Report Additional POD IPs

Signed-off-by: Lantao Liu <lantaol@google.com>

pkg/config/config.go

@@ -87,8 +87,9 @@ type CniConfig struct {
 	NetworkPluginMaxConfNum int `toml:"max_conf_num" json:"maxConfNum"`
 	// NetworkPluginConfTemplate is the file path of golang template used to generate
 	// cni config.
-	// When it is set, containerd will get cidr from kubelet to replace {{.PodCIDR}} in
+	// When it is set, containerd will get cidr(s) from kubelet to replace {{.PodCIDR}},
-	// the template, and write the config into NetworkPluginConfDir.
+	// {{.PodCIDRRanges}} or {{.Routes}} in the template, and write the config into
+	// NetworkPluginConfDir.
 	// Ideally the cni config should be placed by system admin or cni daemon like calico,
 	// weaveworks etc. However, there are still users using kubenet
 	// (https://kubernetes.io/docs/concepts/cluster-administration/network-plugins/#kubenet)

pkg/server/sandbox_run.go

@@ -137,14 +137,14 @@ func (c *criService) RunPodSandbox(ctx context.Context, r *runtime.RunPodSandbox
 		// In this case however caching the IP will add a subtle performance enhancement by avoiding
 		// calls to network namespace of the pod to query the IP of the veth interface on every
 		// SandboxStatus request.
-		sandbox.IP, sandbox.CNIResult, err = c.setupPod(ctx, id, sandbox.NetNSPath, config)
+		sandbox.IP, sandbox.AdditionalIPs, sandbox.CNIResult, err = c.setupPodNetwork(ctx, id, sandbox.NetNSPath, config)
 		if err != nil {
 			return nil, errors.Wrapf(err, "failed to setup network for sandbox %q", id)
 		}
 		defer func() {
 			if retErr != nil {
 				// Teardown network if an error is returned.
-				if err := c.teardownPod(ctx, id, sandbox.NetNSPath, config); err != nil {
+				if err := c.teardownPodNetwork(ctx, id, sandbox.NetNSPath, config); err != nil {
 					log.G(ctx).WithError(err).Errorf("Failed to destroy network for sandbox %q", id)
 				}
 			}
@@ -302,31 +302,32 @@ func (c *criService) RunPodSandbox(ctx context.Context, r *runtime.RunPodSandbox
 	return &runtime.RunPodSandboxResponse{PodSandboxId: id}, nil
 }
 
-// setupPod setups up the network for a pod
+// setupPodNetwork setups up the network for a pod
-func (c *criService) setupPod(ctx context.Context, id string, path string, config *runtime.PodSandboxConfig) (string, *cni.CNIResult, error) {
+func (c *criService) setupPodNetwork(ctx context.Context, id string, path string, config *runtime.PodSandboxConfig) (string, []string, *cni.CNIResult, error) {
 	if c.netPlugin == nil {
-		return "", nil, errors.New("cni config not initialized")
+		return "", nil, nil, errors.New("cni config not initialized")
 	}
 
 	opts, err := cniNamespaceOpts(id, config)
 	if err != nil {
-		return "", nil, errors.Wrap(err, "get cni namespace options")
+		return "", nil, nil, errors.Wrap(err, "get cni namespace options")
 	}
 
 	result, err := c.netPlugin.Setup(ctx, id, path, opts...)
 	if err != nil {
-		return "", nil, err
+		return "", nil, nil, err
 	}
 	logDebugCNIResult(ctx, id, result)
 	// Check if the default interface has IP config
 	if configs, ok := result.Interfaces[defaultIfName]; ok && len(configs.IPConfigs) > 0 {
-		return selectPodIP(configs.IPConfigs), result, nil
+		ip, additionalIPs := selectPodIPs(configs.IPConfigs)
+		return ip, additionalIPs, result, nil
 	}
 	// If it comes here then the result was invalid so destroy the pod network and return error
-	if err := c.teardownPod(ctx, id, path, config); err != nil {
+	if err := c.teardownPodNetwork(ctx, id, path, config); err != nil {
 		log.G(ctx).WithError(err).Errorf("Failed to destroy network for sandbox %q", id)
 	}
-	return "", result, errors.Errorf("failed to find network info for sandbox %q", id)
+	return "", nil, result, errors.Errorf("failed to find network info for sandbox %q", id)
 }
 
 // cniNamespaceOpts get CNI namespace options from sandbox config.
@@ -426,14 +427,28 @@ func toCNIDNS(dns *runtime.DNSConfig) *cni.DNS {
 	}
 }
 
-// selectPodIP select an ip from the ip list. It prefers ipv4 more than ipv6.
+// selectPodIPs select an ip from the ip list. It prefers ipv4 more than ipv6
-func selectPodIP(ipConfigs []*cni.IPConfig) string {
+// and returns the additional ips
+// TODO(random-liu): Revisit the ip order in the ipv6 beta stage. (cri#1278)
+func selectPodIPs(ipConfigs []*cni.IPConfig) (string, []string) {
+	var (
+		additionalIPs []string
+		ip            string
+	)
 	for _, c := range ipConfigs {
-		if c.IP.To4() != nil {
+		if c.IP.To4() != nil && ip == "" {
-			return c.IP.String()
+			ip = c.IP.String()
+		} else {
+			additionalIPs = append(additionalIPs, c.IP.String())
 		}
 	}
-	return ipConfigs[0].IP.String()
+	if ip != "" {
+		return ip, additionalIPs
+	}
+	if len(ipConfigs) == 1 {
+		return additionalIPs[0], nil
+	}
+	return additionalIPs[0], additionalIPs[1:]
 }
 
 // untrustedWorkload returns true if the sandbox contains untrusted workload.

pkg/server/sandbox_run_test.go

@@ -247,15 +247,28 @@ func TestToCNIPortMappings(t *testing.T) {
 func TestSelectPodIP(t *testing.T) {
 	for desc, test := range map[string]struct {
 		ips                   []string
-		expected string
+		expectedIP            string
+		expectedAdditionalIPs []string
 	}{
 		"ipv4 should be picked even if ipv6 comes first": {
 			ips:                   []string{"2001:db8:85a3::8a2e:370:7334", "192.168.17.43"},
-			expected: "192.168.17.43",
+			expectedIP:            "192.168.17.43",
+			expectedAdditionalIPs: []string{"2001:db8:85a3::8a2e:370:7334"},
+		},
+		"ipv4 should be picked when there is only ipv4": {
+			ips:                   []string{"192.168.17.43"},
+			expectedIP:            "192.168.17.43",
+			expectedAdditionalIPs: nil,
 		},
 		"ipv6 should be picked when there is no ipv4": {
 			ips:                   []string{"2001:db8:85a3::8a2e:370:7334"},
-			expected: "2001:db8:85a3::8a2e:370:7334",
+			expectedIP:            "2001:db8:85a3::8a2e:370:7334",
+			expectedAdditionalIPs: nil,
+		},
+		"the first ipv4 should be picked when there are multiple ipv4": { // unlikely to happen
+			ips:                   []string{"2001:db8:85a3::8a2e:370:7334", "192.168.17.43", "2001:db8:85a3::8a2e:370:7335", "192.168.17.45"},
+			expectedIP:            "192.168.17.43",
+			expectedAdditionalIPs: []string{"2001:db8:85a3::8a2e:370:7334", "2001:db8:85a3::8a2e:370:7335", "192.168.17.45"},
 		},
 	} {
 		t.Logf("TestCase %q", desc)
@@ -265,7 +278,9 @@ func TestSelectPodIP(t *testing.T) {
 				IP: net.ParseIP(ip),
 			})
 		}
-		assert.Equal(t, test.expected, selectPodIP(ipConfigs))
+		ip, additionalIPs := selectPodIPs(ipConfigs)
+		assert.Equal(t, test.expectedIP, ip)
+		assert.Equal(t, test.expectedAdditionalIPs, additionalIPs)
 	}
 }
 

pkg/server/sandbox_status.go

@@ -38,11 +38,11 @@ func (c *criService) PodSandboxStatus(ctx context.Context, r *runtime.PodSandbox
 		return nil, errors.Wrap(err, "an error occurred when try to find sandbox")
 	}
 
-	ip, err := c.getIP(sandbox)
+	ip, additionalIPs, err := c.getIPs(sandbox)
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to get sandbox ip")
 	}
-	status := toCRISandboxStatus(sandbox.Metadata, sandbox.Status.Get(), ip)
+	status := toCRISandboxStatus(sandbox.Metadata, sandbox.Status.Get(), ip, additionalIPs)
 	if status.GetCreatedAt() == 0 {
 		// CRI doesn't allow CreatedAt == 0.
 		info, err := sandbox.Container.Info(ctx)
@@ -67,39 +67,46 @@ func (c *criService) PodSandboxStatus(ctx context.Context, r *runtime.PodSandbox
 	}, nil
 }
 
-func (c *criService) getIP(sandbox sandboxstore.Sandbox) (string, error) {
+func (c *criService) getIPs(sandbox sandboxstore.Sandbox) (string, []string, error) {
 	config := sandbox.Config
 
 	if goruntime.GOOS != "windows" &&
 		config.GetLinux().GetSecurityContext().GetNamespaceOptions().GetNetwork() == runtime.NamespaceMode_NODE {
 		// For sandboxes using the node network we are not
 		// responsible for reporting the IP.
-		return "", nil
+		return "", nil, nil
 	}
 
 	if closed, err := sandbox.NetNS.Closed(); err != nil {
-		return "", errors.Wrap(err, "check network namespace closed")
+		return "", nil, errors.Wrap(err, "check network namespace closed")
 	} else if closed {
-		return "", nil
+		return "", nil, nil
 	}
 
-	return sandbox.IP, nil
+	return sandbox.IP, sandbox.AdditionalIPs, nil
 }
 
 // toCRISandboxStatus converts sandbox metadata into CRI pod sandbox status.
-func toCRISandboxStatus(meta sandboxstore.Metadata, status sandboxstore.Status, ip string) *runtime.PodSandboxStatus {
+func toCRISandboxStatus(meta sandboxstore.Metadata, status sandboxstore.Status, ip string, additionalIPs []string) *runtime.PodSandboxStatus {
 	// Set sandbox state to NOTREADY by default.
 	state := runtime.PodSandboxState_SANDBOX_NOTREADY
 	if status.State == sandboxstore.StateReady {
 		state = runtime.PodSandboxState_SANDBOX_READY
 	}
 	nsOpts := meta.Config.GetLinux().GetSecurityContext().GetNamespaceOptions()
+	var ips []*runtime.PodIP
+	for _, additionalIP := range additionalIPs {
+		ips = append(ips, &runtime.PodIP{Ip: additionalIP})
+	}
 	return &runtime.PodSandboxStatus{
 		Id:        meta.ID,
 		Metadata:  meta.Config.GetMetadata(),
 		State:     state,
 		CreatedAt: status.CreatedAt.UnixNano(),
-		Network:   &runtime.PodSandboxNetworkStatus{Ip: ip},
+		Network: &runtime.PodSandboxNetworkStatus{
+			Ip:            ip,
+			AdditionalIps: ips,
+		},
 		Linux: &runtime.LinuxPodSandboxStatus{
 			Namespaces: &runtime.Namespace{
 				Options: &runtime.NamespaceOption{

pkg/server/sandbox_status_test.go

@@ -31,6 +31,7 @@ func TestPodSandboxStatus(t *testing.T) {
 		id = "test-id"
 		ip = "10.10.10.10"
 	)
+	additionalIPs := []string{"8.8.8.8", "2001:db8:85a3::8a2e:370:7334"}
 	createdAt := time.Now()
 	config := &runtime.PodSandboxConfig{
 		Metadata: &runtime.PodSandboxMetadata{
@@ -62,7 +63,17 @@ func TestPodSandboxStatus(t *testing.T) {
 		Id:        id,
 		Metadata:  config.GetMetadata(),
 		CreatedAt: createdAt.UnixNano(),
-		Network:   &runtime.PodSandboxNetworkStatus{Ip: ip},
+		Network: &runtime.PodSandboxNetworkStatus{
+			Ip: ip,
+			AdditionalIps: []*runtime.PodIP{
+				{
+					Ip: additionalIPs[0],
+				},
+				{
+					Ip: additionalIPs[1],
+				},
+			},
+		},
 		Linux: &runtime.LinuxPodSandboxStatus{
 			Namespaces: &runtime.Namespace{
 				Options: &runtime.NamespaceOption{
@@ -99,7 +110,7 @@ func TestPodSandboxStatus(t *testing.T) {
 			State:     test.state,
 		}
 		expected.State = test.expectedState
-		got := toCRISandboxStatus(metadata, status, ip)
+		got := toCRISandboxStatus(metadata, status, ip, additionalIPs)
 		assert.Equal(t, expected, got)
 	}
 }

pkg/server/sandbox_stop.go

@@ -79,7 +79,7 @@ func (c *criService) StopPodSandbox(ctx context.Context, r *runtime.StopPodSandb
 		} else if closed {
 			netNSPath = ""
 		}
-		if err := c.teardownPod(ctx, id, netNSPath, sandbox.Config); err != nil {
+		if err := c.teardownPodNetwork(ctx, id, netNSPath, sandbox.Config); err != nil {
 			return nil, errors.Wrapf(err, "failed to destroy network for sandbox %q", id)
 		}
 		if err = sandbox.NetNS.Remove(); err != nil {
@@ -155,8 +155,8 @@ func (c *criService) waitSandboxStop(ctx context.Context, sandbox sandboxstore.S
 	}
 }
 
-// teardownPod removes the network from the pod
+// teardownPodNetwork removes the network from the pod
-func (c *criService) teardownPod(ctx context.Context, id string, path string, config *runtime.PodSandboxConfig) error {
+func (c *criService) teardownPodNetwork(ctx context.Context, id string, path string, config *runtime.PodSandboxConfig) error {
 	if c.netPlugin == nil {
 		return errors.New("cni config not initialized")
 	}

pkg/server/update_runtime_config.go

@@ -17,8 +17,10 @@ limitations under the License.
 package server
 
 import (
+	"net"
 	"os"
 	"path/filepath"
+	"strings"
 	"text/template"
 
 	"github.com/containerd/containerd/log"
@@ -32,17 +34,36 @@ import (
 type cniConfigTemplate struct {
 	// PodCIDR is the cidr for pods on the node.
 	PodCIDR string
+	// PodCIDRRanges is the cidr ranges for pods on the node.
+	PodCIDRRanges []string
+	// Routes is a list of routes configured.
+	Routes []string
 }
 
+const (
 	// cniConfigFileName is the name of cni config file generated by containerd.
-const cniConfigFileName = "10-containerd-net.conflist"
+	cniConfigFileName = "10-containerd-net.conflist"
+	// zeroCIDRv6 is the null route for IPv6.
+	zeroCIDRv6 = "::/0"
+	// zeroCIDRv4 is the null route for IPv4.
+	zeroCIDRv4 = "0.0.0.0/0"
+)
 
 // UpdateRuntimeConfig updates the runtime config. Currently only handles podCIDR updates.
 func (c *criService) UpdateRuntimeConfig(ctx context.Context, r *runtime.UpdateRuntimeConfigRequest) (*runtime.UpdateRuntimeConfigResponse, error) {
-	podCIDR := r.GetRuntimeConfig().GetNetworkConfig().GetPodCidr()
+	podCIDRs := r.GetRuntimeConfig().GetNetworkConfig().GetPodCidr()
-	if podCIDR == "" {
+	if podCIDRs == "" {
 		return &runtime.UpdateRuntimeConfigResponse{}, nil
 	}
+	cidrs := strings.Split(podCIDRs, ",")
+	for i := range cidrs {
+		cidrs[i] = strings.TrimSpace(cidrs[i])
+	}
+	routes, err := getRoutes(cidrs)
+	if err != nil {
+		return nil, errors.Wrap(err, "get routes")
+	}
+
 	confTemplate := c.config.NetworkPluginConfTemplate
 	if confTemplate == "" {
 		log.G(ctx).Info("No cni config template is specified, wait for other system components to drop the config.")
@@ -70,8 +91,38 @@ func (c *criService) UpdateRuntimeConfig(ctx context.Context, r *runtime.UpdateR
 		return nil, errors.Wrapf(err, "failed to open cni config file %q", confFile)
 	}
 	defer f.Close()
-	if err := t.Execute(f, cniConfigTemplate{PodCIDR: podCIDR}); err != nil {
+	if err := t.Execute(f, cniConfigTemplate{
+		PodCIDR:       cidrs[0],
+		PodCIDRRanges: cidrs,
+		Routes:        routes,
+	}); err != nil {
 		return nil, errors.Wrapf(err, "failed to generate cni config file %q", confFile)
 	}
 	return &runtime.UpdateRuntimeConfigResponse{}, nil
 }
+
+// getRoutes generates required routes for the passed in cidrs.
+func getRoutes(cidrs []string) ([]string, error) {
+	var (
+		routes       []string
+		hasV4, hasV6 bool
+	)
+	for _, c := range cidrs {
+		_, cidr, err := net.ParseCIDR(c)
+		if err != nil {
+			return nil, err
+		}
+		if cidr.IP.To4() != nil {
+			hasV4 = true
+		} else {
+			hasV6 = true
+		}
+	}
+	if hasV4 {
+		routes = append(routes, zeroCIDRv4)
+	}
+	if hasV6 {
+		routes = append(routes, zeroCIDRv6)
+	}
+	return routes, nil
+}

pkg/server/update_runtime_config_test.go

@@ -45,14 +45,13 @@ func TestUpdateRuntimeConfig(t *testing.T) {
 		"ipam": {
 			"type": "host-local",
 			"subnet": "{{.PodCIDR}}",
-			"routes": [
+			"ranges": [{{range $i, $range := .PodCIDRRanges}}{{if $i}}, {{end}}[{"subnet": "{{$range}}"}]{{end}}],
-			{"dst": "0.0.0.0/0"}
+			"routes": [{{range $i, $route := .Routes}}{{if $i}}, {{end}}{"dst": "{{$route}}"}{{end}}]
-			]
 		}
 	},
 	]
 }`
-		testCIDR = "10.0.0.0/24"
+		testCIDR = "10.0.0.0/24, 2001:4860:4860::8888/32"
 		expected = `
 {
 	"name": "test-pod-network",
@@ -64,9 +63,8 @@ func TestUpdateRuntimeConfig(t *testing.T) {
 		"ipam": {
 			"type": "host-local",
 			"subnet": "10.0.0.0/24",
-			"routes": [
+			"ranges": [[{"subnet": "10.0.0.0/24"}], [{"subnet": "2001:4860:4860::8888/32"}]],
-			{"dst": "0.0.0.0/0"}
+			"routes": [{"dst": "0.0.0.0/0"}, {"dst": "::/0"}]
-			]
 		}
 	},
 	]

pkg/store/sandbox/metadata.go

@@ -55,6 +55,8 @@ type Metadata struct {
 	NetNSPath string
 	// IP of Pod if it is attached to non host network
 	IP string
+	// AdditionalIPs of the Pod if it is attached to non host network
+	AdditionalIPs []string
 	// RuntimeHandler is the runtime handler name of the pod.
 	RuntimeHandler string
 	// CNIresult resulting configuration for attached network namespace interfaces