go-dns/service_test.go
Virgil 9919c70ed1 feat(dns): add fallback discoverer for dns.discover
Co-Authored-By: Virgil <virgil@lethean.io>
2026-04-03 19:54:47 +00:00

450 lines
12 KiB
Go

package dns
import (
"errors"
"strings"
"testing"
"time"
dnsprotocol "github.com/miekg/dns"
)
func exchangeWithRetry(t *testing.T, client dnsprotocol.Client, request *dnsprotocol.Msg, address string) *dnsprotocol.Msg {
t.Helper()
for attempt := 0; attempt < 80; attempt++ {
response, _, err := client.Exchange(request, address)
if err == nil {
return response
}
if !strings.Contains(err.Error(), "connection refused") {
t.Fatalf("dns query failed: %v", err)
}
time.Sleep(25 * time.Millisecond)
}
t.Fatalf("dns query failed after retrying due to startup timing")
return nil
}
func TestServiceResolveUsesExactNameBeforeWildcard(t *testing.T) {
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"*.charon.lthn": {
A: []string{"10.69.69.165"},
},
"gateway.charon.lthn": {
A: []string{"10.10.10.10"},
},
},
})
result, ok := service.Resolve("gateway.charon.lthn")
if !ok {
t.Fatal("expected exact record to resolve")
}
if len(result.A) != 1 || result.A[0] != "10.10.10.10" {
t.Fatalf("unexpected resolve result: %#v", result.A)
}
}
func TestServiceResolveUsesMostSpecificWildcard(t *testing.T) {
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"*.lthn": {
A: []string{"10.0.0.1"},
},
"*.charon.lthn": {
A: []string{"10.0.0.2"},
},
},
})
result, ok := service.Resolve("gateway.charon.lthn")
if !ok {
t.Fatal("expected wildcard record to resolve")
}
if len(result.A) != 1 || result.A[0] != "10.0.0.2" {
t.Fatalf("unexpected wildcard match: %#v", result.A)
}
}
func TestServiceResolveTXTUsesWildcard(t *testing.T) {
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"*.gateway.charon.lthn": {
TXT: []string{"v=lthn1 type=gateway"},
},
},
})
result, ok := service.ResolveTXT("node1.gateway.charon.lthn.")
if !ok {
t.Fatal("expected wildcard TXT record")
}
if len(result) != 1 || result[0] != "v=lthn1 type=gateway" {
t.Fatalf("unexpected TXT record: %#v", result)
}
}
func TestServiceResolveAddressReturnsMergedRecords(t *testing.T) {
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"gateway.charon.lthn": {
A: []string{"10.10.10.10", "10.10.10.10"},
AAAA: []string{"2600:1f1c:7f0:4f01:0000:0000:0000:0001"},
},
},
})
result, ok := service.ResolveAddress("gateway.charon.lthn")
if !ok {
t.Fatal("expected address record to resolve")
}
if len(result.Addresses) != 2 {
t.Fatalf("expected merged unique addresses, got %#v", result.Addresses)
}
if result.Addresses[0] != "10.10.10.10" || result.Addresses[1] != "2600:1f1c:7f0:4f01:0000:0000:0000:0001" {
t.Fatalf("unexpected address order or value: %#v", result.Addresses)
}
}
func TestServiceResolveAddressFallsBackToFalseWhenMissing(t *testing.T) {
service := NewService(ServiceOptions{})
if _, ok := service.ResolveAddress("missing.charon.lthn"); ok {
t.Fatal("expected missing record to return false")
}
}
func TestServiceResolveReverseUsesARecords(t *testing.T) {
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"gateway.charon.lthn": {
A: []string{"10.10.10.10"},
},
},
})
result, ok := service.ResolveReverse("10.10.10.10")
if !ok {
t.Fatal("expected reverse record to resolve")
}
if len(result) != 1 || result[0] != "gateway.charon.lthn" {
t.Fatalf("unexpected reverse result: %#v", result)
}
}
func TestServiceResolveReverseFallsBackToFalseWhenUnknown(t *testing.T) {
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"gateway.charon.lthn": {
A: []string{"10.10.10.10"},
},
},
})
if _, ok := service.ResolveReverse("10.10.10.11"); ok {
t.Fatal("expected no reverse match for unknown IP")
}
}
func TestServiceResolveReverseUsesSetAndRemove(t *testing.T) {
service := NewService(ServiceOptions{})
service.SetRecord("gateway.charon.lthn", NameRecords{
AAAA: []string{"2600:1f1c:7f0:4f01:0000:0000:0000:0001"},
})
result, ok := service.ResolveReverse("2600:1f1c:7f0:4f01::1")
if !ok || len(result) != 1 || result[0] != "gateway.charon.lthn" {
t.Fatalf("expected newly set reverse record, got %#v", result)
}
service.RemoveRecord("gateway.charon.lthn")
if _, ok := service.ResolveReverse("2600:1f1c:7f0:4f01::1"); ok {
t.Fatal("expected removed reverse record to disappear")
}
}
func TestServiceHealthUsesDeterministicTreeRootAndUpdatesOnMutations(t *testing.T) {
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"gateway.charon.lthn": {
A: []string{"10.10.10.10", "10.0.0.1"},
NS: []string{"ns1.example.com"},
},
},
})
health := service.Health()
root, ok := health["tree_root"].(string)
if !ok || root == "" || root == "stubbed" {
t.Fatalf("expected computed tree root, got %#v", health["tree_root"])
}
healthRepeating := NewService(ServiceOptions{
Records: map[string]NameRecords{
"gateway.charon.lthn": {
NS: []string{"ns1.example.com"},
A: []string{"10.0.0.1", "10.10.10.10"},
},
},
}).Health()["tree_root"].(string)
if healthRepeating != root {
t.Fatalf("expected deterministic tree root, got %s and %s", healthRepeating, root)
}
service.SetRecord("gateway.charon.lthn", NameRecords{
A: []string{"10.10.10.11"},
})
updatedRoot, ok := service.Health()["tree_root"].(string)
if !ok || updatedRoot == root {
t.Fatalf("expected updated tree root after SetRecord, got %s", updatedRoot)
}
service.RemoveRecord("gateway.charon.lthn")
removedRoot, ok := service.Health()["tree_root"].(string)
if !ok || removedRoot == updatedRoot {
t.Fatalf("expected updated tree root after RemoveRecord, got %s", removedRoot)
}
}
func TestServiceDiscoverReplacesRecordsFromDiscoverer(t *testing.T) {
records := []map[string]NameRecords{
{
"gateway.charon.lthn": {
A: []string{"10.10.10.10"},
},
"*.lthn": {
A: []string{"10.0.0.1"},
},
},
}
index := 0
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"legacy.charon.lthn": {
A: []string{"10.11.11.11"},
},
},
Discoverer: func() (map[string]NameRecords, error) {
next := records[index%len(records)]
index++
return next, nil
},
})
if _, ok := service.Resolve("legacy.charon.lthn"); !ok {
t.Fatal("expected baseline record before discovery")
}
if err := service.Discover(); err != nil {
t.Fatalf("unexpected discover error: %v", err)
}
result, ok := service.Resolve("gateway.charon.lthn")
if !ok {
t.Fatal("expected discovered exact record")
}
if len(result.A) != 1 || result.A[0] != "10.10.10.10" {
t.Fatalf("unexpected discovered resolve result: %#v", result.A)
}
if _, ok := service.Resolve("legacy.unknown"); ok {
t.Fatal("expected replaced cache not to resolve via old record")
}
}
func TestServiceDiscoverFallsBackWhenPrimaryDiscovererFails(t *testing.T) {
primaryCalled := false
fallbackCalled := false
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"legacy.charon.lthn": {
A: []string{"10.11.11.11"},
},
},
Discoverer: func() (map[string]NameRecords, error) {
primaryCalled = true
return nil, errors.New("chain service unavailable")
},
FallbackDiscoverer: func() (map[string]NameRecords, error) {
fallbackCalled = true
return map[string]NameRecords{
"gateway.charon.lthn": {
A: []string{"10.10.10.10"},
},
}, nil
},
})
if err := service.Discover(); err != nil {
t.Fatalf("expected fallback discovery to succeed: %v", err)
}
if !primaryCalled {
t.Fatal("expected primary discoverer to be attempted")
}
if !fallbackCalled {
t.Fatal("expected fallback discoverer to run after primary failure")
}
result, ok := service.Resolve("gateway.charon.lthn")
if !ok {
t.Fatal("expected fallback record to resolve")
}
if len(result.A) != 1 || result.A[0] != "10.10.10.10" {
t.Fatalf("unexpected fallback resolve result: %#v", result.A)
}
if _, ok := service.Resolve("legacy.charon.lthn"); ok {
t.Fatal("expected legacy record to be replaced by fallback discovery")
}
}
func TestServiceDiscoverUsesFallbackOnlyWhenPrimaryMissing(t *testing.T) {
fallbackCalled := false
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"legacy.charon.lthn": {
A: []string{"10.11.11.11"},
},
},
FallbackDiscoverer: func() (map[string]NameRecords, error) {
fallbackCalled = true
return map[string]NameRecords{
"gateway.charon.lthn": {
A: []string{"10.10.10.20"},
},
}, nil
},
})
if err := service.Discover(); err != nil {
t.Fatalf("expected fallback discovery to run: %v", err)
}
if !fallbackCalled {
t.Fatal("expected fallback discoverer to run when primary is missing")
}
if _, ok := service.Resolve("gateway.charon.lthn"); !ok {
t.Fatal("expected fallback record to resolve")
}
}
func TestServiceDiscoverReturnsNilWithoutDiscoverer(t *testing.T) {
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"gateway.charon.lthn": {
A: []string{"10.10.10.10"},
},
},
})
if err := service.Discover(); err != nil {
t.Fatalf("expected no error when discoverer is missing: %v", err)
}
}
func TestServiceServeResolvesAAndAAAARecords(t *testing.T) {
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"gateway.charon.lthn": {
A: []string{"10.10.10.10"},
AAAA: []string{"2600:1f1c:7f0:4f01::1"},
},
},
})
srv, err := service.Serve("127.0.0.1", 0)
if err != nil {
t.Fatalf("expected server to start: %v", err)
}
defer func() { _ = srv.Close() }()
client := dnsprotocol.Client{}
query := func(qtype uint16) *dnsprotocol.Msg {
request := new(dnsprotocol.Msg)
request.SetQuestion("gateway.charon.lthn.", qtype)
response := exchangeWithRetry(t, client, request, srv.Address())
if response.Rcode != dnsprotocol.RcodeSuccess {
t.Fatalf("unexpected rcode for qtype %d: %d", qtype, response.Rcode)
}
return response
}
aResponse := query(dnsprotocol.TypeA)
if len(aResponse.Answer) != 1 {
t.Fatalf("expected one A answer, got %d", len(aResponse.Answer))
}
if got, ok := aResponse.Answer[0].(*dnsprotocol.A); !ok || got.A.String() != "10.10.10.10" {
t.Fatalf("unexpected A answer: %#v", aResponse.Answer[0])
}
aaaaResponse := query(dnsprotocol.TypeAAAA)
if len(aaaaResponse.Answer) != 1 {
t.Fatalf("expected one AAAA answer, got %d", len(aaaaResponse.Answer))
}
if got, ok := aaaaResponse.Answer[0].(*dnsprotocol.AAAA); !ok || got.AAAA.String() != "2600:1f1c:7f0:4f01::1" {
t.Fatalf("unexpected AAAA answer: %#v", aaaaResponse.Answer[0])
}
}
func TestServiceServeResolvesWildcardAndPTRRecords(t *testing.T) {
service := NewService(ServiceOptions{
Records: map[string]NameRecords{
"*.charon.lthn": {
A: []string{"10.0.0.1"},
},
"gateway.charon.lthn": {
A: []string{"10.10.10.10"},
},
},
})
srv, err := service.Serve("127.0.0.1", 0)
if err != nil {
t.Fatalf("expected server to start: %v", err)
}
defer func() { _ = srv.Close() }()
client := dnsprotocol.Client{}
request := new(dnsprotocol.Msg)
request.SetQuestion("node1.charon.lthn.", dnsprotocol.TypeA)
response := exchangeWithRetry(t, client, request, srv.Address())
if response.Rcode != dnsprotocol.RcodeSuccess {
t.Fatalf("unexpected rcode: %d", response.Rcode)
}
if got, ok := response.Answer[0].(*dnsprotocol.A); !ok || got.A.String() != "10.0.0.1" {
t.Fatalf("unexpected wildcard A answer: %#v", response.Answer)
}
ptrName := "10.10.10.10.in-addr.arpa."
ptrRequest := new(dnsprotocol.Msg)
ptrRequest.SetQuestion(ptrName, dnsprotocol.TypePTR)
ptrResponse := exchangeWithRetry(t, client, ptrRequest, srv.Address())
if len(ptrResponse.Answer) == 0 {
t.Fatal("expected PTR answer")
}
if got, ok := ptrResponse.Answer[0].(*dnsprotocol.PTR); !ok || got.Ptr != "gateway.charon.lthn." {
t.Fatalf("unexpected PTR answer: %#v", ptrResponse.Answer)
}
}
func TestServiceServeReturnsNXDOMAINWhenMissing(t *testing.T) {
service := NewService(ServiceOptions{})
srv, err := service.Serve("127.0.0.1", 0)
if err != nil {
t.Fatalf("expected server to start: %v", err)
}
defer func() { _ = srv.Close() }()
client := dnsprotocol.Client{}
request := new(dnsprotocol.Msg)
request.SetQuestion("missing.charon.lthn.", dnsprotocol.TypeA)
response := exchangeWithRetry(t, client, request, srv.Address())
if response.Rcode != dnsprotocol.RcodeNameError {
t.Fatalf("expected NXDOMAIN, got %d", response.Rcode)
}
}