Merge pull request #56955 from feiskyer/scrub-dns

Automatic merge from submit-queue (batch tested with PRs 56997, 57008, 56984, 56975, 56955). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Remove unused ScrubDNS interface from cloudprovider

**What this PR does / why we need it**:

DNS scrubber from kubelet has been removed in #36785 and cloudprovider's `ScrubDNS()` interface is not used anywhere.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #56953.

**Special notes for your reviewer**:

**Release note**:

```release-note
Remove ScrubDNS interface from cloudprovider.
```

pkg/cloudprovider/cloud.go

@@ -44,8 +44,6 @@ type Interface interface {
 	Routes() (Routes, bool)
 	// ProviderName returns the cloud provider ID.
 	ProviderName() string
-	// ScrubDNS provides an opportunity for cloud-provider-specific code to process DNS settings for pods.
-	ScrubDNS(nameservers, searches []string) (nsOut, srchOut []string)
 	// HasClusterID returns true if a ClusterID is required and set
 	HasClusterID() bool
 }

pkg/cloudprovider/providers/aws/aws.go

@@ -1135,11 +1135,6 @@ func (c *Cloud) ProviderName() string {
 	return ProviderName
 }
 
-// ScrubDNS filters DNS settings for pods.
-func (c *Cloud) ScrubDNS(nameservers, searches []string) (nsOut, srchOut []string) {
-	return nameservers, searches
-}
-
 // LoadBalancer returns an implementation of LoadBalancer for Amazon Web Services.
 func (c *Cloud) LoadBalancer() (cloudprovider.LoadBalancer, bool) {
 	return c, true

pkg/cloudprovider/providers/azure/azure.go

@@ -489,11 +489,6 @@ func (az *Cloud) Routes() (cloudprovider.Routes, bool) {
 	return az, true
 }
 
-// ScrubDNS provides an opportunity for cloud-provider-specific code to process DNS settings for pods.
-func (az *Cloud) ScrubDNS(nameservers, searches []string) (nsOut, srchOut []string) {
-	return nameservers, searches
-}
-
 // HasClusterID returns true if the cluster has a clusterID
 func (az *Cloud) HasClusterID() bool {
 	return true

pkg/cloudprovider/providers/cloudstack/cloudstack.go

@@ -181,11 +181,6 @@ func (cs *CSCloud) ProviderName() string {
 	return ProviderName
 }
 
-// ScrubDNS filters DNS settings for pods.
-func (cs *CSCloud) ScrubDNS(nameservers, searches []string) (nsOut, srchOut []string) {
-	return nameservers, searches
-}
-
 // HasClusterID returns true if the cluster has a clusterID
 func (cs *CSCloud) HasClusterID() bool {
 	return true

pkg/cloudprovider/providers/fake/fake.go

@@ -110,11 +110,6 @@ func (f *FakeCloud) ProviderName() string {
 	return f.Provider
 }
 
-// ScrubDNS filters DNS settings for pods.
-func (f *FakeCloud) ScrubDNS(nameservers, searches []string) (nsOut, srchOut []string) {
-	return nameservers, searches
-}
-
 // HasClusterID returns true if the cluster has a clusterID
 func (f *FakeCloud) HasClusterID() bool {
 	return true

pkg/cloudprovider/providers/gce/gce.go

@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-	"regexp"
 	"runtime"
 	"strconv"
 	"strings"
@@ -667,20 +666,6 @@ func (gce *GCECloud) updateNodeZones(prevNode, newNode *v1.Node) {
 	}
 }
 
-// Known-useless DNS search path.
-var uselessDNSSearchRE = regexp.MustCompile(`^[0-9]+.google.internal.$`)
-
-// ScrubDNS filters DNS settings for pods.
-func (gce *GCECloud) ScrubDNS(nameservers, searches []string) (nsOut, srchOut []string) {
-	// GCE has too many search paths by default. Filter the ones we know are useless.
-	for _, s := range searches {
-		if !uselessDNSSearchRE.MatchString(s) {
-			srchOut = append(srchOut, s)
-		}
-	}
-	return nameservers, srchOut
-}
-
 // HasClusterID returns true if the cluster has a clusterID
 func (gce *GCECloud) HasClusterID() bool {
 	return true

pkg/cloudprovider/providers/gce/gce_test.go

@@ -175,42 +175,6 @@ func TestComparingHostURLs(t *testing.T) {
 	}
 }
 
-func TestScrubDNS(t *testing.T) {
-	tcs := []struct {
-		nameserversIn  []string
-		searchesIn     []string
-		nameserversOut []string
-		searchesOut    []string
-	}{
-		{
-			nameserversIn:  []string{"1.2.3.4", "5.6.7.8"},
-			nameserversOut: []string{"1.2.3.4", "5.6.7.8"},
-		},
-		{
-			searchesIn:  []string{"c.prj.internal.", "12345678910.google.internal.", "google.internal."},
-			searchesOut: []string{"c.prj.internal.", "google.internal."},
-		},
-		{
-			searchesIn:  []string{"c.prj.internal.", "12345678910.google.internal.", "zone.c.prj.internal.", "google.internal."},
-			searchesOut: []string{"c.prj.internal.", "zone.c.prj.internal.", "google.internal."},
-		},
-		{
-			searchesIn:  []string{"c.prj.internal.", "12345678910.google.internal.", "zone.c.prj.internal.", "google.internal.", "unexpected"},
-			searchesOut: []string{"c.prj.internal.", "zone.c.prj.internal.", "google.internal.", "unexpected"},
-		},
-	}
-	gce := &GCECloud{}
-	for i := range tcs {
-		n, s := gce.ScrubDNS(tcs[i].nameserversIn, tcs[i].searchesIn)
-		if !reflect.DeepEqual(n, tcs[i].nameserversOut) {
-			t.Errorf("Expected %v, got %v", tcs[i].nameserversOut, n)
-		}
-		if !reflect.DeepEqual(s, tcs[i].searchesOut) {
-			t.Errorf("Expected %v, got %v", tcs[i].searchesOut, s)
-		}
-	}
-}
-
 func TestSplitProviderID(t *testing.T) {
 	providers := []struct {
 		providerID string

pkg/cloudprovider/providers/openstack/openstack.go

@@ -486,11 +486,6 @@ func (os *OpenStack) ProviderName() string {
 	return ProviderName
 }
 
-// ScrubDNS filters DNS settings for pods.
-func (os *OpenStack) ScrubDNS(nameServers, searches []string) ([]string, []string) {
-	return nameServers, searches
-}
-
 // HasClusterID returns true if the cluster has a clusterID
 func (os *OpenStack) HasClusterID() bool {
 	return true

pkg/cloudprovider/providers/ovirt/ovirt.go

@@ -128,11 +128,6 @@ func (v *OVirtCloud) ProviderName() string {
 	return ProviderName
 }
 
-// ScrubDNS filters DNS settings for pods.
-func (v *OVirtCloud) ScrubDNS(nameservers, searches []string) (nsOut, srchOut []string) {
-	return nameservers, searches
-}
-
 // HasClusterID returns true if the cluster has a clusterID
 func (v *OVirtCloud) HasClusterID() bool {
 	return true

pkg/cloudprovider/providers/photon/photon.go

@@ -546,11 +546,6 @@ func (pc *PCCloud) Routes() (cloudprovider.Routes, bool) {
 	return nil, false
 }
 
-// ScrubDNS filters DNS settings for pods.
-func (pc *PCCloud) ScrubDNS(nameservers, searches []string) (nsOut, srchOut []string) {
-	return nameservers, searches
-}
-
 // HasClusterID returns true if the cluster has a clusterID
 func (pc *PCCloud) HasClusterID() bool {
 	return true

pkg/cloudprovider/providers/vsphere/vsphere.go

@@ -690,11 +690,6 @@ func (vs *VSphere) Routes() (cloudprovider.Routes, bool) {
 	return nil, false
 }
 
-// ScrubDNS filters DNS settings for pods.
-func (vs *VSphere) ScrubDNS(nameservers, searches []string) (nsOut, srchOut []string) {
-	return nameservers, searches
-}
-
 // AttachDisk attaches given virtual disk volume to the compute running kubelet.
 func (vs *VSphere) AttachDisk(vmDiskPath string, storagePolicyName string, nodeName k8stypes.NodeName) (diskUUID string, err error) {
 	attachDiskInternal := func(vmDiskPath string, storagePolicyName string, nodeName k8stypes.NodeName) (diskUUID string, err error) {