Allow specifying on which interface the Azure IPAM should allocate IP…

…s on

Signed-off-by: Vlad Ungureanu <vladu@palantir.com>

pkg/azure/ipam/node.go

@@ -29,6 +29,9 @@ import (
 
 // Node represents a node representing an Azure instance
 type Node struct {
+	// k8sObj is the CiliumNode custom resource representing the node
+	k8sObj *v2.CiliumNode
+
 	// node contains the general purpose fields of a node
 	node *ipam.Node
 
@@ -38,6 +41,7 @@ type Node struct {
 
 // UpdatedNode is called when an update to the CiliumNode is received.
 func (n *Node) UpdatedNode(obj *v2.CiliumNode) {
+	n.k8sObj = obj
 }
 
 // PopulateStatusFields fills in the status field of the CiliumNode custom
@@ -66,12 +70,23 @@ func (n *Node) ReleaseIPs(ctx context.Context, r *ipam.ReleaseAction) error {
 // PrepareIPAllocation returns the number of IPs that can be allocated/created.
 func (n *Node) PrepareIPAllocation(scopedLog *logrus.Entry) (a *ipam.AllocationAction, err error) {
 	a = &ipam.AllocationAction{}
+	requiredIfaceName := n.k8sObj.Spec.Azure.InterfaceName
 	err = n.manager.instances.ForeachInterface(n.node.InstanceID(), func(instanceID, interfaceID string, interfaceObj ipamTypes.InterfaceRevision) error {
 		iface, ok := interfaceObj.Resource.(*types.AzureInterface)
 		if !ok {
 			return fmt.Errorf("invalid interface object")
 		}
 
+		if requiredIfaceName != "" {
+			if iface.Name != requiredIfaceName {
+				scopedLog.WithFields(logrus.Fields{
+					"ifaceName":    iface.Name,
+					"requiredName": requiredIfaceName,
+				}).Debug("Not considering interface for allocation sice it does not match the required name")
+				return nil
+			}
+		}
+
 		scopedLog.WithFields(logrus.Fields{
 			"id":           iface.ID,
 			"numAddresses": len(iface.Addresses),

pkg/azure/types/types.go

@@ -36,6 +36,23 @@ const (
 	StateSucceeded = "succeeded"
 )
 
+// AzureSpec is the Azure specification of a node running via the Azure IPAM
+//
+// The Azure specification can either be provided explicitly by the user or the
+// cilium agent running on the node can be instructed to create the CiliumNode
+// custom resource along with an Azure specification when the node registers
+// itself to the Kubernetes cluster.
+// This struct is embedded into v2.CiliumNode
+//
+// +k8s:deepcopy-gen=true
+type AzureSpec struct {
+	// InterfaceName is the name of the interface the cilium-operator
+	// will use to allocate all the IPs on
+	//
+	// +optional
+	InterfaceName string `json:"interface-name,omitempty"`
+}
+
 // AzureStatus is the status of Azure addressing of the node
 //
 // This struct is embedded into v2.CiliumNode

pkg/k8s/apis/cilium.io/v2/register.go

@@ -398,6 +398,10 @@ func createNodeCRD(clientset apiextensionsclient.Interface) error {
 											Type:        "string",
 											Description: "instance-id is the Azure specific identifier of the node",
 										},
+										"interface-name": {
+											Type:        "string",
+											Description: "interface-name represents the name of the interface on which additional IP addreses will be allocated",
+										},
 									},
 								},
 								"eni": {

pkg/k8s/apis/cilium.io/v2/types.go

@@ -673,6 +673,11 @@ type NodeSpec struct {
 	// +optional
 	ENI eniTypes.ENISpec `json:"eni,omitempty"`
 
+	// Azure is the Azure IPAM specific configuration
+	//
+	// +optional
+	Azure azureTypes.AzureSpec `json:"azure,omitempty"`
+
 	// IPAM is the address management specification. This section can be
 	// populated by a user or it can be automatically populated by an IPAM
 	// operator

pkg/nodediscovery/nodediscovery.go

@@ -332,6 +332,18 @@ func (n *NodeDiscovery) UpdateCiliumNodeResource() {
 		// returned by the Azure API. Convert it to lower case for
 		// consistent results.
 		nodeResource.Spec.InstanceID = strings.ToLower(strings.TrimPrefix(providerID, azureTypes.ProviderPrefix))
+
+		if c := n.NetConf; c != nil {
+			if c.IPAM.MinAllocate != 0 {
+				nodeResource.Spec.IPAM.MinAllocate = c.IPAM.MinAllocate
+			}
+			if c.IPAM.PreAllocate != 0 {
+				nodeResource.Spec.IPAM.PreAllocate = c.IPAM.PreAllocate
+			}
+			if c.Azure.InterfaceName != "" {
+				nodeResource.Spec.Azure.InterfaceName = c.Azure.InterfaceName
+			}
+		}
 	}
 
 	if performUpdate {

plugins/cilium-cni/types/types.go

@@ -21,6 +21,7 @@ import (
 	"net"
 
 	eniTypes "github.com/cilium/cilium/pkg/aws/eni/types"
+	azureTypes "github.com/cilium/cilium/pkg/azure/types"
 	ipamTypes "github.com/cilium/cilium/pkg/ipam/types"
 
 	cniTypes "github.com/containernetworking/cni/pkg/types"
@@ -31,11 +32,12 @@ import (
 // NetConf is the Cilium specific CNI network configuration
 type NetConf struct {
 	cniTypes.NetConf
-	MTU         int                `json:"mtu"`
-	Args        Args               `json:"args"`
-	ENI         eniTypes.ENISpec   `json:"eni,omitempty"`
-	IPAM        ipamTypes.IPAMSpec `json:"ipam,omitempty"`
-	EnableDebug bool               `json:"enable-debug"`
+	MTU         int                  `json:"mtu"`
+	Args        Args                 `json:"args"`
+	ENI         eniTypes.ENISpec     `json:"eni,omitempty"`
+	Azure       azureTypes.AzureSpec `json:"azure,omitempty"`
+	IPAM        ipamTypes.IPAMSpec   `json:"ipam,omitempty"`
+	EnableDebug bool                 `json:"enable-debug"`
 }
 
 // NetConfList is a CNI chaining configuration

plugins/cilium-cni/types/types_test.go

@@ -23,6 +23,7 @@ import (
 	"testing"
 
 	eniTypes "github.com/cilium/cilium/pkg/aws/eni/types"
+	azureTypes "github.com/cilium/cilium/pkg/azure/types"
 	"github.com/cilium/cilium/pkg/checker"
 	ipamTypes "github.com/cilium/cilium/pkg/ipam/types"
 
@@ -214,6 +215,40 @@ func (t *CNITypesSuite) TestReadCNIConfENIv2WithPlugins(c *check.C) {
 	testConfRead(c, confFile1, &netConf1)
 }
 
+func (t *CNITypesSuite) TestReadCNIConfAzurev2WithPlugins(c *check.C) {
+	confFile1 := `
+{
+  "cniVersion":"0.3.1",
+  "name":"cilium",
+  "plugins": [
+    {
+      "cniVersion":"0.3.1",
+      "type":"cilium-cni",
+      "azure": {
+        "interface-name": "eth1"
+      },
+      "ipam": {
+        "pre-allocate": 5
+      }
+    }
+  ]
+}
+`
+	netConf1 := NetConf{
+		NetConf: cnitypes.NetConf{
+			CNIVersion: "0.3.1",
+			Type:       "cilium-cni",
+		},
+		Azure: azureTypes.AzureSpec{
+			InterfaceName: "eth1",
+		},
+		IPAM: ipamTypes.IPAMSpec{
+			PreAllocate: 5,
+		},
+	}
+	testConfRead(c, confFile1, &netConf1)
+}
+
 func (t *CNITypesSuite) TestReadCNIConfError(c *check.C) {
 	// Try to read errorneous CNI configuration file with MTU provided as
 	// string instead of int