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feat: allow pod IPs even for non-hostNetwork pods
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but only for the internalHostnameAnnotationKey which doesn't use the node's IP anyway
tests validate this for annotations with:
- mixing pods in the host network with others that are not
- multiple comma separated annotations per Pod
- explicitly set targets
- IPv4 and IPv6
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@peterhoneder @raoulbhatia
peterhoneder authored and raoulbhatia committed Sep 27, 2024
1 parent 0928d52 commit f1424a2
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Showing 2 changed files with 118 additions and 42 deletions.
70 changes: 34 additions & 36 deletions source/pod.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,6 @@ import (

"sigs.k8s.io/external-dns/endpoint"

log "github.com/sirupsen/logrus"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/labels"
kubeinformers "k8s.io/client-go/informers"
Expand Down Expand Up @@ -84,13 +83,9 @@ func (ps *podSource) Endpoints(ctx context.Context) ([]*endpoint.Endpoint, error

endpointMap := make(map[endpoint.EndpointKey][]string)
for _, pod := range pods {
if !pod.Spec.HostNetwork {
log.Debugf("skipping pod %s. hostNetwork=false", pod.Name)
continue
}

targets := getTargetsFromTargetAnnotation(pod.Annotations)

// accept hostname annotations that point to the pod's IP, no matter if the pod spec uses the host network
if domainAnnotation, ok := pod.Annotations[internalHostnameAnnotationKey]; ok {
domainList := splitHostnameAnnotation(domainAnnotation)
for _, domain := range domainList {
Expand All @@ -104,43 +99,46 @@ func (ps *podSource) Endpoints(ctx context.Context) ([]*endpoint.Endpoint, error
}
}

if domainAnnotation, ok := pod.Annotations[hostnameAnnotationKey]; ok {
domainList := splitHostnameAnnotation(domainAnnotation)
for _, domain := range domainList {
if len(targets) == 0 {
node, _ := ps.nodeInformer.Lister().Get(pod.Spec.NodeName)
for _, address := range node.Status.Addresses {
recordType := suitableType(address.Address)
// IPv6 addresses are labeled as NodeInternalIP despite being usable externally as well.
if address.Type == corev1.NodeExternalIP || (address.Type == corev1.NodeInternalIP && recordType == endpoint.RecordTypeAAAA) {
addToEndpointMap(endpointMap, domain, recordType, address.Address)
// accept annotations that point to the node's external IP (or IPv6 NodeInternalIP) only for pods using the host network
if pod.Spec.HostNetwork {
if domainAnnotation, ok := pod.Annotations[hostnameAnnotationKey]; ok {
domainList := splitHostnameAnnotation(domainAnnotation)
for _, domain := range domainList {
if len(targets) == 0 {
node, _ := ps.nodeInformer.Lister().Get(pod.Spec.NodeName)
for _, address := range node.Status.Addresses {
recordType := suitableType(address.Address)
// IPv6 addresses are labeled as NodeInternalIP despite being usable externally as well.
if address.Type == corev1.NodeExternalIP || (address.Type == corev1.NodeInternalIP && recordType == endpoint.RecordTypeAAAA) {
addToEndpointMap(endpointMap, domain, recordType, address.Address)
}
}
} else {
for _, target := range targets {
addToEndpointMap(endpointMap, domain, suitableType(target), target)
}
}
} else {
for _, target := range targets {
addToEndpointMap(endpointMap, domain, suitableType(target), target)
}
}
}
}

if ps.compatibility == "kops-dns-controller" {
if domainAnnotation, ok := pod.Annotations[kopsDNSControllerInternalHostnameAnnotationKey]; ok {
domainList := splitHostnameAnnotation(domainAnnotation)
for _, domain := range domainList {
addToEndpointMap(endpointMap, domain, suitableType(pod.Status.PodIP), pod.Status.PodIP)
if ps.compatibility == "kops-dns-controller" {
if domainAnnotation, ok := pod.Annotations[kopsDNSControllerInternalHostnameAnnotationKey]; ok {
domainList := splitHostnameAnnotation(domainAnnotation)
for _, domain := range domainList {
addToEndpointMap(endpointMap, domain, suitableType(pod.Status.PodIP), pod.Status.PodIP)
}
}
}

if domainAnnotation, ok := pod.Annotations[kopsDNSControllerHostnameAnnotationKey]; ok {
domainList := splitHostnameAnnotation(domainAnnotation)
for _, domain := range domainList {
node, _ := ps.nodeInformer.Lister().Get(pod.Spec.NodeName)
for _, address := range node.Status.Addresses {
recordType := suitableType(address.Address)
// IPv6 addresses are labeled as NodeInternalIP despite being usable externally as well.
if address.Type == corev1.NodeExternalIP || (address.Type == corev1.NodeInternalIP && recordType == endpoint.RecordTypeAAAA) {
addToEndpointMap(endpointMap, domain, recordType, address.Address)
if domainAnnotation, ok := pod.Annotations[kopsDNSControllerHostnameAnnotationKey]; ok {
domainList := splitHostnameAnnotation(domainAnnotation)
for _, domain := range domainList {
node, _ := ps.nodeInformer.Lister().Get(pod.Spec.NodeName)
for _, address := range node.Status.Addresses {
recordType := suitableType(address.Address)
// IPv6 addresses are labeled as NodeInternalIP despite being usable externally as well.
if address.Type == corev1.NodeExternalIP || (address.Type == corev1.NodeInternalIP && recordType == endpoint.RecordTypeAAAA) {
addToEndpointMap(endpointMap, domain, recordType, address.Address)
}
}
}
}
Expand Down
90 changes: 84 additions & 6 deletions source/pod_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -178,6 +178,24 @@ func TestPodSource(t *testing.T) {
PodIP: "10.0.1.2",
},
},
// this pod must be ignored because it's not in the host network and kops requires this
{
ObjectMeta: metav1.ObjectMeta{
Name: "my-pod3",
Namespace: "kube-system",
Annotations: map[string]string{
kopsDNSControllerInternalHostnameAnnotationKey: "internal.a.foo.example.org",
kopsDNSControllerHostnameAnnotationKey: "a.foo.example.org",
},
},
Spec: corev1.PodSpec{
HostNetwork: false,
NodeName: "my-node2",
},
Status: corev1.PodStatus{
PodIP: "10.0.1.3",
},
},
},
},
{
Expand All @@ -186,7 +204,7 @@ func TestPodSource(t *testing.T) {
"",
[]*endpoint.Endpoint{
{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"2001:DB8::1", "2001:DB8::2"}, RecordType: endpoint.RecordTypeAAAA},
{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"2001:DB8::1", "2001:DB8::2"}, RecordType: endpoint.RecordTypeAAAA},
{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"2001:DB8::1", "2001:DB8::2", "2001:DB8::3"}, RecordType: endpoint.RecordTypeAAAA},
},
false,
[]*corev1.Node{
Expand Down Expand Up @@ -246,6 +264,24 @@ func TestPodSource(t *testing.T) {
PodIP: "2001:DB8::2",
},
},
// this pod's internal hostname annotation must not be ignored even though it's not in the host network
{
ObjectMeta: metav1.ObjectMeta{
Name: "my-pod3",
Namespace: "kube-system",
Annotations: map[string]string{
internalHostnameAnnotationKey: "internal.a.foo.example.org",
hostnameAnnotationKey: "a.foo.example.org",
},
},
Spec: corev1.PodSpec{
HostNetwork: false,
NodeName: "my-node2",
},
Status: corev1.PodStatus{
PodIP: "2001:DB8::3",
},
},
},
},
{
Expand Down Expand Up @@ -314,6 +350,24 @@ func TestPodSource(t *testing.T) {
PodIP: "2001:DB8::2",
},
},
// this pod must be ignored because it's not in the host network and kops requires this (no matter the type of hostname annotation)
{
ObjectMeta: metav1.ObjectMeta{
Name: "my-pod3",
Namespace: "kube-system",
Annotations: map[string]string{
kopsDNSControllerInternalHostnameAnnotationKey: "internal.a.foo.example.org",
kopsDNSControllerHostnameAnnotationKey: "a.foo.example.org",
},
},
Spec: corev1.PodSpec{
HostNetwork: false,
NodeName: "my-node2",
},
Status: corev1.PodStatus{
PodIP: "2001:DB8::3",
},
},
},
},
{
Expand All @@ -322,7 +376,7 @@ func TestPodSource(t *testing.T) {
"",
[]*endpoint.Endpoint{
{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"208.1.2.1", "208.1.2.2"}, RecordType: endpoint.RecordTypeA},
{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"208.1.2.1", "208.1.2.2"}, RecordType: endpoint.RecordTypeA},
{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"208.1.2.1", "208.1.2.2", "208.1.2.3"}, RecordType: endpoint.RecordTypeA},
},
false,
[]*corev1.Node{
Expand Down Expand Up @@ -386,6 +440,25 @@ func TestPodSource(t *testing.T) {
PodIP: "10.0.1.2",
},
},
// this pod's internal hostname annotation must not be ignored even though it's not in the host network (even when using a custom target annotation)
{
ObjectMeta: metav1.ObjectMeta{
Name: "my-pod3",
Namespace: "kube-system",
Annotations: map[string]string{
internalHostnameAnnotationKey: "internal.a.foo.example.org",
hostnameAnnotationKey: "a.foo.example.org",
targetAnnotationKey: "208.1.2.3",
},
},
Spec: corev1.PodSpec{
HostNetwork: false,
NodeName: "my-node2",
},
Status: corev1.PodStatus{
PodIP: "10.0.1.3",
},
},
},
},
{
Expand Down Expand Up @@ -459,12 +532,16 @@ func TestPodSource(t *testing.T) {
},
},
{
"pods with hostNetwore=false should be ignored",
"internal hostname annotations of pods with hostNetwore=false should still be added as valid records",
"",
"",
[]*endpoint.Endpoint{
{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"54.10.11.1"}, RecordType: endpoint.RecordTypeA},
{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"10.0.1.1"}, RecordType: endpoint.RecordTypeA},
{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"10.0.1.1", "100.0.1.2"}, RecordType: endpoint.RecordTypeA},
// this annotation is part of a comma separated hostname list in the annotation
{DNSName: "internal.b.foo.example.org", Targets: endpoint.Targets{"10.0.1.1"}, RecordType: endpoint.RecordTypeA},
// this annotation is part of a comma separated hostname list in the annotation
{DNSName: "internal.c.foo.example.org", Targets: endpoint.Targets{"100.0.1.2"}, RecordType: endpoint.RecordTypeA},
},
false,
[]*corev1.Node{
Expand All @@ -491,13 +568,14 @@ func TestPodSource(t *testing.T) {
},
},
},
// a mixed set of a host network pod and non host network pod should include both pod IPs of the internal hostname annotation in the endpoint
[]*corev1.Pod{
{
ObjectMeta: metav1.ObjectMeta{
Name: "my-pod1",
Namespace: "kube-system",
Annotations: map[string]string{
internalHostnameAnnotationKey: "internal.a.foo.example.org",
internalHostnameAnnotationKey: "internal.a.foo.example.org,internal.b.foo.example.org",
hostnameAnnotationKey: "a.foo.example.org",
},
},
Expand All @@ -514,7 +592,7 @@ func TestPodSource(t *testing.T) {
Name: "my-pod2",
Namespace: "kube-system",
Annotations: map[string]string{
internalHostnameAnnotationKey: "internal.a.foo.example.org",
internalHostnameAnnotationKey: "internal.a.foo.example.org,internal.c.foo.example.org",
hostnameAnnotationKey: "a.foo.example.org",
},
},
Expand Down

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