From 758b1ba1cbcd13fcff10954a301b7773f5921f20 Mon Sep 17 00:00:00 2001
From: Juan Font Alonso <juanfontalonso@gmail.com>
Date: Sat, 5 Mar 2022 16:22:02 +0100
Subject: [PATCH] Renamed configuration items of the DERP server

---
 app.go                     | 50 ++++++++++++++++++++++++++------------
 cmd/headscale/cli/utils.go |  9 +++----
 config-example.yaml        |  8 ++++++
 3 files changed, 47 insertions(+), 20 deletions(-)

diff --git a/app.go b/app.go
index eb3b8ad..b739a05 100644
--- a/app.go
+++ b/app.go
@@ -13,6 +13,7 @@ import (
 	"os"
 	"os/signal"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 	"syscall"
@@ -120,7 +121,8 @@ type OIDCConfig struct {
 }
 
 type DERPConfig struct {
-	EmbeddedDERP    bool
+	ServerEnabled   bool
+	ServerInsecure  bool
 	URLs            []url.URL
 	Paths           []string
 	AutoUpdate      bool
@@ -143,8 +145,8 @@ type Headscale struct {
 	dbDebug    bool
 	privateKey *key.MachinePrivate
 
-	DERPMap            *tailcfg.DERPMap
-	EmbeddedDERPServer *EmbeddedDERPServer
+	DERPMap    *tailcfg.DERPMap
+	DERPServer *DERPServer
 
 	aclPolicy *ACLPolicy
 	aclRules  []tailcfg.FilterRule
@@ -180,7 +182,6 @@ func LookupTLSClientAuthMode(mode string) (tls.ClientAuthType, bool) {
 	}
 }
 
-// NewHeadscale returns the Headscale app.
 func NewHeadscale(cfg Config) (*Headscale, error) {
 	privKey, err := readOrCreatePrivateKey(cfg.PrivateKeyPath)
 	if err != nil {
@@ -241,30 +242,49 @@ func NewHeadscale(cfg Config) (*Headscale, error) {
 		}
 	}
 
-	if cfg.DERP.EmbeddedDERP {
-		embeddedDERPServer, err := app.NewEmbeddedDERPServer()
+	if cfg.DERP.ServerEnabled {
+		embeddedDERPServer, err := app.NewDERPServer()
 		if err != nil {
 			return nil, err
 		}
-		app.EmbeddedDERPServer = embeddedDERPServer
+		app.DERPServer = embeddedDERPServer
 
-		// If we are using the embedded DERP, there is no reason to use Tailscale's DERP infrastructure
 		serverURL, err := url.Parse(app.cfg.ServerURL)
 		if err != nil {
 			return nil, err
 		}
+		var host string
+		var port int
+		host, portStr, err := net.SplitHostPort(serverURL.Host)
+		if err != nil {
+			if serverURL.Scheme == "https" {
+				host = serverURL.Host
+				port = 443
+			} else {
+				host = serverURL.Host
+				port = 80
+			}
+		} else {
+			port, err = strconv.Atoi(portStr)
+			if err != nil {
+				return nil, err
+			}
+		}
+
 		app.DERPMap = &tailcfg.DERPMap{
 			Regions: map[int]*tailcfg.DERPRegion{
-				1: {
-					RegionID:   1,
+				999: {
+					RegionID:   999,
 					RegionCode: "headscale",
 					RegionName: "Headscale Embedded DERP",
 					Avoid:      false,
 					Nodes: []*tailcfg.DERPNode{
 						{
-							Name:     "1a",
-							RegionID: 1,
-							HostName: serverURL.Host,
+							Name:             "999a",
+							RegionID:         999,
+							HostName:         host,
+							DERPPort:         port,
+							InsecureForTests: cfg.DERP.ServerInsecure,
 						},
 					},
 				},
@@ -495,7 +515,7 @@ func (h *Headscale) createRouter(grpcMux *runtime.ServeMux) *gin.Engine {
 	router.GET("/swagger", SwaggerUI)
 	router.GET("/swagger/v1/openapiv2.json", SwaggerAPIv1)
 
-	if h.cfg.DERP.EmbeddedDERP {
+	if h.cfg.DERP.ServerEnabled {
 		router.Any("/derp", h.EmbeddedDERPHandler)
 		router.Any("/derp/probe", h.EmbeddedDERPProbeHandler)
 		router.Any("/bootstrap-dns", h.EmbeddedDERPBootstrapDNSHandler)
@@ -516,7 +536,7 @@ func (h *Headscale) createRouter(grpcMux *runtime.ServeMux) *gin.Engine {
 func (h *Headscale) Serve() error {
 	var err error
 
-	if h.cfg.DERP.EmbeddedDERP {
+	if h.cfg.DERP.ServerEnabled {
 		go h.ServeSTUN()
 	} else {
 		// Fetch an initial DERP Map before we start serving
diff --git a/cmd/headscale/cli/utils.go b/cmd/headscale/cli/utils.go
index 98ffe2e..06b9ca9 100644
--- a/cmd/headscale/cli/utils.go
+++ b/cmd/headscale/cli/utils.go
@@ -117,11 +117,8 @@ func LoadConfig(path string) error {
 }
 
 func GetDERPConfig() headscale.DERPConfig {
-	if viper.GetBool("derp.embedded_derp") {
-		return headscale.DERPConfig{
-			EmbeddedDERP: true,
-		}
-	}
+	enabled := viper.GetBool("derp.server.enabled")
+	insecure := viper.GetBool("derp.server.insecure")
 
 	urlStrs := viper.GetStringSlice("derp.urls")
 
@@ -144,6 +141,8 @@ func GetDERPConfig() headscale.DERPConfig {
 	updateFrequency := viper.GetDuration("derp.update_frequency")
 
 	return headscale.DERPConfig{
+		ServerEnabled:   enabled,
+		ServerInsecure:  insecure,
 		URLs:            urls,
 		Paths:           paths,
 		AutoUpdate:      autoUpdate,
diff --git a/config-example.yaml b/config-example.yaml
index c28b608..84b1c90 100644
--- a/config-example.yaml
+++ b/config-example.yaml
@@ -55,6 +55,14 @@ ip_prefixes:
 # headscale needs a list of DERP servers that can be presented
 # to the clients.
 derp:
+  server:
+    # If enabled, runs the embedded DERP server and merges it into the rest of the DERP config
+    enabled: false
+
+    # Insecure mode is recommended only for tests. It indicates the tailscale clients
+    # to use insecure connections to this server.
+    insecure: false
+
   # List of externally available DERP maps encoded in JSON
   urls:
     - https://controlplane.tailscale.com/derpmap/default