early progress on embedded Caddy for --backend-mode web (#392)

endpoints/proxy/caddyWebBackend.go

@@ -0,0 +1,69 @@
+package proxy
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/caddyserver/caddy/v2"
+	"github.com/caddyserver/caddy/v2/caddyconfig"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp/fileserver"
+	"github.com/openziti/zrok/endpoints"
+	"time"
+)
+
+type CaddyWebBackendConfig struct {
+	IdentityPath string
+	WebRoot      string
+	ShrToken     string
+	Requests     chan *endpoints.Request
+}
+
+type CaddyWebBackend struct {
+	cfg      *CaddyWebBackendConfig
+	caddyCfg *caddy.Config
+}
+
+func NewCaddyWebBackend(cfg *CaddyWebBackendConfig) (*CaddyWebBackend, error) {
+	handler := fileserver.FileServer{Root: cfg.WebRoot}
+	handler.Browse = new(fileserver.Browse)
+
+	var handlers []json.RawMessage
+	handlers = append(handlers, caddyconfig.JSONModuleObject(handler, "handler", "file_server", nil))
+
+	route := caddyhttp.Route{HandlersRaw: handlers}
+
+	server := &caddyhttp.Server{
+		ReadHeaderTimeout: caddy.Duration(10 * time.Second),
+		IdleTimeout:       caddy.Duration(30 * time.Second),
+		MaxHeaderBytes:    1024 * 10,
+		Routes:            caddyhttp.RouteList{route},
+	}
+	server.Listen = []string{fmt.Sprintf("zrok/%s", cfg.ShrToken)}
+
+	httpApp := caddyhttp.App{
+		Servers: map[string]*caddyhttp.Server{"static": server},
+	}
+
+	var false bool
+	caddyCfg := &caddy.Config{
+		Admin: &caddy.AdminConfig{
+			Disabled: true,
+			Config: &caddy.ConfigSettings{
+				Persist: &false,
+			},
+		},
+		AppsRaw: caddy.ModuleMap{
+			"http": caddyconfig.JSON(httpApp, nil),
+		},
+	}
+
+	return &CaddyWebBackend{cfg: cfg, caddyCfg: caddyCfg}, nil
+}
+
+func (c *CaddyWebBackend) Run() error {
+	return caddy.Run(c.caddyCfg)
+}
+
+func (c *CaddyWebBackend) Requests() func() int32 {
+	return func() int32 { return 0 }
+}