From ca9d37ed9a424308535ebb0500e8ece1807a6abd Mon Sep 17 00:00:00 2001
From: Kristoffer Dalby <kristoffer@tailscale.com>
Date: Fri, 14 Mar 2025 15:54:45 +0100
Subject: [PATCH] make traceroute func

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
---
 integration/route_test.go | 11 +++++++----
 integration/tailscale.go  |  1 +
 integration/tsic/tsic.go  | 15 +++++++++++++++
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/integration/route_test.go b/integration/route_test.go
index be1503e3..56144077 100644
--- a/integration/route_test.go
+++ b/integration/route_test.go
@@ -1036,6 +1036,10 @@ func assertNodeRouteCount(t *testing.T, node *v1.Node, announced, approved, subn
 	assert.Len(t, node.GetSubnetRoutes(), subnet)
 }
 
+// TestSubnetRouterMultiNetwork is an evolution of the subnet router test.
+// This test will set up multiple docker networks and use two isolated tailscale
+// clients and a service available in one of the networks to validate that a
+// subnet router is working as expected.
 func TestSubnetRouterMultiNetwork(t *testing.T) {
 	IntegrationSkip(t)
 	t.Parallel()
@@ -1130,8 +1134,7 @@ func TestSubnetRouterMultiNetwork(t *testing.T) {
 	assert.Len(t, nodes, 2)
 	assertNodeRouteCount(t, nodes[0], 1, 1, 1)
 
-	// Verify that no routes has been sent to the client,
-	// they are not yet enabled.
+	// Verify that the routes have been sent to the client.
 	status, err = user2c.Status()
 	require.NoError(t, err)
 
@@ -1159,8 +1162,8 @@ func TestSubnetRouterMultiNetwork(t *testing.T) {
 	require.NoError(t, err)
 	assert.Len(t, result, 13)
 
-	stdout, stderr, err := user2c.Execute([]string{"traceroute", webip.String()})
-	assert.Contains(t, stdout+stderr, user1c.MustIPv4().String())
+	tr, err := user2c.Traceroute(webip)
+	assert.Contains(t, tr, user1c.MustIPv4().String())
 }
 
 // requirePeerSubnetRoutes asserts that the peer has the expected subnet routes.
diff --git a/integration/tailscale.go b/integration/tailscale.go
index 2b383c2c..804b6cda 100644
--- a/integration/tailscale.go
+++ b/integration/tailscale.go
@@ -41,6 +41,7 @@ type TailscaleClient interface {
 	WaitForPeers(expected int) error
 	Ping(hostnameOrIP string, opts ...tsic.PingOption) error
 	Curl(url string, opts ...tsic.CurlOption) (string, error)
+	Traceroute(netip.Addr) (string, error)
 	ID() string
 	ReadFile(path string) ([]byte, error)
 
diff --git a/integration/tsic/tsic.go b/integration/tsic/tsic.go
index 18373fc3..d1313ecb 100644
--- a/integration/tsic/tsic.go
+++ b/integration/tsic/tsic.go
@@ -1130,6 +1130,21 @@ func (t *TailscaleInContainer) Curl(url string, opts ...CurlOption) (string, err
 	return result, nil
 }
 
+func (t *TailscaleInContainer) Traceroute(ip netip.Addr) (string, error) {
+	command := []string{
+		"traceroute",
+		ip.String(),
+	}
+
+	var result string
+	result, _, err := t.Execute(command)
+	if err != nil {
+		return result, err
+	}
+
+	return result, nil
+}
+
 // WriteFile save file inside the Tailscale container.
 func (t *TailscaleInContainer) WriteFile(path string, data []byte) error {
 	return integrationutil.WriteFileToContainer(t.pool, t.container, path, data)