homelab-frontend/cmd/gateway/main.go

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"

	"forgejo.riotpiao.com/rock/homelab-frontend/internal/auth"
	"forgejo.riotpiao.com/rock/homelab-frontend/internal/config"
	"forgejo.riotpiao.com/rock/homelab-frontend/internal/proxy"
	"forgejo.riotpiao.com/rock/homelab-frontend/internal/server"
	"forgejo.riotpiao.com/rock/homelab-frontend/internal/serviceadapter"
	"forgejo.riotpiao.com/rock/homelab-frontend/internal/temporal"
	"forgejo.riotpiao.com/rock/homelab-frontend/internal/tracing"
)

func main() {
	ctx := context.Background()

	// Initialize OpenTelemetry tracing
	tracingCfg := tracing.DefaultConfig()
	shutdownTracer, err := tracing.Init(ctx, tracingCfg)
	if err != nil {
		log.Printf("warning: failed to initialize tracing: %v", err)
	} else {
		log.Printf("tracing initialized: service=%s endpoint=%s", tracingCfg.ServiceName, tracingCfg.OTLPEndpoint)
		defer func() {
			if err := shutdownTracer(ctx); err != nil {
				log.Printf("error shutting down tracer: %v", err)
			}
		}()
	}

	// Load configuration
	cfg, err := config.Load()
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to load config: %v\n", err)
		os.Exit(1)
	}

	// Determine if auth is enabled by checking if any route requires it
	authEnabled := false
	for _, route := range cfg.Routes {
		if route.Upstream.AuthRequired {
			authEnabled = true
			break
		}
	}

	// Create the reverse proxy handler that routes requests based on configuration
	upstreamHandler := proxy.New(cfg)

	// Create the Temporal workflow handler
	// Temporal server address can be configured via environment variable
	temporalHostPort := os.Getenv("TEMPORAL_HOST_PORT")
	if temporalHostPort == "" {
		temporalHostPort = "localhost:7233"
	}
	log.Printf("Temporal server: %s", temporalHostPort)
	temporalHandler := temporal.NewHandler(temporalHostPort)

	// Create server with health checker
	srv := server.New(cfg.ListenAddr, cfg.ShutdownTimeout, nil)
	
	// Initialize health checker with config validity and auth status
	healthChecker := server.NewHealthChecker(true, authEnabled)
	srv.SetHealthChecker(healthChecker)
	
	// Create ServiceAdapter registry and dispatcher (phase 8)
	registry := serviceadapter.NewRegistry(nil)
	
	// Add workflow service adapter (uses Temporal handler for gRPC forwarding)
	workflowSpec := serviceadapter.GetWorkflowSpec()
	workflowAdapter := &serviceadapter.ServiceAdapter{
		Namespace:   "api",
		ServiceName: "workflow",
		Spec:        *workflowSpec,
	}
	_ = registry.Add(workflowAdapter)
	
	// Add other adapters from config
	for _, a := range cfg.Adapters {
		_ = registry.Add(a)
	}
	log.Printf("%d service adapters loaded", registry.Count())

	// Create shared JWT validator for X-Service auth enforcement
	var jwtValidator *auth.Validator
	if cfg.Auth.Enabled && cfg.Auth.JWKSURL != "" {
		jwtValidator = auth.NewValidator(cfg.Auth.Issuer, cfg.Auth.Audience, cfg.Auth.JWKSURL)
	}
	dispatcher := serviceadapter.NewDispatcher(registry, jwtValidator)
	
	// Wire workflow adapter to temporal handler for proper request forwarding
	workflowAdapterImpl := serviceadapter.NewWorkflowAdapter(temporalHandler)
	_ = workflowAdapterImpl // The dispatcher will call temporal handler directly for gRPC

	// Create router that handles health endpoints, X-Service (ServiceAdapter) routing,
	// temporal endpoints, and passes others to upstream handler
	router := server.NewRouter(healthChecker, dispatcher, temporalHandler, upstreamHandler)

	// Wrap router with tracing middleware
	tracedRouter := tracing.Middleware(router)
	srv.SetHandler(tracedRouter)

	// Set up signal handling
	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan, syscall.SIGTERM, syscall.SIGINT)

	// Start server in a goroutine
	var serverErr error
	go func() {
		log.Printf("gateway listening on %s", srv.Addr())
		serverErr = srv.ListenAndServe()
		if serverErr != nil && serverErr != http.ErrServerClosed {
			log.Printf("server error: %v", serverErr)
		}
	}()

	// Wait for shutdown signal
	sig := <-sigChan
	log.Printf("received signal: %v", sig)

	// Gracefully shutdown the server
	if err := srv.Shutdown(context.Background()); err != nil {
		fmt.Fprintf(os.Stderr, "shutdown error: %v\n", err)
		os.Exit(1)
	}

	log.Printf("gateway shutdown complete")
	os.Exit(0)
}