feat(global): introduce user teams and new UAC system (#868)

api/http/error/error.go

@@ -0,0 +1,30 @@
+package error
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"strings"
+)
+
+// errorResponse is a generic response for sending a error.
+type errorResponse struct {
+	Err string `json:"err,omitempty"`
+}
+
+// WriteErrorResponse writes an error message to the response and logger.
+func WriteErrorResponse(w http.ResponseWriter, err error, code int, logger *log.Logger) {
+	if logger != nil {
+		logger.Printf("http error: %s (code=%d)", err, code)
+	}
+
+	w.WriteHeader(code)
+	json.NewEncoder(w).Encode(&errorResponse{Err: err.Error()})
+}
+
+// WriteMethodNotAllowedResponse writes an error message to the response and sets the Allow header.
+func WriteMethodNotAllowedResponse(w http.ResponseWriter, allowedMethods []string) {
+	w.Header().Set("Allow", strings.Join(allowedMethods, ", "))
+	w.WriteHeader(http.StatusMethodNotAllowed)
+	json.NewEncoder(w).Encode(&errorResponse{Err: http.StatusText(http.StatusMethodNotAllowed)})
+}