Files
headscale/hscontrol/derp/derp_test.go
copilot-swe-agent[bot] 18fb3f00a8 Add additional test cases to verify different base domains produce different shuffle orders
Added two more test cases with the same dataset (region 4) but different base domains to ensure the shuffle is truly deterministic and that different seeds produce different results.

Co-authored-by: kradalby <98431+kradalby@users.noreply.github.com>
2025-11-01 07:39:15 +00:00

351 lines
9.7 KiB
Go

package derp
import (
"testing"
"github.com/google/go-cmp/cmp"
"github.com/spf13/viper"
"tailscale.com/tailcfg"
)
func TestShuffleDERPMapDeterministic(t *testing.T) {
tests := []struct {
name string
baseDomain string
derpMap *tailcfg.DERPMap
expected *tailcfg.DERPMap
}{
{
name: "single region with 4 nodes",
baseDomain: "test1.example.com",
derpMap: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
1: {
RegionID: 1,
RegionCode: "nyc",
RegionName: "New York City",
Nodes: []*tailcfg.DERPNode{
{Name: "1f", RegionID: 1, HostName: "derp1f.tailscale.com"},
{Name: "1g", RegionID: 1, HostName: "derp1g.tailscale.com"},
{Name: "1h", RegionID: 1, HostName: "derp1h.tailscale.com"},
{Name: "1i", RegionID: 1, HostName: "derp1i.tailscale.com"},
},
},
},
},
expected: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
1: {
RegionID: 1,
RegionCode: "nyc",
RegionName: "New York City",
Nodes: []*tailcfg.DERPNode{
{Name: "1g", RegionID: 1, HostName: "derp1g.tailscale.com"},
{Name: "1f", RegionID: 1, HostName: "derp1f.tailscale.com"},
{Name: "1i", RegionID: 1, HostName: "derp1i.tailscale.com"},
{Name: "1h", RegionID: 1, HostName: "derp1h.tailscale.com"},
},
},
},
},
},
{
name: "multiple regions with nodes",
baseDomain: "test2.example.com",
derpMap: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
10: {
RegionID: 10,
RegionCode: "sea",
RegionName: "Seattle",
Nodes: []*tailcfg.DERPNode{
{Name: "10b", RegionID: 10, HostName: "derp10b.tailscale.com"},
{Name: "10c", RegionID: 10, HostName: "derp10c.tailscale.com"},
{Name: "10d", RegionID: 10, HostName: "derp10d.tailscale.com"},
},
},
2: {
RegionID: 2,
RegionCode: "sfo",
RegionName: "San Francisco",
Nodes: []*tailcfg.DERPNode{
{Name: "2d", RegionID: 2, HostName: "derp2d.tailscale.com"},
{Name: "2e", RegionID: 2, HostName: "derp2e.tailscale.com"},
{Name: "2f", RegionID: 2, HostName: "derp2f.tailscale.com"},
},
},
},
},
expected: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
10: {
RegionID: 10,
RegionCode: "sea",
RegionName: "Seattle",
Nodes: []*tailcfg.DERPNode{
{Name: "10d", RegionID: 10, HostName: "derp10d.tailscale.com"},
{Name: "10c", RegionID: 10, HostName: "derp10c.tailscale.com"},
{Name: "10b", RegionID: 10, HostName: "derp10b.tailscale.com"},
},
},
2: {
RegionID: 2,
RegionCode: "sfo",
RegionName: "San Francisco",
Nodes: []*tailcfg.DERPNode{
{Name: "2d", RegionID: 2, HostName: "derp2d.tailscale.com"},
{Name: "2e", RegionID: 2, HostName: "derp2e.tailscale.com"},
{Name: "2f", RegionID: 2, HostName: "derp2f.tailscale.com"},
},
},
},
},
},
{
name: "large region with many nodes",
baseDomain: "test3.example.com",
derpMap: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
4: {
RegionID: 4,
RegionCode: "fra",
RegionName: "Frankfurt",
Nodes: []*tailcfg.DERPNode{
{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
},
},
},
},
expected: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
4: {
RegionID: 4,
RegionCode: "fra",
RegionName: "Frankfurt",
Nodes: []*tailcfg.DERPNode{
{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
},
},
},
},
},
{
name: "same region different base domain",
baseDomain: "different.example.com",
derpMap: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
4: {
RegionID: 4,
RegionCode: "fra",
RegionName: "Frankfurt",
Nodes: []*tailcfg.DERPNode{
{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
},
},
},
},
expected: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
4: {
RegionID: 4,
RegionCode: "fra",
RegionName: "Frankfurt",
Nodes: []*tailcfg.DERPNode{
{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
},
},
},
},
},
{
name: "same dataset with another base domain",
baseDomain: "another.example.com",
derpMap: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
4: {
RegionID: 4,
RegionCode: "fra",
RegionName: "Frankfurt",
Nodes: []*tailcfg.DERPNode{
{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
},
},
},
},
expected: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
4: {
RegionID: 4,
RegionCode: "fra",
RegionName: "Frankfurt",
Nodes: []*tailcfg.DERPNode{
{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
},
},
},
},
},
{
name: "same dataset with yet another base domain",
baseDomain: "yetanother.example.com",
derpMap: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
4: {
RegionID: 4,
RegionCode: "fra",
RegionName: "Frankfurt",
Nodes: []*tailcfg.DERPNode{
{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
},
},
},
},
expected: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
4: {
RegionID: 4,
RegionCode: "fra",
RegionName: "Frankfurt",
Nodes: []*tailcfg.DERPNode{
{Name: "4i", RegionID: 4, HostName: "derp4i.tailscale.com"},
{Name: "4h", RegionID: 4, HostName: "derp4h.tailscale.com"},
{Name: "4f", RegionID: 4, HostName: "derp4f.tailscale.com"},
{Name: "4g", RegionID: 4, HostName: "derp4g.tailscale.com"},
},
},
},
},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
viper.Set("dns.base_domain", tt.baseDomain)
defer viper.Reset()
resetDerpRandomForTesting()
testMap := tt.derpMap.View().AsStruct()
shuffleDERPMap(testMap)
if diff := cmp.Diff(tt.expected, testMap); diff != "" {
t.Errorf("Shuffled DERP map doesn't match expected (-expected +actual):\n%s", diff)
}
})
}
}
func TestShuffleDERPMapEdgeCases(t *testing.T) {
tests := []struct {
name string
derpMap *tailcfg.DERPMap
}{
{
name: "nil derp map",
derpMap: nil,
},
{
name: "empty derp map",
derpMap: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{},
},
},
{
name: "region with no nodes",
derpMap: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
1: {
RegionID: 1,
RegionCode: "empty",
RegionName: "Empty Region",
Nodes: []*tailcfg.DERPNode{},
},
},
},
},
{
name: "region with single node",
derpMap: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
1: {
RegionID: 1,
RegionCode: "single",
RegionName: "Single Node Region",
Nodes: []*tailcfg.DERPNode{
{Name: "1a", RegionID: 1, HostName: "derp1a.tailscale.com"},
},
},
},
},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
shuffleDERPMap(tt.derpMap)
})
}
}
func TestShuffleDERPMapWithoutBaseDomain(t *testing.T) {
viper.Reset()
resetDerpRandomForTesting()
derpMap := &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
1: {
RegionID: 1,
RegionCode: "test",
RegionName: "Test Region",
Nodes: []*tailcfg.DERPNode{
{Name: "1a", RegionID: 1, HostName: "derp1a.test.com"},
{Name: "1b", RegionID: 1, HostName: "derp1b.test.com"},
{Name: "1c", RegionID: 1, HostName: "derp1c.test.com"},
{Name: "1d", RegionID: 1, HostName: "derp1d.test.com"},
},
},
},
}
original := derpMap.View().AsStruct()
shuffleDERPMap(derpMap)
if len(derpMap.Regions) != 1 || len(derpMap.Regions[1].Nodes) != 4 {
t.Error("Shuffle corrupted DERP map structure")
}
originalNodes := make(map[string]bool)
for _, node := range original.Regions[1].Nodes {
originalNodes[node.Name] = true
}
shuffledNodes := make(map[string]bool)
for _, node := range derpMap.Regions[1].Nodes {
shuffledNodes[node.Name] = true
}
if diff := cmp.Diff(originalNodes, shuffledNodes); diff != "" {
t.Errorf("Shuffle changed node set (-original +shuffled):\n%s", diff)
}
}