Streamline handling of CORS preflight requests.

Also shift HTTP method checks into the HandleFunc declaration.
ArtifactDB · Jan 22, 2025 · a29f8d8 · a29f8d8
1 parent 6126f72
commit a29f8d8
Showing 1 changed file with 12 additions and 45 deletions.
diff --git a/main.go b/main.go
@@ -41,18 +41,6 @@ func dumpHttpErrorResponse(w http.ResponseWriter, err error, path string) {
     dumpJsonResponse(w, status_code, map[string]interface{}{ "status": "ERROR", "reason": message }, path)
 }
 
-func configureCors(w http.ResponseWriter, r *http.Request) bool {
-    if r.Method == "OPTIONS" {
-        w.Header().Set("Access-Control-Allow-Methods", "GET, OPTIONS")
-        w.Header().Set("Access-Control-Allow-Origin", "*")
-        w.Header().Set("Access-Control-Allow-Headers", "*")
-        w.WriteHeader(http.StatusNoContent)
-        return true
-    } else {
-        return false
-    }
-}
-
 /***************************************************/
 
 func main() {
@@ -181,26 +169,12 @@ func main() {
     fs := http.FileServer(http.Dir(globals.Registry))
     fetch_endpt := endpt_prefix + "/fetch/"
     fs_stripped := http.StripPrefix(fetch_endpt, fs)
-    http.HandleFunc(fetch_endpt, func(w http.ResponseWriter, r *http.Request) {
-        if configureCors(w, r) {
-            return
-        }
-        if r.Method != "GET" {
-            w.WriteHeader(http.StatusMethodNotAllowed)
-            return
-        }
+    http.HandleFunc("GET " + fetch_endpt, func(w http.ResponseWriter, r *http.Request) {
+        w.Header().Set("Access-Control-Allow-Origin", "*")
         fs_stripped.ServeHTTP(w, r)
     })
 
-    http.HandleFunc(endpt_prefix + "/list", func(w http.ResponseWriter, r *http.Request) {
-        if configureCors(w, r) {
-            return
-        }
-        if r.Method != "GET" {
-            w.WriteHeader(http.StatusMethodNotAllowed)
-            return
-        }
-
+    http.HandleFunc("GET " + endpt_prefix + "/list", func(w http.ResponseWriter, r *http.Request) {
         listing, err := listFilesHandler(r, globals.Registry)
         if err != nil {
             dumpHttpErrorResponse(w, err, "list request") 
@@ -210,28 +184,21 @@ func main() {
     })
 
     // Creating some useful endpoints. 
-    http.HandleFunc(endpt_prefix + "/info", func(w http.ResponseWriter, r *http.Request) {
-        if configureCors(w, r) {
-            return
-        }
-        if r.Method != "GET" {
-            w.WriteHeader(http.StatusMethodNotAllowed)
-            return
-        }
+    http.HandleFunc("GET " + endpt_prefix + "/info", func(w http.ResponseWriter, r *http.Request) {
         dumpJsonResponse(w, http.StatusOK, map[string]string{ "staging": staging, "registry": globals.Registry }, "info request")
     })
 
-    http.HandleFunc(endpt_prefix + "/", func(w http.ResponseWriter, r *http.Request) {
-        if configureCors(w, r) {
-            return
-        }
-        if r.Method != "GET" {
-            w.WriteHeader(http.StatusMethodNotAllowed)
-            return
-        }
+    http.HandleFunc("GET " + endpt_prefix + "/", func(w http.ResponseWriter, r *http.Request) {
         dumpJsonResponse(w, http.StatusOK, map[string]string{ "name": "gobbler API", "url": "https://github.com/ArtifactDB/gobbler" }, "default request")
     })
 
+    http.HandleFunc("OPTIONS /", func(w http.ResponseWriter, r *http.Request) {
+        w.Header().Set("Access-Control-Allow-Methods", "GET, OPTIONS")
+        w.Header().Set("Access-Control-Allow-Origin", "*")
+        w.Header().Set("Access-Control-Allow-Headers", "*")
+        w.WriteHeader(http.StatusNoContent)
+    })
+
     // Adding a per-day job that purges various old files.
 	ticker := time.NewTicker(time.Hour * 24)
 	defer ticker.Stop()