Working communication code using socket

Sockets are sooo much better, waow
I like easy code

Closes #11 (even if I didn't implement all the proposal)
Closes #16

app/cli.go

@@ -2,13 +2,10 @@ package app
 
 import (
 	"encoding/gob"
-	"errors"
 	"fmt"
 	"log"
-	"math/rand"
+	"net"
 	"os"
-	"path"
-	"time"
 )
 
 const (
@@ -18,7 +15,6 @@ const (
 
 type Request struct {
 	Request int
-	Id      int
 	Pattern string
 }
 
@@ -27,65 +23,27 @@ type Response struct {
 	Actions ReadableMap
 }
 
-// Runtime files:
+func SocketPath() string {
-// /run/user/<uid>/reaction/reaction.pipe
+	return fmt.Sprintf("/run/user/%v/reaction.sock", os.Getuid())
-// /run/user/<uid>/reaction/id.response
-
-func RuntimeDirectory() string {
-	return fmt.Sprintf("/run/user/%v/reaction/", os.Getuid())
-}
-
-func PipePath() string {
-	return path.Join(RuntimeDirectory(), "reaction.pipe")
-}
-
-func (r Request) ResponsePath() string {
-	return path.Join(RuntimeDirectory(), string(r.Id))
-}
-
-func Send(data Request) {
-	pipePath := PipePath()
-	pipe, err := os.OpenFile(pipePath, os.O_RDWR, os.ModeNamedPipe)
-	if err != nil {
-		log.Println("Failed to open", pipePath, ":", err)
-		log.Fatalln("Is the reaction daemon running? Does the CLI run as the same user?")
-	}
-	log.Println("DEBUG opening ok, encoding...")
-	enc := gob.NewEncoder(pipe)
-	err = enc.Encode(data)
-	if err != nil {
-		log.Fatalf("Failed to write to %s: %s", pipePath, err)
-	}
 }
 
 func SendAndRetrieve(data Request) Response {
-	if data.Id == 0 {
+	conn, err := net.Dial("unix", SocketPath())
-		data.Id = rand.Int()
-	}
-	log.Println("DEBUG sending:", data)
-	Send(data)
-	responsePath := data.ResponsePath()
-	d, _ := time.ParseDuration("100ms")
-	for tries := 20; tries > 0; tries-- {
-		log.Println("DEBUG waiting for answer...")
-		file, err := os.Open(responsePath)
-		if errors.Is(err, os.ErrNotExist) {
-			time.Sleep(d)
-			continue
-		}
-		defer os.Remove(responsePath)
 	if err != nil {
-			log.Fatalf("Error opening daemon answer: %s", err)
+		log.Fatalln("Error opening connection top daemon:", err)
 	}
+
+	err = gob.NewEncoder(conn).Encode(data)
+	if err != nil {
+		log.Fatalln("Can't send message:", err)
+	}
+
 	var response Response
-		err = gob.NewDecoder(file).Decode(&response)
+	err = gob.NewDecoder(conn).Decode(&response)
 	if err != nil {
-			log.Fatalf("Error parsing daemon answer: %s", err)
+		log.Fatalln("Invalid answer from daemon:", err)
 	}
 	return response
-	}
-	log.Fatalln("Timeout while waiting answer from the daemon")
-	return Response{errors.New("unreachable code"), nil}
 }
 
 func usage(err string) {
@@ -96,7 +54,7 @@ func usage(err string) {
 
 func CLI() {
 	if len(os.Args) <= 1 {
-		response := SendAndRetrieve(Request{Query, 0, ""})
+		response := SendAndRetrieve(Request{Query, ""})
 		if response.Err != nil {
 			log.Fatalln("Received error from daemon:", response.Err)
 		}
@@ -108,7 +66,7 @@ func CLI() {
 		if len(os.Args) != 3 {
 			usage("flush takes one <PATTERN> argument")
 		}
-		response := SendAndRetrieve(Request{Flush, 0, os.Args[2]})
+		response := SendAndRetrieve(Request{Flush, os.Args[2]})
 		if response.Err != nil {
 			log.Fatalln("Received error from daemon:", response.Err)
 		}

app/pipe.go

@@ -2,12 +2,10 @@ package app
 
 import (
 	"encoding/gob"
-	"errors"
 	"log"
+	"net"
 	"os"
 	"sync"
-	"syscall"
-	"time"
 
 	"gopkg.in/yaml.v3"
 )
@@ -109,78 +107,60 @@ func (r ReadableMap) ToString() string {
 	return string(text)
 }
 
-// Pipe-related, server-related functions
+// Socket-related, server-related functions
 
-func createOpenPipe() *os.File {
+func createOpenSocket() net.Listener {
-	err := os.Mkdir(RuntimeDirectory(), 0755)
+	socketPath := SocketPath()
-	if err != nil && !errors.Is(err, os.ErrExist) {
+	_, err := os.Stat(socketPath)
-		log.Fatalln("FATAL Failed to create runtime directory", err)
-	}
-	pipePath := PipePath()
-	_, err = os.Stat(pipePath)
 	if err == nil {
-		log.Println("WARN  Runtime file", pipePath, "already exists: Is the daemon already running? Deleting.")
+		log.Println("WARN  socket", socketPath, "already exists: Is the daemon already running? Deleting.")
-		err = os.Remove(pipePath)
+		err = os.Remove(socketPath)
 		if err != nil {
-			log.Println("FATAL Failed to remove runtime file:", err)
+			log.Println("FATAL Failed to remove socket:", err)
 		}
 	}
-	err = syscall.Mkfifo(pipePath, 0600)
+	ln, err := net.Listen("unix", socketPath)
 	if err != nil {
-		log.Println("FATAL Failed to create runtime file:", err)
+		log.Println("FATAL Failed to create socket:", err)
-	}
-	file, err := os.OpenFile(pipePath, os.O_RDONLY, os.ModeNamedPipe)
-	if err != nil {
-		log.Println("FATAL Failed to open runtime file:", err)
-	}
-	return file
-}
-
-func Respond(request Request, response Response) {
-	file, err := os.Create(request.ResponsePath())
-	if err != nil {
-		log.Println("WARN  Can't respond to message:", err)
-		return
-	}
-	err = gob.NewEncoder(file).Encode(response)
-	if err != nil {
-		log.Println("WARN  Can't respond to message:", err)
-		return
 	}
+	return ln
 }
 
 // Handle connections
 func Serve() {
-	pipe := createOpenPipe()
+	ln := createOpenSocket()
+	defer ln.Close()
 	for {
+		conn, err := ln.Accept()
+		if err != nil {
+			log.Println("ERROR Failed to open connection from cli:", err)
+			continue
+		}
+		go func(conn net.Conn) {
 			var request Request
-		err := gob.NewDecoder(pipe).Decode(&request)
-		if err != nil {
-			d, _ := time.ParseDuration("1s")
-			if err.Error() == "EOF" {
-				log.Println("DEBUG received EOF, seeking one byte")
-				_, err = pipe.Seek(1, 1)
-				if err != nil {
-					log.Println("DEBUG failed to seek:", err)
-				}
-				time.Sleep(d)
-				continue
-			}
-			log.Println("WARN  Invalid Message received:", err)
-			time.Sleep(d)
-			continue
-		}
-		go func(request Request) {
 			var response Response
+
+			err := gob.NewDecoder(conn).Decode(&request)
+			if err != nil {
+				log.Println("ERROR Invalid Message from cli:", err)
+				return
+			}
+
 			switch request.Request {
 			case Query:
 				response.Actions = actionStore.store.ToReadable()
 			case Flush:
 				actionStore.Flush(request.Pattern)
 			default:
-				log.Println("WARN  Invalid Message: unrecognised Request type")
+				log.Println("ERROR Invalid Message from cli: unrecognised Request type")
+				return
 			}
-			Respond(request, response)
+
-		}(request)
+			gob.NewEncoder(conn).Encode(response)
+			if err != nil {
+				log.Println("ERROR Can't respond to cli:", err)
+				return
+			}
+		}(conn)
 	}
 }

app/reaction.go

@@ -24,10 +24,10 @@ func cmdStdout(commandline []string) chan *string {
 		cmd := exec.Command(commandline[0], commandline[1:]...)
 		stdout, err := cmd.StdoutPipe()
 		if err != nil {
-			log.Fatalln("couldn't open stdout on command:", err)
+			log.Fatalln("FATAL couldn't open stdout on command:", err)
 		}
 		if err := cmd.Start(); err != nil {
-			log.Fatalln("couldn't start command:", err)
+			log.Fatalln("FATAL couldn't start command:", err)
 		}
 		defer stdout.Close()
 
@@ -221,7 +221,7 @@ func Main() {
 				quit()
 			}
 		case <-sigs:
-			log.Printf("Received SIGINT or SIGTERM, exiting")
+			log.Printf("INFO  Received SIGINT/SIGTERM, exiting")
 			quit()
 		}
 	}
@@ -235,7 +235,7 @@ func quit() {
 	// wait for them to complete
 	wgActions.Wait()
 	// delete pipe
-	os.Remove(PipePath())
+	os.Remove(SocketPath())
 
 	os.Exit(3)
 }