.ResponseWriter, r *http.Request) bool {
                        return true
                }
                if err == nil && fi.IsDir() && objectNameGiven && strings.HasSuffix(fspath, "/") && h.Cluster.Collections.S3FolderObjects {
+                       setFileInfoHeaders(w.Header(), fs, fspath)
                        w.Header().Set("Content-Type", "application/x-directory")
                        w.WriteHeader(http.StatusOK)
                        return true
@@ -415,6 +419,7 @@ func (h *handler) serveS3(w http.ResponseWriter, r *http.Request) bool {
                // shallow copy r, and change URL path
                r := *r
                r.URL.Path = fspath
+               setFileInfoHeaders(w.Header(), fs, fspath)
                http.FileServer(fs).ServeHTTP(w, &r)
                return true
        case r.Method == http.MethodPut:
@@ -586,6 +591,48 @@ func (h *handler) serveS3(w http.ResponseWriter, r *http.Request) bool {
        }
 }
 
+func setFileInfoHeaders(header http.Header, fs arvados.CustomFileSystem, path string) {
+       path = strings.TrimSuffix(path, "/")
+       var props map[string]interface{}
+       for {
+               fi, err := fs.Stat(path)
+               if err != nil {
+                       return
+               }
+               switch src := fi.Sys().(type) {
+               case *arvados.Collection:
+                       props = src.Properties
+               case *arvados.Group:
+                       props = src.Properties
+               default:
+                       // Try parent
+                       cut := strings.LastIndexByte(path, '/')
+                       if cut < 0 {
+                               return
+                       }
+                       path = path[:cut]
+                       continue
+               }
+               break
+       }
+       for k, v := range props {
+               if !validMIMEHeaderKey(k) {
+                       continue
+               }
+               k = "x-amz-meta-" + k
+               if s, ok := v.(string); ok {
+                       header.Set(k, s)
+               } else if j, err := json.Marshal(v); err == nil {
+                       header.Set(k, string(j))
+               }
+       }
+}
+
+func validMIMEHeaderKey(k string) bool {
+       check := "z-" + k
+       return check != textproto.CanonicalMIMEHeaderKey(check)
+}
+
 // Call fn on the given path (directory) and its contents, in
 // lexicographic order.
 //