feat(api): mqtt conn info

backend/services/controller/go.mod

@@ -30,5 +30,6 @@ require (
 	github.com/xdg-go/stringprep v1.0.3 // indirect
 	github.com/youmark/pkcs8 v0.0.0-20181117223130-1be2e3e5546d // indirect
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect
+	golang.org/x/sys v0.13.0 // indirect
 	golang.org/x/text v0.13.0 // indirect
 )

backend/services/controller/go.sum

@@ -71,6 +71,8 @@ golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.13.0 h1:Af8nKPmuFypiUBjVoU9V20FiaFXOcuZI21p0ycVYYGE=
+golang.org/x/sys v0.13.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=

backend/services/controller/internal/api/api.go

@@ -50,6 +50,7 @@ func StartApi(a Api) {
 	authentication.HandleFunc("/admin/register", a.registerAdminUser).Methods("POST")
 	authentication.HandleFunc("/admin/exists", a.adminUserExists).Methods("GET")
 	iot := r.PathPrefix("/api/device").Subrouter()
+	//TODO: create query for devices
 	iot.HandleFunc("", a.retrieveDevices).Methods("GET")
 	iot.HandleFunc("/{sn}/get", a.deviceGetMsg).Methods("PUT")
 	iot.HandleFunc("/{sn}/add", a.deviceCreateMsg).Methods("PUT")
@@ -60,18 +61,24 @@ func StartApi(a Api) {
 	iot.HandleFunc("/{sn}/operate", a.deviceOperateMsg).Methods("PUT")
 	iot.HandleFunc("/{sn}/fw_update", a.deviceFwUpdate).Methods("PUT")
 	iot.HandleFunc("/{sn}/wifi", a.deviceWifi).Methods("PUT", "GET")
+	mtp := r.PathPrefix("/api/mtp").Subrouter()
+	mtp.HandleFunc("/mqtt", a.MqttInfo).Methods("GET")
+	users := r.PathPrefix("/api/users").Subrouter()
+	users.HandleFunc("", a.retrieveUsers).Methods("GET")
 
-	// Middleware for requests which requires user to be authenticated
+	/* ----- Middleware for requests which requires user to be authenticated ---- */
 	iot.Use(func(handler http.Handler) http.Handler {
 		return middleware.Middleware(handler)
 	})
 
-	users := r.PathPrefix("/api/users").Subrouter()
-	users.HandleFunc("", a.retrieveUsers).Methods("GET")
+	mtp.Use(func(handler http.Handler) http.Handler {
+		return middleware.Middleware(handler)
+	})
 
 	users.Use(func(handler http.Handler) http.Handler {
 		return middleware.Middleware(handler)
 	})
+	/* -------------------------------------------------------------------------- */
 
 	// Verifies CORS configs for requests
 	corsOpts := cors.GetCorsConfig()

backend/services/controller/internal/api/mtp.go

@@ -0,0 +1,55 @@
+package api
+
+import (
+	"encoding/json"
+	"net"
+	"net/http"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+type mqttInfo struct {
+	Rtt time.Duration
+}
+
+func (a *Api) MqttInfo(w http.ResponseWriter, r *http.Request) {
+	//TODO: address with value from env or something like that
+	conn, err := net.Dial("tcp", "127.0.0.1:1883")
+	if err != nil {
+		json.NewEncoder(w).Encode("Error to connect to broker")
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	defer conn.Close()
+
+	info, err := tcpInfo(conn.(*net.TCPConn))
+	if err != nil {
+		json.NewEncoder(w).Encode("Error to get TCP socket info")
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	rtt := time.Duration(info.Rtt) * time.Microsecond
+	json.NewEncoder(w).Encode(mqttInfo{
+		Rtt: rtt / 1000,
+	})
+}
+
+func tcpInfo(conn *net.TCPConn) (*unix.TCPInfo, error) {
+	raw, err := conn.SyscallConn()
+	if err != nil {
+		return nil, err
+	}
+
+	var info *unix.TCPInfo
+	ctrlErr := raw.Control(func(fd uintptr) {
+		info, err = unix.GetsockoptTCPInfo(int(fd), unix.IPPROTO_TCP, unix.TCP_INFO)
+	})
+	switch {
+	case ctrlErr != nil:
+		return nil, ctrlErr
+	case err != nil:
+		return nil, err
+	}
+	return info, nil
+}