feat(server): role based authentication system (#2434)

- Parse toml configuration file, see https://github.com/qdm12/gluetun-wiki/blob/main/setup/advanced/control-server.md#authentication
- Retro-compatible with existing AND documented routes, until after v3.41 release
- Log a warning if an unprotected-by-default route is accessed unprotected
- Authentication methods: none, apikey, basic
- `genkey` command to generate API keys
- move log middleware to internal/server/middlewares/log

Co-authored-by: Joe Jose <45399349+joejose97@users.noreply.github.com>

internal/server/handler.go

@@ -2,13 +2,17 @@ package server
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 	"strings"
 
 	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/server/middlewares/auth"
+	"github.com/qdm12/gluetun/internal/server/middlewares/log"
 )
 
-func newHandler(ctx context.Context, logger infoWarner, logging bool,
+func newHandler(ctx context.Context, logger Logger, logging bool,
+	authSettings auth.Settings,
 	buildInfo models.BuildInformation,
 	vpnLooper VPNLooper,
 	pfGetter PortForwardedGetter,
@@ -17,7 +21,7 @@ func newHandler(ctx context.Context, logger infoWarner, logging bool,
 	publicIPLooper PublicIPLoop,
 	storage Storage,
 	ipv6Supported bool,
-) http.Handler {
+) (httpHandler http.Handler, err error) {
 	handler := &handler{}
 
 	vpn := newVPNHandler(ctx, vpnLooper, storage, ipv6Supported, logger)
@@ -29,16 +33,25 @@ func newHandler(ctx context.Context, logger infoWarner, logging bool,
 	handler.v0 = newHandlerV0(ctx, logger, vpnLooper, unboundLooper, updaterLooper)
 	handler.v1 = newHandlerV1(logger, buildInfo, vpn, openvpn, dns, updater, publicip)
 
-	handlerWithLog := withLogMiddleware(handler, logger, logging)
-	handler.setLogEnabled = handlerWithLog.setEnabled
+	authMiddleware, err := auth.New(authSettings, logger)
+	if err != nil {
+		return nil, fmt.Errorf("creating auth middleware: %w", err)
+	}
 
-	return handlerWithLog
+	middlewares := []func(http.Handler) http.Handler{
+		authMiddleware,
+		log.New(logger, logging),
+	}
+	httpHandler = handler
+	for _, middleware := range middlewares {
+		httpHandler = middleware(httpHandler)
+	}
+	return httpHandler, nil
 }
 
 type handler struct {
-	v0            http.Handler
-	v1            http.Handler
-	setLogEnabled func(enabled bool)
+	v0 http.Handler
+	v1 http.Handler
 }
 
 func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {