feat: Add health check endpoint

README.md

@@ -110,6 +110,10 @@ export N8N_RUNNERS_AUTH_TOKEN=...
 make run
 ```
 
+## Health check
+
+The launcher exposes a health check endpoint at `/healthz` on port `5681` for liveness checks.
+
 ## Release
 
 1. Create a git tag following semver:

cmd/launcher/main.go

@@ -2,9 +2,11 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"os"
 
 	"task-runner-launcher/internal/commands"
+	"task-runner-launcher/internal/http"
 	"task-runner-launcher/internal/logs"
 )
 
@@ -20,6 +22,15 @@ func main() {
 		os.Exit(1)
 	}
 
+	srv := http.NewHealthCheckServer()
+	go func() {
+		if err := srv.Start(); err != nil {
+			fmt.Printf("Health check server failed to start: %s", err)
+			os.Exit(1)
+		}
+	}()
+	logs.Logger.Printf("Started healthcheck server on port %d", srv.Port)
+
 	runnerType := os.Args[1]
 	cmd := &commands.LaunchCommand{RunnerType: runnerType}
 

internal/http/healthcheck_server.go

@@ -0,0 +1,47 @@
+package http
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+const (
+	defaultPort     = 5681
+	healthCheckPath = "/healthz"
+)
+
+type healthCheckResponse struct {
+	Status string `json:"status"`
+}
+
+type Server struct {
+	Port int
+}
+
+func NewHealthCheckServer() *Server {
+	return &Server{
+		Port: defaultPort,
+	}
+}
+
+func (s *Server) Start() error {
+	http.HandleFunc(healthCheckPath, s.handleHealthCheck)
+
+	addr := fmt.Sprintf(":%d", s.Port)
+
+	return http.ListenAndServe(addr, nil)
+}
+
+func (s *Server) handleHealthCheck(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+
+	res := healthCheckResponse{Status: "ok"}
+	json.NewEncoder(w).Encode(res)
+}