Change to CMD

Dockerfile

@@ -1,3 +1,4 @@
+ARG VERSION=17
 FROM golang AS builder
 
 WORKDIR /app
@@ -9,8 +10,8 @@ COPY ./go.sum /app
 RUN go build -o /app/main /app/src/main.go 
 RUN go build -o /app/cmd /app/src/cmd.go 
 
-ARG JAVA_VERSION=16
+
-FROM openjdk:16
+FROM openjdk:$VERSION
 
 ENV MIN_MEM=512M
 ENV MAX_MEM=1G
@@ -27,4 +28,4 @@ VOLUME [ "/server" ]
 
 WORKDIR /server
 
-ENTRYPOINT [ "/main" ]
+CMD [ "/main" ]

docker-compose.yml

@@ -10,7 +10,7 @@ services:
         MIN_MEM: 1G
         MAX_MEM: 1G
         STOP: stop
-        JAR: jar.jar
+        JAR: server.jar
         REGEX: "Preparing spawn area:"
       ports:
         - 25565:25565

src/main.go

@@ -12,6 +12,7 @@ import (
 	"syscall"
 	"log"
 	"regexp"
+	"bytes"
 
 	"github.com/creack/pty"
 )
@@ -21,6 +22,7 @@ func main() {
 	sigs := make(chan os.Signal, 1)
 	signal.Notify(sigs, syscall.SIGTERM)
 
+	//get environmental variables
 	var minram, maxram, args, stop, jar, regex string
 	for _, e := range os.Environ() {
 		pair := strings.SplitN(e, "=", 2)
@@ -40,17 +42,24 @@ func main() {
 		}
 	}
 
+	//create command
+	var cmdversion *exec.Cmd
+	cmdversion = exec.Command("java", "--version")
+	var out bytes.Buffer
+	cmdversion.Stdout = &out
+	cmdversion.Run()
+	log.Println(out.String())
 
 	log.Printf("Ram: Min: %s Max: %s Stop: %s Jar: %s\n\r", minram, maxram, stop, jar)
 
-	
+	//check if there is a server jar
-
 	if _, err := os.Stat("/server/"+jar); os.IsNotExist(err) {
 		log.Println("\033[31mJar \"" + jar + "\" not found\033[0m")
 		os.Exit(1)
 	}
 	
 	var cmd *exec.Cmd
+	
 	if args == "" {
 		cmd = exec.Command("java", minram, maxram, "-jar", jar)
 	} else {
@@ -58,16 +67,18 @@ func main() {
 		log.Printf("Args: %s \n\r", args)
 	}
 
-
+	//start server
 	cmd.Dir = "/server"
 	tty, err := pty.Start(cmd)
-	ln, _ := net.Listen("tcp", ":8081")
 	
 	if err != nil {
 		panic(err)
 	
 	}
 
+	ln, _ := net.Listen("tcp", ":8081")
+	
+	//cleanup
 	defer func() {
 		cmd.Process.Kill()
 		cmd.Process.Wait()
@@ -84,6 +95,8 @@ func main() {
 		}
 	}()
 
+	//accepts command from cmd.go and sends them to the server
+	
 	go func() {
 		//accept connections from clients
 		for {
@@ -95,7 +108,7 @@ func main() {
 		}
 	}()
 
-	
+	//copy to standard out. If the the is a regex pattern, do output anything that matches
 	go func() {
 		filter := regexp.MustCompile(regex)
 		if(regex != "") {
@@ -106,20 +119,22 @@ func main() {
 					fmt.Println(text)
 				}
 			}
-		} else {
+		} else { //don't filter
 			io.Copy(os.Stdout, tty)
 		}
 	}()
 
+	//copy stdin
 	go func() {
 		io.Copy(tty, os.Stdin)
 	}()
 
-	cmd.Wait()
+	cmd.Wait() //wait for server to stop
 	tty.Write([]byte("\033[31mServer Stopped\033[0m"))
 	os.Exit(0)
 }
 
+//take commands from cmd.go and send it to sdtin of the server
 func handleClient(conn net.Conn, tty *os.File) {
 	defer conn.Close()
 	cmd, _ := bufio.NewReader(conn).ReadString('\n')