Allow to mark internal network as external

README.md

@@ -294,6 +294,7 @@ Environment Variable | Default | Description
 `LINODE_INSTANCE_CACHE_TTL` | `15` | Default timeout of instance cache in seconds
 `LINODE_ROUTES_CACHE_TTL_SECONDS` | `60` | Default timeout of route cache in seconds
 `LINODE_REQUEST_TIMEOUT_SECONDS` | `120` | Default timeout in seconds for http requests to linode API
+`LINODE_EXTERNAL_SUBNET` | | Mark private network as external. Example - `172.24.0.0/16`
 
 ## Generating a Manifest for Deployment
 Use the script located at `./deploy/generate-manifest.sh` to generate a self-contained deployment manifest for the Linode CCM. Two arguments are required.

cloud/linode/cloud.go

@@ -3,6 +3,7 @@ package linode
 import (
 	"fmt"
 	"io"
+	"net"
 	"os"
 	"strconv"
 	"sync"
@@ -37,6 +38,7 @@ var Options struct {
 	VPCName               string
 	LoadBalancerType      string
 	BGPNodeSelector       string
+	LinodeExternalNetwork *net.IPNet
 }
 
 // vpcDetails is set when VPCName options flag is set.

cloud/linode/common.go

@@ -2,6 +2,7 @@ package linode
 
 import (
 	"fmt"
+	"net"
 	"strconv"
 	"strings"
 
@@ -42,3 +43,11 @@ func IgnoreLinodeAPIError(err error, code int) error {
 
 	return err
 }
+
+func isPrivate(ip *net.IP) bool {
+	if Options.LinodeExternalNetwork == nil {
+		return ip.IsPrivate()
+	}
+
+	return ip.IsPrivate() && !Options.LinodeExternalNetwork.Contains(*ip)
+}

cloud/linode/instances.go

@@ -49,7 +49,7 @@ func (nc *nodeCache) getInstanceAddresses(instance linodego.Instance, vpcips []s
 
 	for _, ip := range instance.IPv4 {
 		ipType := v1.NodeExternalIP
-		if ip.IsPrivate() {
+		if isPrivate(ip) {
 			ipType = v1.NodeInternalIP
 		}
 		ips = append(ips, nodeIP{ip: ip.String(), ipType: ipType})
@@ -155,7 +155,7 @@ func (i *instances) linodeByIP(kNode *v1.Node) (*linodego.Instance, error) {
 	}
 	for _, node := range i.nodeCache.nodes {
 		for _, nodeIP := range node.instance.IPv4 {
-			if !nodeIP.IsPrivate() && slices.Contains(kNodeAddresses, nodeIP.String()) {
+			if !isPrivate(nodeIP) && slices.Contains(kNodeAddresses, nodeIP.String()) {
 				return node.instance, nil
 			}
 		}

cloud/linode/instances_test.go

@@ -146,52 +146,67 @@ func TestMetadataRetrieval(t *testing.T) {
 		name            string
 		inputIPv4s      []string
 		inputIPv6       string
+		externalNetwork string
 		outputAddresses []v1.NodeAddress
 		expectedErr     error
 	}{
-		{"no IPs", nil, "", nil, instanceNoIPAddressesError{192910}},
+		{"no IPs", nil, "", "", nil, instanceNoIPAddressesError{192910}},
 		{
 			"one public, one private",
 			[]string{"32.74.121.25", "192.168.121.42"},
 			"",
+			"",
 			[]v1.NodeAddress{{Type: v1.NodeExternalIP, Address: "32.74.121.25"}, {Type: v1.NodeInternalIP, Address: "192.168.121.42"}},
 			nil,
 		},
 		{
 			"one public ipv4, one public ipv6",
 			[]string{"32.74.121.25"},
 			"2600:3c06::f03c:94ff:fe1e:e072",
+			"",
 			[]v1.NodeAddress{{Type: v1.NodeExternalIP, Address: "32.74.121.25"}, {Type: v1.NodeExternalIP, Address: "2600:3c06::f03c:94ff:fe1e:e072"}},
 			nil,
 		},
 		{
 			"one public, no private",
 			[]string{"32.74.121.25"},
 			"",
+			"",
 			[]v1.NodeAddress{{Type: v1.NodeExternalIP, Address: "32.74.121.25"}},
 			nil,
 		},
 		{
 			"one private, no public",
 			[]string{"192.168.121.42"},
 			"",
+			"",
 			[]v1.NodeAddress{{Type: v1.NodeInternalIP, Address: "192.168.121.42"}},
 			nil,
 		},
 		{
 			"two public addresses",
 			[]string{"32.74.121.25", "32.74.121.22"},
 			"",
+			"",
 			[]v1.NodeAddress{{Type: v1.NodeExternalIP, Address: "32.74.121.25"}, {Type: v1.NodeExternalIP, Address: "32.74.121.22"}},
 			nil,
 		},
 		{
 			"two private addresses",
 			[]string{"192.168.121.42", "10.0.2.15"},
 			"",
+			"",
 			[]v1.NodeAddress{{Type: v1.NodeInternalIP, Address: "192.168.121.42"}, {Type: v1.NodeInternalIP, Address: "10.0.2.15"}},
 			nil,
 		},
+		{
+			"two private addresses - one in network marked as external",
+			[]string{"192.168.121.42", "10.0.2.15"},
+			"",
+			"10.0.2.0/16",
+			[]v1.NodeAddress{{Type: v1.NodeInternalIP, Address: "192.168.121.42"}, {Type: v1.NodeExternalIP, Address: "10.0.2.15"}},
+			nil,
+		},
 	}
 
 	for _, test := range ipTests {
@@ -201,7 +216,11 @@ func TestMetadataRetrieval(t *testing.T) {
 			name := "my-instance"
 			providerID := providerIDPrefix + strconv.Itoa(id)
 			node := nodeWithProviderID(providerID)
-
+			if test.externalNetwork == "" {
+				Options.LinodeExternalNetwork = nil
+			} else {
+				_, Options.LinodeExternalNetwork, _ = net.ParseCIDR(test.externalNetwork)
+			}
 			ips := make([]*net.IP, 0, len(test.inputIPv4s))
 			for _, ip := range test.inputIPv4s {
 				parsed := net.ParseIP(ip)

cloud/linode/node_controller.go

@@ -172,7 +172,7 @@
 	// supports other subnets with nodebalancer, this logic needs to be updated.
 	// https://www.linode.com/docs/api/linode-instances/#linode-view
 	for _, addr := range linode.IPv4 {
-		if addr.IsPrivate() {
+		if isPrivate(addr) {
 			expectedPrivateIP = addr.String()
 			break
 		}

main.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"net"
 	"os"
 
 	"k8s.io/component-base/logs"
@@ -25,9 +26,10 @@ import (
 )
 
 const (
-	sentryDSNVariable         = "SENTRY_DSN"
-	sentryEnvironmentVariable = "SENTRY_ENVIRONMENT"
-	sentryReleaseVariable     = "SENTRY_RELEASE"
+	sentryDSNVariable            = "SENTRY_DSN"
+	sentryEnvironmentVariable    = "SENTRY_ENVIRONMENT"
+	sentryReleaseVariable        = "SENTRY_RELEASE"
+	linodeExternalSubnetVariable = "LINODE_EXTERNAL_SUBNET"
 )
 
 func initializeSentry() {
@@ -114,6 +116,17 @@ func main() {
 		os.Exit(1)
 	}
 
+	if externalSubnet, ok := os.LookupEnv(linodeExternalSubnetVariable); ok && externalSubnet != "" {
+		_, network, err := net.ParseCIDR(externalSubnet)
+		if err != nil {
+			msg := fmt.Sprintf("Unable to parse %s as network subnet: %v", externalSubnet, err)
+			sentry.CaptureError(ctx, fmt.Errorf(msg))
+			fmt.Fprintf(os.Stderr, "%v\n", msg)
+			os.Exit(1)
+		}
+		linode.Options.LinodeExternalNetwork = network
+	}
+
 	pflag.CommandLine.SetNormalizeFunc(utilflag.WordSepNormalizeFunc)
 	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)