Standalone & embedded

Run switchboard serve as a single-binary proxy, or embed the engine as middleware in any Go HTTP server.

Caddy is the reference adapter, but the engine doesn’t require it.

switchboard serve

A single binary that reverse-proxies to one upstream with live rule reloads. It’s ideal for local development, tests, and single-machine deployments:

switchboard serve \
  --listen :8080 \
  --upstream localhost:3000 \
  --registry file://./registry \
  --channel dev

It runs the same engine and reconciler as the Caddy module, and honors --fail-mode (open, closed, last_good) and --cache-dir for durable last-known-good.

Built-in endpoints:

• GET /switchboard/status: reconciler and pool state as JSON.
• GET /metrics: Prometheus metrics.

All flags are in the CLI reference.

Embedding in a Go server

The same engine mounts as net/http middleware:

package main

import (
	"context"
	"net/http"

	httpadapter "github.com/ethndotsh/switchboard/adapters/http"
	"github.com/ethndotsh/switchboard/engine"
)

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

	service, err := engine.Start(ctx, engine.Config{
		RegistryURL: "file://./registry",
		Channel:     "dev",
	}, logger)
	if err != nil {
		panic(err)
	}
	defer service.Close(ctx)

	handler := httpadapter.Middleware(service, httpadapter.Options{
		FailMode: "open",
		Logger:   logger,
	})

	server := &http.Server{
		Addr:    ":8080",
		Handler: handler(application),
	}
	server.ListenAndServe()
}

engine.Config accepts the same knobs as the Caddy directives: Namespace, PollInterval, InvokeTimeout, MemoryLimit, CacheDir, FailMode, pool sizing, and the rest. See the Caddyfile reference for meanings and defaults; the Go field names match.

service.Status() returns the same structure as the /switchboard/status endpoint, so you can wire it into your own health and debug surfaces.

Which shape to pick