Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

podIPs order match node IP family preference (Downward API) #103307

Merged
merged 1 commit into from Jul 7, 2021
Merged

podIPs order match node IP family preference (Downward API) #103307

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
58 changes: 41 additions & 17 deletions pkg/kubelet/kubelet_pods.go
View file
Open in desktop
Expand Up @@ -809,6 +809,13 @@ func (kl *Kubelet) podFieldSelectorRuntimeValue(fs *v1.ObjectFieldSelector, pod
if err != nil {
return "", err
}

// make podIPs order match node IP family preference #97979
podIPs = kl.sortPodIPs(podIPs)
if len(podIPs) > 0 {
podIP = podIPs[0]
}

switch internalFieldPath {
case "spec.nodeName":
return pod.Spec.NodeName, nil
Expand Down Expand Up @@ -1570,16 +1577,14 @@ func (kl *Kubelet) generateAPIPodStatus(pod *v1.Pod, podStatus *kubecontainer.Po
return *s
}

// convertStatusToAPIStatus creates an api PodStatus for the given pod from
// the given internal pod status. It is purely transformative and does not
// alter the kubelet state at all.
func (kl *Kubelet) convertStatusToAPIStatus(pod *v1.Pod, podStatus *kubecontainer.PodStatus) *v1.PodStatus {
var apiPodStatus v1.PodStatus

// The runtime pod status may have an arbitrary number of IPs, in an arbitrary
// order. Pick out the first returned IP of the same IP family as the node IP
// first, followed by the first IP of the opposite IP family (if any).
podIPs := make([]v1.PodIP, 0, len(podStatus.IPs))
// sortPodIPs return the PodIPs sorted and truncated by the cluster IP family preference.
// The runtime pod status may have an arbitrary number of IPs, in an arbitrary order.
// PodIPs are obtained by: func (m *kubeGenericRuntimeManager) determinePodSandboxIPs()
// Pick out the first returned IP of the same IP family as the node IP
// first, followed by the first IP of the opposite IP family (if any)
// and use them for the Pod.Status.PodIPs and the Downward API environment variables
func (kl *Kubelet) sortPodIPs(podIPs []string) []string {
ips := make([]string, 0, 2)
var validPrimaryIP, validSecondaryIP func(ip string) bool
if len(kl.nodeIPs) == 0 || utilnet.IsIPv4(kl.nodeIPs[0]) {
validPrimaryIP = utilnet.IsIPv4String
Expand All @@ -1588,21 +1593,40 @@ func (kl *Kubelet) convertStatusToAPIStatus(pod *v1.Pod, podStatus *kubecontaine
validPrimaryIP = utilnet.IsIPv6String
validSecondaryIP = utilnet.IsIPv4String
}
for _, ip := range podStatus.IPs {
for _, ip := range podIPs {
if validPrimaryIP(ip) {
podIPs = append(podIPs, v1.PodIP{IP: ip})
ips = append(ips, ip)
break
}
}
for _, ip := range podStatus.IPs {
for _, ip := range podIPs {
if validSecondaryIP(ip) {
podIPs = append(podIPs, v1.PodIP{IP: ip})
ips = append(ips, ip)
break
}
}
apiPodStatus.PodIPs = podIPs
if len(podIPs) > 0 {
apiPodStatus.PodIP = podIPs[0].IP
return ips
}

// convertStatusToAPIStatus creates an api PodStatus for the given pod from
// the given internal pod status. It is purely transformative and does not
// alter the kubelet state at all.
func (kl *Kubelet) convertStatusToAPIStatus(pod *v1.Pod, podStatus *kubecontainer.PodStatus) *v1.PodStatus {
var apiPodStatus v1.PodStatus

// copy pod status IPs to avoid race conditions with PodStatus #102806
podIPs := make([]string, len(podStatus.IPs))
thockin marked this conversation as resolved.
Show resolved Hide resolved
for j, ip := range podStatus.IPs {
podIPs[j] = ip
}

// make podIPs order match node IP family preference #97979
podIPs = kl.sortPodIPs(podIPs)
Copy link
Member Author

@aojea aojea Jul 6, 2021 •
edited

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

is there some subtle golang thing that disallow this?

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I don't know - is something not working?

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

it does work, I just pass the slice as argument and override the same variable with the output, I think is fine, but I just wanted to double check

for _, ip := range podIPs {
apiPodStatus.PodIPs = append(apiPodStatus.PodIPs, v1.PodIP{IP: ip})
}
if len(apiPodStatus.PodIPs) > 0 {
apiPodStatus.PodIP = apiPodStatus.PodIPs[0].IP
}

// set status for Pods created on versions of kube older than 1.6
Expand Down
217 changes: 214 additions & 3 deletions pkg/kubelet/kubelet_pods_test.go
View file
Open in desktop
Expand Up @@ -461,6 +461,7 @@ func TestMakeEnvironmentVariables(t *testing.T) {
unsyncedServices bool // whether the services should NOT be synced
configMap *v1.ConfigMap // an optional ConfigMap to pull from
secret *v1.Secret // an optional Secret to pull from
podIPs []string // the pod IPs
expectedEnvs []kubecontainer.EnvVar // a set of expected environment vars
expectedError bool // does the test fail
expectedEvent string // does the test emit an event
Expand Down Expand Up @@ -766,6 +767,7 @@ func TestMakeEnvironmentVariables(t *testing.T) {
},
},
},
podIPs: []string{"1.2.3.4", "fd00::6"},
masterServiceNs: "nothing",
nilLister: true,
expectedEnvs: []kubecontainer.EnvVar{
Expand All @@ -778,6 +780,94 @@ func TestMakeEnvironmentVariables(t *testing.T) {
{Name: "HOST_IP", Value: testKubeletHostIP},
},
},
{
name: "downward api pod ips reverse order",
ns: "downward-api",
enableServiceLinks: &falseValue,
container: &v1.Container{
Env: []v1.EnvVar{
{
Name: "POD_IP",
ValueFrom: &v1.EnvVarSource{
FieldRef: &v1.ObjectFieldSelector{
APIVersion: "v1",
FieldPath: "status.podIP",
},
},
},
{
Name: "POD_IPS",
ValueFrom: &v1.EnvVarSource{
FieldRef: &v1.ObjectFieldSelector{
APIVersion: "v1",
FieldPath: "status.podIPs",
},
},
},
{
Name: "HOST_IP",
ValueFrom: &v1.EnvVarSource{
FieldRef: &v1.ObjectFieldSelector{
APIVersion: "v1",
FieldPath: "status.hostIP",
},
},
},
},
},
podIPs: []string{"fd00::6", "1.2.3.4"},
masterServiceNs: "nothing",
nilLister: true,
expectedEnvs: []kubecontainer.EnvVar{
{Name: "POD_IP", Value: "1.2.3.4"},
{Name: "POD_IPS", Value: "1.2.3.4,fd00::6"},
{Name: "HOST_IP", Value: testKubeletHostIP},
},
},
{
name: "downward api pod ips multiple ips",
ns: "downward-api",
enableServiceLinks: &falseValue,
container: &v1.Container{
Env: []v1.EnvVar{
{
Name: "POD_IP",
ValueFrom: &v1.EnvVarSource{
FieldRef: &v1.ObjectFieldSelector{
APIVersion: "v1",
FieldPath: "status.podIP",
},
},
},
{
Name: "POD_IPS",
ValueFrom: &v1.EnvVarSource{
FieldRef: &v1.ObjectFieldSelector{
APIVersion: "v1",
FieldPath: "status.podIPs",
},
},
},
{
Name: "HOST_IP",
ValueFrom: &v1.EnvVarSource{
FieldRef: &v1.ObjectFieldSelector{
APIVersion: "v1",
FieldPath: "status.hostIP",
},
},
},
},
},
podIPs: []string{"1.2.3.4", "192.168.1.1.", "fd00::6"},
masterServiceNs: "nothing",
nilLister: true,
expectedEnvs: []kubecontainer.EnvVar{
{Name: "POD_IP", Value: "1.2.3.4"},
{Name: "POD_IPS", Value: "1.2.3.4,fd00::6"},
{Name: "HOST_IP", Value: testKubeletHostIP},
},
},
{
name: "env expansion",
ns: "test1",
Expand Down Expand Up @@ -1685,13 +1775,15 @@ func TestMakeEnvironmentVariables(t *testing.T) {
EnableServiceLinks: tc.enableServiceLinks,
},
}
podIP := "1.2.3.4"
podIPs := []string{"1.2.3.4,fd00::6"}
podIP := ""
if len(tc.podIPs) > 0 {
podIP = tc.podIPs[0]
}
if tc.staticPod {
testPod.Annotations[kubetypes.ConfigSourceAnnotationKey] = "file"
}

result, err := kl.makeEnvironmentVariables(testPod, tc.container, podIP, podIPs)
result, err := kl.makeEnvironmentVariables(testPod, tc.container, podIP, tc.podIPs)
select {
case e := <-fakeRecorder.Events:
assert.Equal(t, tc.expectedEvent, e)
Expand Down Expand Up @@ -2837,6 +2929,33 @@ func TestGenerateAPIPodStatusHostNetworkPodIPs(t *testing.T) {
{IP: "192.168.0.1"},
},
},
{
name: "CRI dual-stack PodIPs override NodeAddresses",
nodeAddresses: []v1.NodeAddress{
{Type: v1.NodeInternalIP, Address: "10.0.0.1"},
{Type: v1.NodeInternalIP, Address: "fd01::1234"},
},
dualStack: true,
criPodIPs: []string{"192.168.0.1", "2001:db8::2"},
podIPs: []v1.PodIP{
{IP: "192.168.0.1"},
{IP: "2001:db8::2"},
},
},
{
// by default the cluster prefers IPv4
name: "CRI dual-stack PodIPs override NodeAddresses prefer IPv4",
nodeAddresses: []v1.NodeAddress{
{Type: v1.NodeInternalIP, Address: "10.0.0.1"},
{Type: v1.NodeInternalIP, Address: "fd01::1234"},
},
dualStack: true,
criPodIPs: []string{"2001:db8::2", "192.168.0.1"},
podIPs: []v1.PodIP{
{IP: "192.168.0.1"},
{IP: "2001:db8::2"},
},
},
}

for _, tc := range testcases {
Expand Down Expand Up @@ -3009,3 +3128,95 @@ func TestGenerateAPIPodStatusPodIPs(t *testing.T) {
})
}
}

func TestSortPodIPs(t *testing.T) {
testcases := []struct {
name string
nodeIP string
podIPs []string
expectedIPs []string
}{
{
name: "Simple",
nodeIP: "",
podIPs: []string{"10.0.0.1"},
expectedIPs: []string{"10.0.0.1"},
},
{
name: "Dual-stack",
nodeIP: "",
podIPs: []string{"10.0.0.1", "fd01::1234"},
expectedIPs: []string{"10.0.0.1", "fd01::1234"},
},
{
name: "Dual-stack with explicit node IP",
nodeIP: "192.168.1.1",
podIPs: []string{"10.0.0.1", "fd01::1234"},
expectedIPs: []string{"10.0.0.1", "fd01::1234"},
},
{
name: "Dual-stack with CRI returning wrong family first",
nodeIP: "",
podIPs: []string{"fd01::1234", "10.0.0.1"},
expectedIPs: []string{"10.0.0.1", "fd01::1234"},
},
{
name: "Dual-stack with explicit node IP with CRI returning wrong family first",
nodeIP: "192.168.1.1",
podIPs: []string{"fd01::1234", "10.0.0.1"},
expectedIPs: []string{"10.0.0.1", "fd01::1234"},
},
{
name: "Dual-stack with IPv6 node IP",
nodeIP: "fd00::5678",
podIPs: []string{"10.0.0.1", "fd01::1234"},
expectedIPs: []string{"fd01::1234", "10.0.0.1"},
},
{
name: "Dual-stack with IPv6 node IP, other CRI order",
nodeIP: "fd00::5678",
podIPs: []string{"fd01::1234", "10.0.0.1"},
expectedIPs: []string{"fd01::1234", "10.0.0.1"},
},
{
name: "No Pod IP matching Node IP",
nodeIP: "fd00::5678",
podIPs: []string{"10.0.0.1"},
expectedIPs: []string{"10.0.0.1"},
},
{
name: "No Pod IP matching (unspecified) Node IP",
nodeIP: "",
podIPs: []string{"fd01::1234"},
expectedIPs: []string{"fd01::1234"},
},
{
name: "Multiple IPv4 IPs",
nodeIP: "",
podIPs: []string{"10.0.0.1", "10.0.0.2", "10.0.0.3"},
expectedIPs: []string{"10.0.0.1"},
},
{
name: "Multiple Dual-Stack IPs",
nodeIP: "",
podIPs: []string{"10.0.0.1", "10.0.0.2", "fd01::1234", "10.0.0.3", "fd01::5678"},
expectedIPs: []string{"10.0.0.1", "fd01::1234"},
},
}

for _, tc := range testcases {
t.Run(tc.name, func(t *testing.T) {
testKubelet := newTestKubelet(t, false /* controllerAttachDetachEnabled */)
defer testKubelet.Cleanup()
kl := testKubelet.kubelet
if tc.nodeIP != "" {
kl.nodeIPs = []net.IP{net.ParseIP(tc.nodeIP)}
}

podIPs := kl.sortPodIPs(tc.podIPs)
if !reflect.DeepEqual(podIPs, tc.expectedIPs) {
t.Fatalf("Expected PodIPs %#v, got %#v", tc.expectedIPs, podIPs)
}
})
}
}