[feat] synchronize NC version with NMA programmed goal state

cns/fakes/imdsclientfake.go

@@ -8,6 +8,7 @@ package fakes
 
 import (
 	"context"
+	"net"
 
 	"github.com/Azure/azure-container-networking/cns/imds"
 	"github.com/Azure/azure-container-networking/cns/wireserver"
@@ -57,3 +58,40 @@ func (m *MockIMDSClient) GetVMUniqueID(ctx context.Context) (string, error) {
 
 	return "55b8499d-9b42-4f85-843f-24ff69f4a643", nil
 }
+
+func (m *MockIMDSClient) GetNetworkInterfaces(ctx context.Context) ([]imds.NetworkInterface, error) {
+	if ctx.Value(SimulateError) != nil {
+		return nil, imds.ErrUnexpectedStatusCode
+	}
+
+	// Parse MAC addresses for testing
+	macAddr1, _ := net.ParseMAC("00:15:5d:01:02:01")
+	macAddr2, _ := net.ParseMAC("00:15:5d:01:02:02")
+
+	// Return some mock network interfaces for testing
+	return []imds.NetworkInterface{
+		{
+			InterfaceCompartmentID: "nc1",
+			MacAddress:             imds.HardwareAddr(macAddr1),
+		},
+		{
+			InterfaceCompartmentID: "nc2",
+			MacAddress:             imds.HardwareAddr(macAddr2),
+		},
+	}, nil
+}
+
+func (m *MockIMDSClient) GetIMDSVersions(ctx context.Context) (*imds.APIVersionsResponse, error) {
+	if ctx.Value(SimulateError) != nil {
+		return nil, imds.ErrUnexpectedStatusCode
+	}
+
+	// Return supported API versions including the expected one
+	return &imds.APIVersionsResponse{
+		APIVersions: []string{
+			"2017-03-01",
+			"2021-01-01",
+			"2025-07-24",
+		},
+	}, nil
+}

cns/imds/client.go

@@ -6,6 +6,7 @@ package imds
 import (
 	"context"
 	"encoding/json"
+	"net"
 	"net/http"
 	"net/url"
 
@@ -46,7 +47,10 @@ func RetryAttempts(attempts uint) ClientOption {
 const (
 	vmUniqueIDProperty    = "vmId"
 	imdsComputePath       = "/metadata/instance/compute"
-	imdsComputeAPIVersion = "api-version=2021-01-01"
+	imdsNetworkPath       = "/metadata/instance/network"
+	imdsVersionsPath      = "/metadata/versions"
+	imdsDefaultAPIVersion = "api-version=2021-01-01"
+	imdsNCDetailsVersion  = "api-version=2025-07-24"
 	imdsFormatJSON        = "format=json"
 	metadataHeaderKey     = "Metadata"
 	metadataHeaderValue   = "true"
@@ -79,7 +83,7 @@ func NewClient(opts ...ClientOption) *Client {
 func (c *Client) GetVMUniqueID(ctx context.Context) (string, error) {
 	var vmUniqueID string
 	err := retry.Do(func() error {
-		computeDoc, err := c.getInstanceComputeMetadata(ctx)
+		computeDoc, err := c.getInstanceMetadata(ctx, imdsComputePath, imdsDefaultAPIVersion)
 		if err != nil {
 			return errors.Wrap(err, "error getting IMDS compute metadata")
 		}
@@ -102,14 +106,40 @@ func (c *Client) GetVMUniqueID(ctx context.Context) (string, error) {
 	return vmUniqueID, nil
 }
 
-func (c *Client) getInstanceComputeMetadata(ctx context.Context) (map[string]any, error) {
-	imdsComputeURL, err := url.JoinPath(c.config.endpoint, imdsComputePath)
+func (c *Client) GetNetworkInterfaces(ctx context.Context) ([]NetworkInterface, error) {
+	var networkData NetworkInterfaces
+	err := retry.Do(func() error {
+		networkInterfaces, err := c.getInstanceMetadata(ctx, imdsNetworkPath, imdsNCDetailsVersion)
+		if err != nil {
+			return errors.Wrap(err, "error getting IMDS network metadata")
+		}
+
+		// Parse the network metadata to the expected structure
+		jsonData, err := json.Marshal(networkInterfaces)
+		if err != nil {
+			return errors.Wrap(err, "error marshaling network metadata")
+		}
+
+		if err := json.Unmarshal(jsonData, &networkData); err != nil {
+			return errors.Wrap(err, "error unmarshaling network metadata")
+		}
+		return nil
+	}, retry.Context(ctx), retry.Attempts(c.config.retryAttempts), retry.DelayType(retry.BackOffDelay))
 	if err != nil {
-		return nil, errors.Wrap(err, "unable to build path to IMDS compute metadata")
+		return nil, errors.Wrap(err, "external call failed")
 	}
-	imdsComputeURL = imdsComputeURL + "?" + imdsComputeAPIVersion + "&" + imdsFormatJSON
 
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, imdsComputeURL, http.NoBody)
+	return networkData.Interface, nil
+}
+
+func (c *Client) getInstanceMetadata(ctx context.Context, imdsMetadataPath, imdsAPIVersion string) (map[string]any, error) {
+	imdsRequestURL, err := url.JoinPath(c.config.endpoint, imdsMetadataPath)
+	if err != nil {
+		return nil, errors.Wrap(err, "unable to build path to IMDS metadata for path"+imdsMetadataPath)
+	}
+	imdsRequestURL = imdsRequestURL + "?" + imdsAPIVersion + "&" + imdsFormatJSON
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, imdsRequestURL, http.NoBody)
 	if err != nil {
 		return nil, errors.Wrap(err, "error building IMDS http request")
 	}
@@ -133,3 +163,86 @@ func (c *Client) getInstanceComputeMetadata(ctx context.Context) (map[string]any
 
 	return m, nil
 }
+
+func (c *Client) GetIMDSVersions(ctx context.Context) (*APIVersionsResponse, error) {
+	var versionsResp APIVersionsResponse
+	err := retry.Do(func() error {
+		// Build the URL for the versions endpoint
+		imdsRequestURL, err := url.JoinPath(c.config.endpoint, imdsVersionsPath)
+		if err != nil {
+			return errors.Wrap(err, "unable to build path to IMDS versions endpoint")
+		}
+
+		req, err := http.NewRequestWithContext(ctx, http.MethodGet, imdsRequestURL, http.NoBody)
+		if err != nil {
+			return errors.Wrap(err, "error building IMDS versions http request")
+		}
+
+		req.Header.Add(metadataHeaderKey, metadataHeaderValue)
+		resp, err := c.cli.Do(req)
+		if err != nil {
+			return errors.Wrap(err, "error querying IMDS versions API")
+		}
+		defer resp.Body.Close()
+
+		if resp.StatusCode != http.StatusOK {
+			return errors.Wrapf(ErrUnexpectedStatusCode, "unexpected status code %d", resp.StatusCode)
+		}
+
+		if err := json.NewDecoder(resp.Body).Decode(&versionsResp); err != nil {
+			return errors.Wrap(err, "error decoding IMDS versions response as json")
+		}
+
+		return nil
+	}, retry.Context(ctx), retry.Attempts(c.config.retryAttempts), retry.DelayType(retry.BackOffDelay))
+	if err != nil {
+		return nil, errors.Wrap(err, "exhausted retries querying IMDS versions")
+	}
+
+	return &versionsResp, nil
+}
+
+// Required for  marshaling/unmarshaling of mac address
+type HardwareAddr net.HardwareAddr
+
+func (h *HardwareAddr) MarshalJSON() ([]byte, error) {
+	data, err := json.Marshal(net.HardwareAddr(*h).String())
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to marshal hardware address")
+	}
+	return data, nil
+}
+
+func (h *HardwareAddr) UnmarshalJSON(data []byte) error {
+	var s string
+	if err := json.Unmarshal(data, &s); err != nil {
+		return errors.Wrap(err, "failed to unmarshal JSON data")
+	}
+	mac, err := net.ParseMAC(s)
+	if err != nil {
+		return errors.Wrap(err, "failed to parse MAC address")
+	}
+	*h = HardwareAddr(mac)
+	return nil
+}
+
+func (h *HardwareAddr) String() string {
+	return net.HardwareAddr(*h).String()
+}
+
+// NetworkInterface represents a network interface from IMDS
+type NetworkInterface struct {
+	// IMDS returns compartment fields - these are mapped to NC ID and NC version
+	MacAddress             HardwareAddr `json:"macAddress"`
+	InterfaceCompartmentID string       `json:"interfaceCompartmentID,omitempty"`
+}
+
+// NetworkInterfaces represents the network interfaces from IMDS
+type NetworkInterfaces struct {
+	Interface []NetworkInterface `json:"interface"`
+}
+
+// APIVersionsResponse represents versions form IMDS
+type APIVersionsResponse struct {
+	APIVersions []string `json:"apiVersions"`
+}