Improve logging and error handling

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Author: alexellis

Dockerfile

@@ -1,4 +1,4 @@
-FROM --platform=${BUILDPLATFORM:-linux/amd64} golang:1.23 as build
+FROM --platform=${BUILDPLATFORM:-linux/amd64} golang:1.25 as build
 
 ARG TARGETPLATFORM
 ARG BUILDPLATFORM

go.mod

@@ -1,6 +1,6 @@
 module slicer-ssh-agent
 
-go 1.23.4
+go 1.25
 
 require (
 	github.com/creack/pty v1.1.24

main.go

@@ -32,6 +32,7 @@ Copyright (c) 2025 Alex Ellis, OpenFaaS Ltd
 `, Version)
 
 	port := uint32(514)
+
 	l, err := vsock.Listen(port, nil)
 	if err != nil {
 		log.Fatal(err)
@@ -41,10 +42,11 @@ Copyright (c) 2025 Alex Ellis, OpenFaaS Ltd
 	for {
 		conn, err := l.Accept()
 		if err != nil {
-			log.Fatal(err)
+			log.Printf("Error accepting connection: %v", err)
+			continue
 		}
 
-		fmt.Printf("Connection accepted from socket\n")
+		fmt.Printf("Connection from socket. CID: %d\n", conn.RemoteAddr().(*vsock.Addr).ContextID)
 
 		go handleConnection(conn)
 	}
@@ -53,6 +55,11 @@ Copyright (c) 2025 Alex Ellis, OpenFaaS Ltd
 func handleConnection(conn net.Conn) {
 	defer conn.Close()
 
+	if conn.RemoteAddr().(*vsock.Addr).ContextID != vsock.Host {
+		log.Printf("Closing connection from CID: %d, not allowed.", conn.RemoteAddr().(*vsock.Addr).ContextID)
+		return
+	}
+
 	var err error
 	// Try multiple shells in order of preference
 	shells := []string{"/bin/bash", "/bin/sh", "/usr/bin/sh"}