Separate out memory statistics and system information into two different services

commands.go

@@ -101,7 +101,7 @@ func runController(c *cli.Context) {
 	if err != nil {
 		Fatalf("Unable to determine current user. Reason: %s\n", err)
 	}
-	if len(c.Args()) <= 2 || c.Args().First() == "help" {
+	if len(c.Args()) < 2 || c.Args().First() == "help" {
 		cli.ShowCommandHelpAndExit(c, "controller", 1) // last argument is exit code
 	}
 	switch c.Args().First() {
@@ -117,7 +117,16 @@ func runController(c *cli.Context) {
 			Fatalln(err)
 		}
 		Println(string(memstats))
+	case "sysinfo":
+		sysinfo, err := controller.GetSysInfo(c.Args().Tail().First())
+		if err != nil {
+			Fatalln(err)
+		}
+		Println(string(sysinfo))
 	case "donut":
+		if len(c.Args()) <= 2 || c.Args().First() == "help" {
+			cli.ShowCommandHelpAndExit(c, "controller", 1) // last argument is exit code
+		}
 		hostname, _ := os.Hostname()
 		err := controller.SetDonut(c.Args().Tail().First(), hostname, c.Args().Tail().Tail())
 		if err != nil {

pkg/controller/client.go

@@ -47,8 +47,30 @@ func GetDisks(url string) ([]string, error) {
 	return reply.Disks, nil
 }
 
-// GetMemStats get system info of the server at given url
+// GetMemStats get memory status of the server at given url
 func GetMemStats(url string) ([]byte, error) {
+	op := RPCOps{
+		Method:  "MemStats.Get",
+		Request: rpc.Args{Request: ""},
+	}
+	req, err := NewRequest(url, op, http.DefaultTransport)
+	if err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	resp, err := req.Do()
+	if err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	defer resp.Body.Close()
+	var reply rpc.MemStatsReply
+	if err := jsonrpc.DecodeClientResponse(resp.Body, &reply); err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	return json.MarshalIndent(reply, "", "\t")
+}
+
+// GetSysInfo get system status of the server at given url
+func GetSysInfo(url string) ([]byte, error) {
 	op := RPCOps{
 		Method:  "SysInfo.Get",
 		Request: rpc.Args{Request: ""},
@@ -96,4 +118,4 @@ func SetDonut(url, hostname string, disks []string) error {
 	return reply.Error
 }
 
-// Add more functions here for many replies
+// Add more functions here for other RPC messages

pkg/server/router.go

@@ -114,8 +114,9 @@ func getRPCHandler() http.Handler {
 	s.RegisterJSONCodec()
 	s.RegisterService(new(rpc.VersionService), "Version")
 	s.RegisterService(new(rpc.SysInfoService), "SysInfo")
+	s.RegisterService(new(rpc.MemStatsService), "MemStats")
 	s.RegisterService(new(rpc.DiskInfoService), "DiskInfo")
 	s.RegisterService(new(rpc.DonutService), "Donut")
-	// Add new services here
+	// Add new RPC services here
 	return registerRPC(router.NewRouter(), s)
 }

pkg/server/rpc/sysinfo.go

@@ -29,13 +29,20 @@ type SysInfoService struct{}
 
 // SysInfoReply -
 type SysInfoReply struct {
-	Hostname  string           `json:"hostname"`
-	SysARCH   string           `json:"sys.arch"`
-	SysOS     string           `json:"sys.os"`
-	SysCPUS   int              `json:"sys.ncpus"`
-	Routines  int              `json:"goroutines"`
-	GOVersion string           `json:"goversion"`
-	MemStats  runtime.MemStats `json:"memstats"`
+	Hostname  string `json:"hostname"`
+	SysARCH   string `json:"sys.arch"`
+	SysOS     string `json:"sys.os"`
+	SysCPUS   int    `json:"sys.ncpus"`
+	Routines  int    `json:"goroutines"`
+	GOVersion string `json:"goversion"`
+}
+
+// MemStatsService -
+type MemStatsService struct{}
+
+// MemStatsReply -
+type MemStatsReply struct {
+	runtime.MemStats `json:"memstats"`
 }
 
 func setSysInfoReply(sis *SysInfoReply) error {
@@ -50,11 +57,13 @@ func setSysInfoReply(sis *SysInfoReply) error {
 	if err != nil {
 		return iodine.New(err, nil)
 	}
+	return nil
+}
 
+func setMemStatsReply(sis *MemStatsReply) error {
 	var memStats runtime.MemStats
 	runtime.ReadMemStats(&memStats)
 	sis.MemStats = memStats
-
 	return nil
 }
 
@@ -62,3 +71,8 @@ func setSysInfoReply(sis *SysInfoReply) error {
 func (s *SysInfoService) Get(r *http.Request, args *Args, reply *SysInfoReply) error {
 	return setSysInfoReply(reply)
 }
+
+// Get method
+func (s *MemStatsService) Get(r *http.Request, args *Args, reply *MemStatsReply) error {
+	return setMemStatsReply(reply)
+}