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-rw-r--r--plugin/k8s_external/README.md12
-rw-r--r--plugin/k8s_external/apex.go2
-rw-r--r--plugin/k8s_external/apex_test.go27
-rw-r--r--plugin/k8s_external/external.go12
-rw-r--r--plugin/k8s_external/external_test.go41
-rw-r--r--plugin/k8s_external/setup.go2
-rw-r--r--plugin/k8s_external/transfer.go97
-rw-r--r--plugin/k8s_external/transfer_test.go142
8 files changed, 318 insertions, 17 deletions
diff --git a/plugin/k8s_external/README.md b/plugin/k8s_external/README.md
index 0faaca3cf..c7df91abc 100644
--- a/plugin/k8s_external/README.md
+++ b/plugin/k8s_external/README.md
@@ -83,6 +83,18 @@ spec:
type: ClusterIP
~~~
+The *k8s_external* plugin can be used in conjunction with the *transfer* plugin to enable
+zone transfers. Notifies are not supported.
+
+ ~~~
+ . {
+ transfer example.org {
+ to *
+ }
+ kubernetes cluster.local
+ k8s_external example.org
+ }
+ ~~~
# See Also
diff --git a/plugin/k8s_external/apex.go b/plugin/k8s_external/apex.go
index 85edbea6c..0ce00a7c3 100644
--- a/plugin/k8s_external/apex.go
+++ b/plugin/k8s_external/apex.go
@@ -93,7 +93,7 @@ func (e *External) soa(state request.Request) *dns.SOA {
soa := &dns.SOA{Hdr: header,
Mbox: dnsutil.Join(e.hostmaster, e.apex, state.Zone),
Ns: dnsutil.Join("ns1", e.apex, state.Zone),
- Serial: 12345, // Also dynamic?
+ Serial: e.externalSerialFunc(state.Zone),
Refresh: 7200,
Retry: 1800,
Expire: 86400,
diff --git a/plugin/k8s_external/apex_test.go b/plugin/k8s_external/apex_test.go
index 2f6923f56..45b835e3a 100644
--- a/plugin/k8s_external/apex_test.go
+++ b/plugin/k8s_external/apex_test.go
@@ -20,7 +20,8 @@ func TestApex(t *testing.T) {
e.Zones = []string{"example.com."}
e.Next = test.NextHandler(dns.RcodeSuccess, nil)
e.externalFunc = k.External
- e.externalAddrFunc = externalAddress // internal test function
+ e.externalAddrFunc = externalAddress // internal test function
+ e.externalSerialFunc = externalSerial // internal test function
ctx := context.TODO()
for i, tc := range testsApex {
@@ -43,6 +44,16 @@ func TestApex(t *testing.T) {
if err := test.SortAndCheck(resp, tc); err != nil {
t.Error(err)
}
+ for i, rr := range tc.Ns {
+ expectsoa := rr.(*dns.SOA)
+ gotsoa, ok := resp.Ns[i].(*dns.SOA)
+ if !ok {
+ t.Fatalf("Unexpected record type in Authority section")
+ }
+ if expectsoa.Serial != gotsoa.Serial {
+ t.Fatalf("Expected soa serial %d, got %d", expectsoa.Serial, gotsoa.Serial)
+ }
+ }
}
}
@@ -50,7 +61,7 @@ var testsApex = []test.Case{
{
Qname: "example.com.", Qtype: dns.TypeSOA, Rcode: dns.RcodeSuccess,
Answer: []dns.RR{
- test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.example.com. 1499347823 7200 1800 86400 5"),
+ test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.dns.example.com. 1499347823 7200 1800 86400 5"),
},
},
{
@@ -65,37 +76,37 @@ var testsApex = []test.Case{
{
Qname: "example.com.", Qtype: dns.TypeSRV, Rcode: dns.RcodeSuccess,
Ns: []dns.RR{
- test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.example.com. 1499347823 7200 1800 86400 5"),
+ test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.dns.example.com. 1499347823 7200 1800 86400 5"),
},
},
{
Qname: "dns.example.com.", Qtype: dns.TypeSRV, Rcode: dns.RcodeSuccess,
Ns: []dns.RR{
- test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.example.com. 1499347823 7200 1800 86400 5"),
+ test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.dns.example.com. 1499347823 7200 1800 86400 5"),
},
},
{
Qname: "dns.example.com.", Qtype: dns.TypeNS, Rcode: dns.RcodeSuccess,
Ns: []dns.RR{
- test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.example.com. 1499347823 7200 1800 86400 5"),
+ test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.dns.example.com. 1499347823 7200 1800 86400 5"),
},
},
{
Qname: "ns1.dns.example.com.", Qtype: dns.TypeSRV, Rcode: dns.RcodeSuccess,
Ns: []dns.RR{
- test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.example.com. 1499347823 7200 1800 86400 5"),
+ test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.dns.example.com. 1499347823 7200 1800 86400 5"),
},
},
{
Qname: "ns1.dns.example.com.", Qtype: dns.TypeNS, Rcode: dns.RcodeSuccess,
Ns: []dns.RR{
- test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.example.com. 1499347823 7200 1800 86400 5"),
+ test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.dns.example.com. 1499347823 7200 1800 86400 5"),
},
},
{
Qname: "ns1.dns.example.com.", Qtype: dns.TypeAAAA, Rcode: dns.RcodeSuccess,
Ns: []dns.RR{
- test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.example.com. 1499347823 7200 1800 86400 5"),
+ test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.dns.example.com. 1499347823 7200 1800 86400 5"),
},
},
{
diff --git a/plugin/k8s_external/external.go b/plugin/k8s_external/external.go
index 720556969..c584b3414 100644
--- a/plugin/k8s_external/external.go
+++ b/plugin/k8s_external/external.go
@@ -29,9 +29,13 @@ type Externaler interface {
External(request.Request) ([]msg.Service, int)
// ExternalAddress should return a string slice of addresses for the nameserving endpoint.
ExternalAddress(state request.Request) []dns.RR
+ // ExternalServices returns all services in the given zone as a slice of msg.Service.
+ ExternalServices(zone string) []msg.Service
+ // ExternalSerial gets the current serial.
+ ExternalSerial(string) uint32
}
-// External resolves Ingress and Loadbalance IPs from kubernetes clusters.
+// External serves records for External IPs and Loadbalance IPs of Services in Kubernetes clusters.
type External struct {
Next plugin.Handler
Zones []string
@@ -42,8 +46,10 @@ type External struct {
upstream *upstream.Upstream
- externalFunc func(request.Request) ([]msg.Service, int)
- externalAddrFunc func(request.Request) []dns.RR
+ externalFunc func(request.Request) ([]msg.Service, int)
+ externalAddrFunc func(request.Request) []dns.RR
+ externalSerialFunc func(string) uint32
+ externalServicesFunc func(string) []msg.Service
}
// New returns a new and initialized *External.
diff --git a/plugin/k8s_external/external_test.go b/plugin/k8s_external/external_test.go
index cc29fd7a6..7c7ee8069 100644
--- a/plugin/k8s_external/external_test.go
+++ b/plugin/k8s_external/external_test.go
@@ -23,7 +23,8 @@ func TestExternal(t *testing.T) {
e.Zones = []string{"example.com."}
e.Next = test.NextHandler(dns.RcodeSuccess, nil)
e.externalFunc = k.External
- e.externalAddrFunc = externalAddress // internal test function
+ e.externalAddrFunc = externalAddress // internal test function
+ e.externalSerialFunc = externalSerial // internal test function
ctx := context.TODO()
for i, tc := range tests {
@@ -147,6 +148,7 @@ var tests = []test.Case{
test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.example.com. 1499347823 7200 1800 86400 5"),
},
},
+ // svc11
{
Qname: "svc11.testns.example.com.", Qtype: dns.TypeA, Rcode: dns.RcodeSuccess,
Answer: []dns.RR{
@@ -154,17 +156,42 @@ var tests = []test.Case{
},
},
{
- Qname: "_http._tcp.svc12.testns.example.com.", Qtype: dns.TypeSRV, Rcode: dns.RcodeSuccess,
+ Qname: "_http._tcp.svc11.testns.example.com.", Qtype: dns.TypeSRV, Rcode: dns.RcodeSuccess,
Answer: []dns.RR{
- test.SRV("_http._tcp.svc12.testns.example.com. 5 IN SRV 0 100 80 dummy.hostname."),
+ test.SRV("_http._tcp.svc11.testns.example.com. 5 IN SRV 0 100 80 svc11.testns.example.com."),
+ },
+ Extra: []dns.RR{
+ test.A("svc11.testns.example.com. 5 IN A 1.2.3.4"),
+ },
+ },
+ {
+ Qname: "svc11.testns.example.com.", Qtype: dns.TypeSRV, Rcode: dns.RcodeSuccess,
+ Answer: []dns.RR{
+ test.SRV("svc11.testns.example.com. 5 IN SRV 0 100 80 svc11.testns.example.com."),
+ },
+ Extra: []dns.RR{
+ test.A("svc11.testns.example.com. 5 IN A 1.2.3.4"),
},
},
+ // svc12
{
Qname: "svc12.testns.example.com.", Qtype: dns.TypeA, Rcode: dns.RcodeSuccess,
Answer: []dns.RR{
test.CNAME("svc12.testns.example.com. 5 IN CNAME dummy.hostname"),
},
},
+ {
+ Qname: "_http._tcp.svc12.testns.example.com.", Qtype: dns.TypeSRV, Rcode: dns.RcodeSuccess,
+ Answer: []dns.RR{
+ test.SRV("_http._tcp.svc12.testns.example.com. 5 IN SRV 0 100 80 dummy.hostname."),
+ },
+ },
+ {
+ Qname: "svc12.testns.example.com.", Qtype: dns.TypeSRV, Rcode: dns.RcodeSuccess,
+ Answer: []dns.RR{
+ test.SRV("svc12.testns.example.com. 5 IN SRV 0 100 80 dummy.hostname."),
+ },
+ },
}
type external struct{}
@@ -173,8 +200,8 @@ func (external) HasSynced() bool
func (external) Run() {}
func (external) Stop() error { return nil }
func (external) EpIndexReverse(string) []*object.Endpoints { return nil }
-func (external) SvcIndexReverse(string) []*object.Service { return nil }
-func (external) Modified() int64 { return 0 }
+func (external) SvcIndexReverse(string) []*object.Service { return nil }
+func (external) Modified(bool) int64 { return 0 }
func (external) EpIndex(s string) []*object.Endpoints { return nil }
func (external) EndpointsList() []*object.Endpoints { return nil }
func (external) GetNodeByName(ctx context.Context, name string) (*api.Node, error) { return nil, nil }
@@ -240,3 +267,7 @@ func externalAddress(state request.Request) []dns.RR {
a := test.A("example.org. IN A 127.0.0.1")
return []dns.RR{a}
}
+
+func externalSerial(string) uint32 {
+ return 1499347823
+}
diff --git a/plugin/k8s_external/setup.go b/plugin/k8s_external/setup.go
index 1f408dc80..e8a333422 100644
--- a/plugin/k8s_external/setup.go
+++ b/plugin/k8s_external/setup.go
@@ -26,6 +26,8 @@ func setup(c *caddy.Controller) error {
if x, ok := m.(Externaler); ok {
e.externalFunc = x.External
e.externalAddrFunc = x.ExternalAddress
+ e.externalServicesFunc = x.ExternalServices
+ e.externalSerialFunc = x.ExternalSerial
}
return nil
})
diff --git a/plugin/k8s_external/transfer.go b/plugin/k8s_external/transfer.go
new file mode 100644
index 000000000..9c2c231f9
--- /dev/null
+++ b/plugin/k8s_external/transfer.go
@@ -0,0 +1,97 @@
+package external
+
+import (
+ "context"
+
+ "github.com/coredns/coredns/plugin"
+ "github.com/coredns/coredns/plugin/etcd/msg"
+ "github.com/coredns/coredns/plugin/transfer"
+ "github.com/coredns/coredns/request"
+
+ "github.com/miekg/dns"
+)
+
+// Transfer implements transfer.Transferer
+func (e *External) Transfer(zone string, serial uint32) (<-chan []dns.RR, error) {
+ z := plugin.Zones(e.Zones).Matches(zone)
+ if z != zone {
+ return nil, transfer.ErrNotAuthoritative
+ }
+
+ ctx := context.Background()
+ ch := make(chan []dns.RR, 2)
+ if zone == "." {
+ zone = ""
+ }
+ state := request.Request{Zone: zone}
+
+ // SOA
+ soa := e.soa(state)
+ ch <- []dns.RR{soa}
+ if serial != 0 && serial >= soa.Serial {
+ close(ch)
+ return ch, nil
+ }
+
+ go func() {
+ // Add NS
+ nsName := "ns1." + e.apex + "." + zone
+ nsHdr := dns.RR_Header{Name: zone, Rrtype: dns.TypeNS, Ttl: e.ttl, Class: dns.ClassINET}
+ ch <- []dns.RR{&dns.NS{Hdr: nsHdr, Ns: nsName}}
+
+ // Add Nameserver A/AAAA records
+ nsRecords := e.externalAddrFunc(state)
+ for i := range nsRecords {
+ // externalAddrFunc returns incomplete header names, correct here
+ nsRecords[i].Header().Name = nsName
+ nsRecords[i].Header().Ttl = e.ttl
+ ch <- []dns.RR{nsRecords[i]}
+ }
+
+ svcs := e.externalServicesFunc(zone)
+ srvSeen := make(map[string]struct{})
+ for i := range svcs {
+ name := msg.Domain(svcs[i].Key)
+ if svcs[i].TargetStrip == 0 {
+ // Add Service A/AAAA records
+ s := request.Request{Req: &dns.Msg{Question: []dns.Question{{Name: name}}}}
+ as := e.a(ctx, []msg.Service{svcs[i]}, s)
+ if len(as) > 0 {
+ ch <- as
+ }
+ aaaas := e.aaaa(ctx, []msg.Service{svcs[i]}, s)
+ if len(aaaas) > 0 {
+ ch <- aaaas
+ }
+ // Add bare SRV record, ensuring uniqueness
+ recs, _ := e.srv(ctx, []msg.Service{svcs[i]}, s)
+ for _, srv := range recs {
+ if !nameSeen(srvSeen, srv) {
+ ch <- []dns.RR{srv}
+ }
+ }
+ continue
+ }
+ // Add full SRV record, ensuring uniqueness
+ s := request.Request{Req: &dns.Msg{Question: []dns.Question{{Name: name}}}}
+ recs, _ := e.srv(ctx, []msg.Service{svcs[i]}, s)
+ for _, srv := range recs {
+ if !nameSeen(srvSeen, srv) {
+ ch <- []dns.RR{srv}
+ }
+ }
+ }
+ ch <- []dns.RR{soa}
+ close(ch)
+ }()
+
+ return ch, nil
+}
+
+func nameSeen(namesSeen map[string]struct{}, rr dns.RR) bool {
+ if _, duplicate := namesSeen[rr.Header().Name]; duplicate {
+ return true
+ }
+ namesSeen[rr.Header().Name] = struct{}{}
+ return false
+}
diff --git a/plugin/k8s_external/transfer_test.go b/plugin/k8s_external/transfer_test.go
new file mode 100644
index 000000000..c55f14c1f
--- /dev/null
+++ b/plugin/k8s_external/transfer_test.go
@@ -0,0 +1,142 @@
+package external
+
+import (
+ "strings"
+ "testing"
+
+ "github.com/coredns/coredns/plugin"
+ "github.com/coredns/coredns/plugin/kubernetes"
+ "github.com/coredns/coredns/plugin/test"
+ "github.com/coredns/coredns/plugin/transfer"
+
+ "github.com/miekg/dns"
+)
+
+func TestImplementsTransferer(t *testing.T) {
+ var e plugin.Handler
+ e = &External{}
+ _, ok := e.(transfer.Transferer)
+ if !ok {
+ t.Error("Transferer not implemented")
+ }
+}
+
+func TestTransferAXFR(t *testing.T) {
+ k := kubernetes.New([]string{"cluster.local."})
+ k.Namespaces = map[string]struct{}{"testns": {}}
+ k.APIConn = &external{}
+
+ e := New()
+ e.Zones = []string{"example.com."}
+ e.externalFunc = k.External
+ e.externalAddrFunc = externalAddress // internal test function
+ e.externalSerialFunc = externalSerial // internal test function
+ e.externalServicesFunc = k.ExternalServices
+
+ ch, err := e.Transfer("example.com.", 0)
+
+ if err != nil {
+ t.Fatalf("Unexpected error: %v", err)
+ }
+ var records []dns.RR
+ for rrs := range ch {
+ records = append(records, rrs...)
+ }
+
+ expect := []dns.RR{}
+ for _, tc := range append(tests, testsApex...) {
+ if tc.Rcode != dns.RcodeSuccess {
+ continue
+ }
+
+ for _, ans := range tc.Answer {
+ // Exclude wildcard test cases
+ if strings.Contains(ans.Header().Name, "*") {
+ continue
+ }
+
+ // Exclude TXT records
+ if ans.Header().Rrtype == dns.TypeTXT {
+ continue
+ }
+ expect = append(expect, ans)
+ }
+ }
+
+ diff := difference(expect, records)
+ if len(diff) != 0 {
+ t.Errorf("Got back %d records that do not exist in test cases, should be 0:", len(diff))
+ for _, rec := range diff {
+ t.Errorf("%+v", rec)
+ }
+ }
+
+ diff = difference(records, expect)
+ if len(diff) != 0 {
+ t.Errorf("Result is missing %d records, should be 0:", len(diff))
+ for _, rec := range diff {
+ t.Errorf("%+v", rec)
+ }
+ }
+
+}
+
+func TestTransferIXFR(t *testing.T) {
+ k := kubernetes.New([]string{"cluster.local."})
+ k.Namespaces = map[string]struct{}{"testns": {}}
+ k.APIConn = &external{}
+
+ e := New()
+ e.Zones = []string{"example.com."}
+ e.externalFunc = k.External
+ e.externalAddrFunc = externalAddress // internal test function
+ e.externalSerialFunc = externalSerial // internal test function
+ e.externalServicesFunc = k.ExternalServices
+
+ ch, err := e.Transfer("example.com.", externalSerial("example.com."))
+
+ if err != nil {
+ t.Fatalf("Unexpected error: %v", err)
+ }
+ var records []dns.RR
+ for rrs := range ch {
+ records = append(records, rrs...)
+ }
+
+ expect := []dns.RR{
+ test.SOA("example.com. 5 IN SOA ns1.dns.example.com. hostmaster.dns.example.com. 1499347823 7200 1800 86400 5"),
+ }
+
+ diff := difference(expect, records)
+ if len(diff) != 0 {
+ t.Errorf("Got back %d records that do not exist in test cases, should be 0:", len(diff))
+ for _, rec := range diff {
+ t.Errorf("%+v", rec)
+ }
+ }
+
+ diff = difference(records, expect)
+ if len(diff) != 0 {
+ t.Errorf("Result is missing %d records, should be 0:", len(diff))
+ for _, rec := range diff {
+ t.Errorf("%+v", rec)
+ }
+ }
+
+}
+
+// difference shows what we're missing when comparing two RR slices
+func difference(testRRs []dns.RR, gotRRs []dns.RR) []dns.RR {
+ expectedRRs := map[string]struct{}{}
+ for _, rr := range testRRs {
+ expectedRRs[rr.String()] = struct{}{}
+ }
+
+ foundRRs := []dns.RR{}
+ for _, rr := range gotRRs {
+ if _, ok := expectedRRs[rr.String()]; !ok {
+ foundRRs = append(foundRRs, rr)
+ }
+ }
+ return foundRRs
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-08-04 09:19:34 +0000