Issue #951 Send errors back encoded as JSON

Add a new commandError struct to report
command errors and json encoding errors

Author: anjannath

pkg/crc/api/api.go

@@ -50,12 +50,13 @@ func (api CrcApiServer) handleClusterOperations() {
 
 func (api CrcApiServer) handleRequest(req commandRequest, conn net.Conn) {
 	defer conn.Close()
+	var result string
 	if handler, ok := api.handlers[req.Command]; ok {
-		result := handler(req.Args)
-		writeStringToSocket(conn, result)
+		result = handler(req.Args)
 	} else {
-		writeStringToSocket(conn, fmt.Sprintf("Unknown command supplied: %s", req.Command))
+		result = encodeErrorToJson(fmt.Sprintf("Unknown command supplied: %s", req.Command))
 	}
+	writeStringToSocket(conn, result)
 }
 
 func (api CrcApiServer) handleConnections(conn net.Conn) {
@@ -84,7 +85,8 @@ func (api CrcApiServer) handleConnections(conn net.Conn) {
 		if !addRequestToChannel(r, api.clusterOpsRequestsChan) {
 			defer conn.Close()
 			logging.Error("Channel capacity reached, unable to add new request")
-			writeStringToSocket(conn, "Channel capacity reached, unable to add new request")
+			errMsg := encodeErrorToJson("Sockets channel capacity reached, unable to add new request")
+			writeStringToSocket(conn, errMsg)
 			return
 		}
 	} else {

pkg/crc/api/handlers.go

@@ -80,7 +80,18 @@ func encodeStructToJson(v interface{}) string {
 	s, err := json.Marshal(v)
 	if err != nil {
 		logging.Error(err.Error())
-		return "Failed"
+		err := commandError{
+			Err: "Failed while encoding JSON to string",
+		}
+		s, _ := json.Marshal(err)
+		return string(s)
 	}
 	return string(s)
 }
+
+func encodeErrorToJson(errMsg string) string {
+	err := commandError{
+		Err: errMsg,
+	}
+	return encodeStructToJson(err)
+}

pkg/crc/api/types.go

@@ -7,6 +7,10 @@ import (
 type ArgsType map[string]string
 type handlerFunc func(ArgsType) string
 
+type commandError struct {
+	Err string
+}
+
 type CrcApiServer struct {
 	listener               net.Listener
 	clusterOpsRequestsChan chan clusterOpsRequest