Initial work at making the server proper.

README.md

@@ -78,3 +78,24 @@ Both the manager and the agent will have similar setups:
 * All reads go to a `readProcessor()` which in turn parses the message, and in turn does the appropriate logic (read, calling go routine/functions)
 
 This does however presents me with a problem. Since all communication is reactive, state-less, and all over the same connection; so tracking things is a bit hard. And this is something for maybe the next phase. So for now, reactive content only. This said, I need figure out how on earth I can prevent an agent from taking two jobs at the same time. I guess I will need to build in some agent state tracking for this.
+
+#### Server setup
+_(This piece assumes that the network is super fast, and turbo stable.)_
+
+The current setup of the server is only the thing that its connected to. There is a writer that spams something, a reader that prints everything it receives to the console. And that is it. Pretty much split-brain and it currently lacks the ability to manage workloads on agents.
+
+For this exercise it needs to be able to handle multiple agents, but start at one. There needs to be an interface that should tell me how much CPU/MEMs an agent has. And finally tell the agent to solve something and accept any answers it returns.
+
+Another issue is that it needs a manager interfaces to keep track of Agents, agents metrics, status. But also allow users to issue commands. NFC how I am going to do that. But something tells me it will require me to find a way to communicate all this with the user, and I can do this with a simple REST API, or create a terminal interface, or do web things.
+
+
+1. Incoming connection gets caught by `handleConnections()`
+2. `handleConnections()` verifies an agent registers
+3. After registeration it puts this into a map, along with the `conn` and stuffs this into a slice of maps
+4. The manager pics up the new agent, and offers info to anyone who wants to see it.
+5. A client can ask the manager to solve a puzzle, manager calculates which agents to use, sends of the work.
+6. Solution is returned and stored.
+
+So from there.
+
+I think the biggest issue now is find a way to have a terminal or web interface with the user.

main.go

@@ -26,7 +26,7 @@ func main() {
 	// Switch on the role
 	switch vars.Role {
 	case "scheduler":
-		server := server.Server{ListenAddress: vars.Address, ListenPort: vars.Port}
+		server := server.Server{ListenAddress: vars.Address, ListenPort: vars.Port, Agents: make(map[string]*server.Agent)}
 		vars.Operator = &server
 	case "agent":
 		client := client.Client{ServerAddress: vars.Address, ServerPort: vars.Port}

server/Start.go

@@ -4,63 +4,17 @@ import (
 	"log"
 	"net/http"
 	"strconv"
-	"time"
-
-	"github.com/gorilla/websocket"
 )
 
+// Start the HTTP and WebSocket server
 func (server *Server) Start() {
-	// Start the server
-	http.HandleFunc("/ws", func(w http.ResponseWriter, r *http.Request) {
-		handleConnections(w, r)
-	})
+	// Declare ourselves up and running to the console.
+	log.Println("Started sudoku-funpark server")
+
+	// Start the http server
+	http.HandleFunc("/json", server.jsonDumper)
+
+	// Start the websocket server
+	http.HandleFunc("/ws", server.handleConnections)
 	log.Fatal(http.ListenAndServe(server.ListenAddress+":"+strconv.Itoa(server.ListenPort), nil))
-
-	// return nil
-}
-
-var upgrader = websocket.Upgrader{
-	ReadBufferSize:  1024,
-	WriteBufferSize: 1024,
-}
-
-func handleConnections(w http.ResponseWriter, r *http.Request) {
-	conn, err := upgrader.Upgrade(w, r, nil)
-	if err != nil {
-		log.Println(err)
-		return
-	}
-	defer conn.Close()
-
-	log.Println("Starting server")
-	go readMessages(conn)
-	writeMessages(conn)
-
-}
-
-func readMessages(conn *websocket.Conn) {
-	for {
-		messageType, message, err := conn.ReadMessage()
-		if err != nil {
-			log.Println("Error reading message:", err)
-			break
-		}
-		log.Printf("Received(%d): %s\n", messageType, message)
-
-		// This sets the time-out for any incoming messages.
-		// conn.SetReadDeadline(time.Now().Add(10 * time.Second))
-	}
-}
-
-func writeMessages(conn *websocket.Conn) {
-	for {
-		err := conn.WriteMessage(websocket.TextMessage, []byte("keep alive - staying alive"))
-		if err != nil {
-			log.Println("Error writing message:", err)
-			break
-		}
-		// This sets the time-out for any outgoing messages.
-		// conn.SetWriteDeadline(time.Now().Add(10 * time.Second))
-		time.Sleep(time.Minute)
-	}
 }

server/closeConnection.go

@@ -0,0 +1,6 @@
+package server
+
+func (server *Server) closeConnection(agentName string) {
+	server.Agents[agentName].conn.Close()
+	delete(server.Agents, agentName)
+}

server/handleConnections.go

@@ -0,0 +1,66 @@
+package server
+
+import (
+	"log"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Handle incoming websocket connections
+func (server *Server) handleConnections(w http.ResponseWriter, r *http.Request) {
+	conn, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		log.Println(err)
+		return
+	}
+	// defer conn.Close()
+
+	log.Println("Incoming connection")
+
+	// Check for register
+	var registered bool
+	var msgs []string
+	for !registered {
+		_, message, err := conn.ReadMessage()
+		if err != nil {
+			log.Println("Error reading message:", err)
+			break
+		}
+
+		msgs = server.parseMessage(message)
+		if string(msgs[0]) == "register" {
+			registered = true
+		}
+	}
+	log.Println("Connected to agent")
+
+	// Create var of type Agent
+	cores_int, err := strconv.Atoi(msgs[2])
+	if err != nil {
+		log.Fatal("ERROR: failed strconv.Atoi(cpu cores):", err)
+	}
+	mem_max_string := strings.ReplaceAll(msgs[3], "GB", "")
+	mem_max_float, err := strconv.ParseFloat(mem_max_string, 64)
+	if err != nil {
+		log.Fatal("ERROR: failed strconv.ParseFloat():", err)
+	}
+	agent := Agent{
+		Name:    msgs[1],
+		Reg:     time.Now(),
+		Cores:   cores_int,
+		Mem_max: mem_max_float,
+		TaskId:  0,
+		conn:    conn,
+	}
+
+	// Dump it into server.Agents
+	server.Agents[msgs[1]] = &agent
+
+	defer server.closeConnection(msgs[1])
+
+	go server.readMessages(agent)
+	server.writeMessages(conn)
+
+}

server/jsonDumper.go

@@ -0,0 +1,19 @@
+package server
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+func (server *Server) jsonDumper(w http.ResponseWriter, r *http.Request) {
+	json, err := json.Marshal(server)
+	if err != nil {
+		fmt.Println("JSON Marshaling error:", err)
+		w.WriteHeader(http.StatusInternalServerError)
+		w.Write([]byte("This is my Website"))
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	w.Write(json)
+}

server/parseMessage.go

@@ -0,0 +1,7 @@
+package server
+
+import "strings"
+
+func (server *Server) parseMessage(message []byte) []string {
+	return strings.Split(string(message), ";")
+}

server/pruneSlice.go

@@ -0,0 +1,29 @@
+package server
+
+import "slices"
+
+func (server *Server) pruneIntSlice(mySlice []int) []int {
+	if len(mySlice) > 10 {
+		for key := range mySlice {
+			if key == 10 {
+				mySlice = slices.Delete(mySlice, 9, 10)
+			} else {
+				mySlice[key] = mySlice[key+1]
+			}
+		}
+	}
+	return mySlice
+}
+
+func (server *Server) pruneFloat64Slice(mySlice []float64) []float64 {
+	if len(mySlice) > 10 {
+		for key := range mySlice {
+			if key == 10 {
+				mySlice = slices.Delete(mySlice, 9, 10)
+			} else {
+				mySlice[key] = mySlice[key+1]
+			}
+		}
+	}
+	return mySlice
+}

server/readMessages.go

@@ -0,0 +1,52 @@
+package server
+
+import (
+	"fmt"
+	"log"
+	"strconv"
+	"strings"
+)
+
+// Rewrite to become a general input handler
+func (server *Server) readMessages(agent Agent) {
+	for {
+		_, message, err := agent.conn.ReadMessage()
+		if err != nil {
+			log.Println("Error reading message:", err)
+			break
+		}
+		// log.Printf("Received(%d): %s\n", messageType, message)
+
+		msgs := server.parseMessage(message)
+
+		if msgs[0] == "update" {
+			cpu_usg, err := strconv.Atoi(msgs[1])
+			if err != nil {
+				fmt.Println("ERROR: converting string to int", err)
+			}
+			server.Agents[agent.Name].Cpu = append(server.Agents[agent.Name].Cpu, cpu_usg)
+			server.Agents[agent.Name].Cpu = server.pruneIntSlice(server.Agents[agent.Name].Cpu)
+
+			mem_usg_string := strings.ReplaceAll(msgs[2], "GB", "")
+			mem_usg_float, err := strconv.ParseFloat(mem_usg_string, 64)
+			if err != nil {
+				log.Fatal("ERROR: failed strconv.ParseFloat():", err)
+			}
+			server.Agents[agent.Name].Mem_usg = append(server.Agents[agent.Name].Mem_usg, mem_usg_float)
+			server.Agents[agent.Name].Mem_usg = server.pruneFloat64Slice(server.Agents[agent.Name].Mem_usg)
+
+			taskId, err := strconv.Atoi(msgs[3])
+			if err != nil {
+				log.Println("ERROR: cannot convert taskId:", err)
+			}
+			server.Agents[agent.Name].TaskId = taskId
+		}
+
+		if msgs[0] == "deregister" {
+			server.closeConnection(agent.Name)
+		}
+
+		// This sets the time-out for any incoming messages.
+		// conn.SetReadDeadline(time.Now().Add(10 * time.Second))
+	}
+}

server/types.go

@@ -1,6 +1,35 @@
 package server
 
+import (
+	"time"
+
+	"github.com/gorilla/websocket"
+)
+
+type Agent struct {
+	Name    string
+	Reg     time.Time
+	Cores   int
+	Cpu     []int
+	Mem_max float64
+	Mem_usg []float64
+	TaskId  int
+	conn    *websocket.Conn
+}
+
+type Task struct {
+	Puzzle    [9]string
+	Solutions [][]string
+}
+
 type Server struct {
 	ListenAddress string
 	ListenPort    int
+	Agents        map[string]*Agent
+	Tasks         []Task
+}
+
+var upgrader = websocket.Upgrader{
+	ReadBufferSize:  1024,
+	WriteBufferSize: 1024,
 }

server/writeMessages.go

@@ -0,0 +1,19 @@
+package server
+
+import (
+	"log"
+
+	"github.com/gorilla/websocket"
+)
+
+func (server *Server) writeMessages(conn *websocket.Conn) {
+	for {
+		err := conn.WriteMessage(websocket.TextMessage, []byte("keep alive - staying alive"))
+		if err != nil {
+			log.Println("Error writing message:", err)
+			break
+		}
+		// This sets the time-out for any outgoing messages.
+		// conn.SetWriteDeadline(time.Now().Add(10 * time.Second))
+	}
+}