Added in gRPC-web support and boilerplate code for a client

P4wnP1_service.go

@@ -40,5 +40,5 @@ func main() {
 
 	service.InitLed(false) //Set LED to manual trigger
 	service.InitDefaultLEDSettings()
-	service.StartRpcServer("", "50051") //start gRPC service
+	service.StartRpcServerAndWeb("0.0.0.0", "50051") //start gRPC service
 }

b_proto.sh

@@ -1,2 +1,7 @@
 #!/bin/bash
+# golang version
 protoc -I proto/ proto/grpc.proto --go_out=plugins=grpc:proto
+
+# gopherjs version
+protoc -I proto/ proto/grpc.proto --gopherjs_out=plugins=grpc:proto/gopherjs
+

cli_client/cmd_usb.go

@@ -144,7 +144,6 @@ func cobraUsbSet(cmd *cobra.Command, args []string) {
 		}
 	}
 
-	//ToDo: Implement detailed UMS settings
 	if (cmd.Flags().Lookup("ums").Changed) {
 		if tmpUseUMS == 0 {
 			fmt.Println("Disabeling USB Mass Storage")
@@ -171,9 +170,9 @@ func cobraUsbSet(cmd *cobra.Command, args []string) {
 
 
 	//Try to set the change config
-	//ToDo: Adopt parsing of Error Message to other gRPC calls
 	err = ClientSetGadgetSettings(StrRemoteHost, StrRemotePort, *gs)
 	if err != nil {
+		//ToDo: Adopt parsing of Error Message to other gRPC calls
 		log.Printf("Error setting new gadget settings: %v\n", status.Convert(err).Message())
 		return
 	}

install.sh

@@ -6,3 +6,6 @@ export PATH=$PATH:/usr/local/go/bin # put into ~/.profile
 echo export PATH=$PATH:/usr/local/go/bin >> ~/.profile
 sudo bash -c 'echo export PATH=\$PATH:/usr/local/go/bin >> ~/.profile'
 go get google.golang.org/grpc
+
+go get -u github.com/improbable-eng/grpc-web/go/grpcweb
+go get -u github.com/gorilla/websocket

service/rpc_server.go

@@ -11,6 +11,12 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"github.com/improbable-eng/grpc-web/go/grpcweb"
+
+	"net/http"
+	"strings"
+	"path"
+	"time"
 )
 
 type server struct {}
@@ -108,3 +114,101 @@ func StartRpcServer(host string, port string) {
 		log.Fatalf("Failed to serve: %v", err)
 	}
 }
+
+func folderReader(fn http.Handler) http.HandlerFunc {
+	return func(w http.ResponseWriter, req *http.Request) {
+		if strings.HasSuffix(req.URL.Path, "/") {
+			// Use contents of index.html for directory, if present.
+			req.URL.Path = path.Join(req.URL.Path, "index.html")
+		}
+		fn.ServeHTTP(w, req)
+	}
+}
+
+func StartRpcWebServer(host string, port string) {
+	//Create gRPC Server
+	s := grpc.NewServer()
+	pb.RegisterP4WNP1Server(s, &server{})
+
+	//grpc_web_srv := grpcweb.WrapServer(s, grpcweb.WithWebsockets(true)) //Wrap server to improbable grpc-web with websockets
+	grpc_web_srv := grpcweb.WrapServer(s) //Wrap server to improbable grpc-web with websockets
+
+	/*
+	http_handler := func(resp http.ResponseWriter, req *http.Request) {
+		if req.ProtoMajor == 2 && strings.Contains(req.Header.Get("Content-Type"), "application/grpc") ||
+			websocket.IsWebSocketUpgrade(req) {
+			grpc_web_srv.ServeHTTP(resp, req)
+		} else {
+			//No gRPC request
+			folderReader(http.FileServer(http.Dir("/home/pi/P4wnP1_go"))).ServeHTTP(resp, req)
+		}
+	}
+	*/
+
+	http_handler := func(resp http.ResponseWriter, req *http.Request) {
+		grpc_web_srv.ServeHTTP(resp, req)
+	}
+
+	listen_address := host + ":" + port
+	http_srv := &http.Server{
+		Addr: listen_address,
+		Handler: http.HandlerFunc(http_handler),
+		//ReadHeaderTimeout: 5*time.Second,
+		//IdleTimeout: 120*time.Second,
+	}
+
+
+	//Open TCP listener
+	log.Printf("P4wnP1 gRPC-web server listening on " + listen_address)
+	log.Fatal(http_srv.ListenAndServe())
+}
+
+func StartRpcServerAndWeb(host string, port string) {
+	listen_address := host + ":" + port
+	webserver_path := "/home/pi/P4wnP1_go/www" //ToDo: Change this to an absolute path which could be used after installation
+
+	//Create gRPC Server
+	s := grpc.NewServer()
+	pb.RegisterP4WNP1Server(s, &server{})
+
+	//Wrap the server into a gRPC-web server
+	grpc_web_srv := grpcweb.WrapServer(s) //Wrap server to improbable grpc-web with websockets
+	//define a handler for a HTTP web server using the gRPC-web proxy
+	http_gRPC_web_handler := func(resp http.ResponseWriter, req *http.Request) {
+		if strings.Contains(req.Header.Get("Content-Type"), "application/grpc") || req.Method == "OPTIONS" {
+			fmt.Printf("gRPC-web req:\n %v\n", req)
+			grpc_web_srv.ServeHTTP(resp, req) // if content type indicates grpc or REQUEST METHOD IS OPTIONS (pre-flight) serve gRPC-web
+		} else {
+			fmt.Printf("legacy web req:\n %v\n", req)
+			http.FileServer(http.Dir((webserver_path))).ServeHTTP(resp, req)
+		}
+	}
+
+	//Open TCP listener
+	log.Printf("P4wnP1 gRPC server listening on " + listen_address)
+	lis, err := net.Listen("tcp", listen_address)
+	if err != nil {
+		log.Fatalf("failed to listen: %v", err)
+	}
+
+	// run gRPC server in go routine
+	go func() {
+		if err := s.Serve(lis); err != nil {
+			log.Fatalf("Failed to serve: %v", err)
+		}
+	}()
+
+	//Setup our HTTP server
+	http_srv := &http.Server{
+		Addr: host + ":80", //listen on port 80 with webservice
+		Handler: http.HandlerFunc(http_gRPC_web_handler),
+		ReadHeaderTimeout: 5*time.Second,
+		IdleTimeout: 120*time.Second,
+	}
+	log.Printf("P4wnP1 gRPC-web server listening on " + http_srv.Addr)
+	err_http := http_srv.ListenAndServe()
+	if err_http != nil {
+		log.Fatal(err)
+	}
+
+}

web_client/build.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+# dependencies for the web app
+gopherjs build -o ../www/webapp.js main.go

web_client/deps.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+# dependencies for the web app
+go get -u honnef.co/go/js/dom

web_client/index.html

@@ -0,0 +1,8 @@
+<html>
+    <head>
+        <title>gRPC test</title>
+    </head>
+    <body>
+        <script src="main.js"></script>
+    </body>
+</html>

web_client/install.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+# Install gopherjs-gRPC plugin by Johan Brandhorst
+
+# go and protoc have to be installed already
+# $GOPATH/bin has to be in path
+
+go get -u github.com/gopherjs/gopherjs
+go get -u github.com/johanbrandhorst/protobuf/protoc-gen-gopherjs

web_client/main.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	pb "../proto/gopherjs"
+	dom "honnef.co/go/js/dom"
+)
+
+var (
+	document   = dom.GetWindow().Document().(dom.HTMLDocument)
+	serverAddr = "http://raspberrypi.local"
+)
+
+func main() {
+	fmt.Println("Hello")
+
+	client := pb.NewP4WNP1Client(
+		"http://raspberrypi.local:80",
+	)
+	fmt.Printf("Address %v\n", strings.TrimSuffix(document.BaseURI(), "/"))
+	fmt.Printf("Client %v\n", client)
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+
+	gs, err := client.GetDeployedGadgetSetting(ctx, &pb.Empty{})
+	if err == nil {
+		str:=fmt.Sprintf("Gs: %v\n", gs)
+		fmt.Println(str)
+		div_cont:= dom.GetWindow().Document().GetElementByID("content").(*dom.HTMLDivElement)
+		new_div := dom.GetWindow().Document().CreateElement("div").(*dom.HTMLDivElement)
+		new_div.SetTextContent("Result of GetDeployedGadgetSetting gRPC-web call: " + str)
+		div_cont.AppendChild(new_div)
+	} else {
+		fmt.Printf("Error rpc call: %v\n", err)
+	}
+
+}

www/README.md

@@ -0,0 +1,2 @@
+The only file in this directory which isn't auto-generated is index.html.
+

www/index.html

@@ -0,0 +1,11 @@
+<html>
+	<head><title>Hello</title></head>
+<body>
+<script src="webapp.js"></script>
+
+<h1>Testpage for P4wnP1 service</h1>
+<p>See Javascript console for details, entry script is webapp.js (generated by gopherjs)</p>
+
+<div id="content"></div>
+</body>
+</html>