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fix kubernetes in-cluster CNAME lookup (#2040)

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fix #2038

Signed-off-by: bingshen.wbs <bingshen.wbs@alibaba-inc.com>
This commit is contained in:
Bingshen Wang 2018-08-25 20:53:41 +08:00 • committed by Chris O'Haver
parent 610bdc091d
commit 75f1b9c988
3 changed files with 50 additions and 27 deletions
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41
plugin/backend_lookup.go
View file

@ -40,24 +40,22 @@ func A(b ServiceBackend, zone string, state request.Request, previousRecords []d
if dnsutil.DuplicateCNAME(newRecord, previousRecords) {
continue
}
if dns.IsSubDomain(zone, dns.Fqdn(serv.Host)) {
state1 := state.NewWithQuestion(serv.Host, state.QType())
state1.Zone = zone
nextRecords, err := A(b, zone, state1, append(previousRecords, newRecord), opt)
state1 := state.NewWithQuestion(serv.Host, state.QType())
nextRecords, err := A(b, zone, state1, append(previousRecords, newRecord), opt)
if err == nil {
// Not only have we found something we should add the CNAME and the IP addresses.
if len(nextRecords) > 0 {
records = append(records, newRecord)
records = append(records, nextRecords...)
if err == nil {
// Not only have we found something we should add the CNAME and the IP addresses.
if len(nextRecords) > 0 {
records = append(records, newRecord)
records = append(records, nextRecords...)
}
}
continue
}
// This means we can not complete the CNAME, try to look else where.
target := newRecord.Target
if dns.IsSubDomain(zone, target) {
// We should already have found it
continue
}
// Lookup
m1, e1 := b.Lookup(state, target, state.QType())
if e1 != nil {
@ -110,19 +108,20 @@ func AAAA(b ServiceBackend, zone string, state request.Request, previousRecords
if dnsutil.DuplicateCNAME(newRecord, previousRecords) {
continue
}
if dns.IsSubDomain(zone, dns.Fqdn(serv.Host)) {
state1 := state.NewWithQuestion(serv.Host, state.QType())
state1.Zone = zone
nextRecords, err := AAAA(b, zone, state1, append(previousRecords, newRecord), opt)
state1 := state.NewWithQuestion(serv.Host, state.QType())
nextRecords, err := AAAA(b, zone, state1, append(previousRecords, newRecord), opt)
if err == nil {
// Not only have we found something we should add the CNAME and the IP addresses.
if len(nextRecords) > 0 {
records = append(records, newRecord)
records = append(records, nextRecords...)
if err == nil {
// Not only have we found something we should add the CNAME and the IP addresses.
if len(nextRecords) > 0 {
records = append(records, newRecord)
records = append(records, nextRecords...)
}
}
continue
}
// This means we can not complete the CNAME, try to look else where.
target := newRecord.Target
m1, e1 := b.Lookup(state, target, state.QType())

24
plugin/kubernetes/handler_test.go
View file

@ -183,6 +183,15 @@ var dnsTestCases = []test.Case{
test.CNAME("external.testns.svc.cluster.local. 5 IN CNAME ext.interwebs.test."),
},
},
// CNAME External To Internal Service
{
Qname: "external-to-service.testns.svc.cluster.local", Qtype: dns.TypeA,
Rcode: dns.RcodeSuccess,
Answer: []dns.RR{
test.CNAME("external-to-service.testns.svc.cluster.local. 5 IN CNAME svc1.testns.svc.cluster.local."),
test.A("svc1.testns.svc.cluster.local. 5 IN A 10.0.0.1"),
},
},
// AAAA Service (with an existing A record, but no AAAA record)
{
Qname: "svc1.testns.svc.cluster.local.", Qtype: dns.TypeAAAA,
@ -420,6 +429,21 @@ var svcIndex = map[string][]*api.Service{
Type: api.ServiceTypeExternalName,
},
}},
"external-to-service.testns": {{
ObjectMeta: meta.ObjectMeta{
Name: "external-to-service",
Namespace: "testns",
},
Spec: api.ServiceSpec{
ExternalName: "svc1.testns.svc.cluster.local.",
Ports: []api.ServicePort{{
Name: "http",
Protocol: "tcp",
Port: 80,
}},
Type: api.ServiceTypeExternalName,
},
}},
}
func (APIConnServeTest) SvcIndex(s string) []*api.Service {

12
plugin/kubernetes/parse_test.go
View file

@ -14,17 +14,17 @@ func TestParseRequest(t *testing.T) {
expected string // output from r.String()
}{
// valid SRV request
{"_http._tcp.webs.mynamespace.svc.inter.webs.test.", "http.tcp..webs.mynamespace.svc"},
{"_http._tcp.webs.mynamespace.svc.inter.webs.tests.", "http.tcp..webs.mynamespace.svc"},
// wildcard acceptance
{"*.any.*.any.svc.inter.webs.test.", "*.any..*.any.svc"},
{"*.any.*.any.svc.inter.webs.tests.", "*.any..*.any.svc"},
// A request of endpoint
{"1-2-3-4.webs.mynamespace.svc.inter.webs.test.", "*.*.1-2-3-4.webs.mynamespace.svc"},
{"1-2-3-4.webs.mynamespace.svc.inter.webs.tests.", "*.*.1-2-3-4.webs.mynamespace.svc"},
// bare zone
{"inter.webs.test.", "....."},
{"inter.webs.tests.", "....."},
// bare svc type
{"svc.inter.webs.test.", "....."},
{"svc.inter.webs.tests.", "....."},
// bare pod type
{"pod.inter.webs.test.", "....."},
{"pod.inter.webs.tests.", "....."},
}
for i, tc := range tests {
m := new(dns.Msg)