From ece907d878fc6fd08085fbed796eba35dfe103fa Mon Sep 17 00:00:00 2001
From: Kristoffer Dalby <kristoffer@dalby.cc>
Date: Sun, 11 Aug 2024 07:44:59 +0200
Subject: [PATCH] test embedded derp with derp updater, check client health
 (#2030)

---
 hscontrol/derp/derp.go            |  5 ---
 integration/embedded_derp_test.go | 64 ++++++++++++++++++++++++++++---
 2 files changed, 58 insertions(+), 11 deletions(-)

diff --git a/hscontrol/derp/derp.go b/hscontrol/derp/derp.go
index 3afcb4e..5d4b24f 100644
--- a/hscontrol/derp/derp.go
+++ b/hscontrol/derp/derp.go
@@ -125,10 +125,5 @@ func GetDERPMap(cfg types.DERPConfig) *tailcfg.DERPMap {
 
 	log.Trace().Interface("derpMap", derpMap).Msg("DERPMap loaded")
 
-	if len(derpMap.Regions) == 0 {
-		log.Warn().
-			Msg("DERP map is empty, not a single DERP map datasource was loaded correctly or contained a region")
-	}
-
 	return derpMap
 }
diff --git a/integration/embedded_derp_test.go b/integration/embedded_derp_test.go
index 39a9acc..745f2c8 100644
--- a/integration/embedded_derp_test.go
+++ b/integration/embedded_derp_test.go
@@ -4,7 +4,9 @@ import (
 	"fmt"
 	"log"
 	"net/url"
+	"strings"
 	"testing"
+	"time"
 
 	"github.com/juanfont/headscale/hscontrol/util"
 	"github.com/juanfont/headscale/integration/dockertestutil"
@@ -33,8 +35,7 @@ func TestDERPServerScenario(t *testing.T) {
 	defer scenario.Shutdown()
 
 	spec := map[string]int{
-		"user1": 10,
-		// "user1": len(MustTestVersions),
+		"user1": len(MustTestVersions),
 	}
 
 	err = scenario.CreateHeadscaleEnv(
@@ -44,24 +45,75 @@ func TestDERPServerScenario(t *testing.T) {
 		hsic.WithEmbeddedDERPServerOnly(),
 		hsic.WithTLS(),
 		hsic.WithHostnameAsServerURL(),
+		hsic.WithConfigEnv(map[string]string{
+			"HEADSCALE_DERP_AUTO_UPDATE_ENABLED": "true",
+			"HEADSCALE_DERP_UPDATE_FREQUENCY":    "10s",
+		}),
 	)
 	assertNoErrHeadscaleEnv(t, err)
 
 	allClients, err := scenario.ListTailscaleClients()
 	assertNoErrListClients(t, err)
 
-	allIps, err := scenario.ListTailscaleClientsIPs()
-	assertNoErrListClientIPs(t, err)
-
 	err = scenario.WaitForTailscaleSync()
 	assertNoErrSync(t, err)
 
 	allHostnames, err := scenario.ListTailscaleClientsFQDNs()
 	assertNoErrListFQDN(t, err)
 
+	for _, client := range allClients {
+		status, err := client.Status()
+		assertNoErr(t, err)
+
+		for _, health := range status.Health {
+			if strings.Contains(health, "could not connect to any relay server") {
+				t.Errorf("expected to be connected to derp, found: %s", health)
+			}
+			if strings.Contains(health, "could not connect to the 'Headscale Embedded DERP' relay server.") {
+				t.Errorf("expected to be connected to derp, found: %s", health)
+			}
+		}
+	}
+
 	success := pingDerpAllHelper(t, allClients, allHostnames)
 
-	t.Logf("%d successful pings out of %d", success, len(allClients)*len(allIps))
+	for _, client := range allClients {
+		status, err := client.Status()
+		assertNoErr(t, err)
+
+		for _, health := range status.Health {
+			if strings.Contains(health, "could not connect to any relay server") {
+				t.Errorf("expected to be connected to derp, found: %s", health)
+			}
+			if strings.Contains(health, "could not connect to the 'Headscale Embedded DERP' relay server.") {
+				t.Errorf("expected to be connected to derp, found: %s", health)
+			}
+		}
+	}
+
+	t.Logf("Run 1: %d successful pings out of %d", success, len(allClients)*len(allHostnames))
+
+	// Let the DERP updater run a couple of times to ensure it does not
+	// break the DERPMap.
+	time.Sleep(30 * time.Second)
+
+	success = pingDerpAllHelper(t, allClients, allHostnames)
+
+	for _, client := range allClients {
+		status, err := client.Status()
+		assertNoErr(t, err)
+
+		for _, health := range status.Health {
+			if strings.Contains(health, "could not connect to any relay server") {
+				t.Errorf("expected to be connected to derp, found: %s", health)
+			}
+			if strings.Contains(health, "could not connect to the 'Headscale Embedded DERP' relay server.") {
+				t.Errorf("expected to be connected to derp, found: %s", health)
+			}
+		}
+	}
+
+	t.Logf("Run2: %d successful pings out of %d", success, len(allClients)*len(allHostnames))
 }
 
 func (s *EmbeddedDERPServerScenario) CreateHeadscaleEnv(