ModelRouter/cmd/modelrouter/main.go

// Command modelrouter is a standalone gateway that exposes multiple upstream LLM
// sources behind a unified OpenAI-compatible HTTP API. Protocol differences are
// handled by Lua adapters (per source), optionally signing outgoing requests.
// It supports explicit model selection or AUTO routing by priority, image
// generation, multimodal payloads, a web UI for adapter/source management, and
// concurrent/queued scheduling with backoff and failover.
package main

import (
	"flag"
	"log"
	"net/http"
	"os"
	"os/signal"
	"strings"
	"syscall"
	"time"

	"modelrouter/internal/config"
	"modelrouter/internal/core"
	"modelrouter/internal/gateway"
)

func main() {
	cfgPath := flag.String("config", "config.yaml", "path to gateway config file")
	checkOnly := flag.Bool("check", false, "validate the config file and exit (0 = valid, 1 = invalid); nothing is started and no file is written")
	showSecrets := flag.Bool("show-secrets", false, "print the config's credentials in the clear and exit; nothing is started and no file is written")
	flag.Parse()

	// -check is the deploy-time preflight: parse and validate the config
	// without starting the Lua VM, touching runtime.json, or binding a port.
	// It deliberately does NOT call EnsureDefault, so a missing file is an
	// error here instead of being silently created.
	if *checkOnly {
		if _, err := os.Stat(*cfgPath); err != nil {
			log.Fatalf("[modelrouter] check: %v", err)
		}
		if _, err := config.Load(*cfgPath); err != nil {
			log.Fatalf("[modelrouter] check: %v", err)
		}
		log.Printf("[modelrouter] check: %s is valid", *cfgPath)
		return
	}

	// -show-secrets is the operator escape hatch for a config whose
	// credentials are sealed at rest: it prints them to stdout and exits
	// without starting anything or writing anything. Nothing else in the
	// program prints a credential, and this path never logs to a file.
	if *showSecrets {
		if _, err := os.Stat(*cfgPath); err != nil {
			log.Fatalf("[modelrouter] show-secrets: %v", err)
		}
		if err := config.PrintSecrets(*cfgPath); err != nil {
			log.Fatalf("[modelrouter] show-secrets: %v", err)
		}
		return
	}

	created, err := config.EnsureDefault(*cfgPath)
	if err != nil {
		log.Fatalf("[modelrouter] config: %v", err)
	}

	c, err := core.New(*cfgPath)
	if err != nil {
		log.Fatalf("[modelrouter] core: %v", err)
	}
	defer c.Close()

	if created {
		for _, k := range c.GatewayKeys() {
			log.Printf("[modelrouter] generated default config at %s — admin key: %s (rotate it in the WebUI after first login)", *cfgPath, k)
		}
	}

	gw, err := gateway.New(c)
	if err != nil {
		log.Fatalf("[modelrouter] gateway: %v", err)
	}

	// Ops hygiene: surface the two most common footguns instead of silently
	// running with them.
	//
	// Read the AUTHORITATIVE source. Auth uses core.ListKeys() (cfg.Keys), not
	// the legacy cfg.GatewayKeys list: seedKeys copies gateway_keys into keys[]
	// on first start and the YAML list is ignored for auth afterwards. Checking
	// GatewayKeys() here made the warning lie — once the legacy list was empty
	// (e.g. after rotating the starter key away) it reported "every request is
	// rejected" while seven working keys, one of them admin, were in service.
	if keys := c.ListKeys(); len(keys) == 0 {
		log.Printf("[modelrouter] WARNING: no gateway key configured — every request will be rejected. Add one in the WebUI or set gateway_keys")
	} else {
		for _, k := range keys {
			if k.Key == "sk-gw-local-0001" || k.Key == "sk-local-0001" {
				log.Printf("[modelrouter] WARNING: gateway key %q looks like the starter/example key — rotate it before exposing the gateway", k.Key)
			}
		}
	}
	if l := c.Listen(); strings.HasPrefix(l, "0.0.0.0:") || strings.HasPrefix(l, "::") {
		log.Printf("[modelrouter] WARNING: listen=%s binds ALL interfaces — bind an internal address in production", l)
	}

	srv := &http.Server{
		Addr:              c.Listen(),
		Handler:           gw.Handler(),
		ReadHeaderTimeout: 10 * time.Second,
	}
	go func() {
		cert, key := c.TLS()
		if cert != "" && key != "" {
			log.Printf("[modelrouter] listening HTTPS on %s (cert=%q) (default_model=%s, models=%v, adapters=%d)",
				c.Listen(), cert, c.DefaultModel(), c.Registry().ModelList(), len(c.ListAdapters()))
			if err := srv.ListenAndServeTLS(cert, key); err != nil && err != http.ErrServerClosed {
				log.Fatalf("[modelrouter] server: %v", err)
			}
			return
		}
		log.Printf("[modelrouter] listening HTTP on %s (default_model=%s, models=%v, adapters=%d)",
			c.Listen(), c.DefaultModel(), c.Registry().ModelList(), len(c.ListAdapters()))
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("[modelrouter] server: %v", err)
		}
	}()

	stop := make(chan os.Signal, 1)
	signal.Notify(stop, syscall.SIGINT, syscall.SIGTERM)
	<-stop
	log.Printf("[modelrouter] shutting down")
}