Added initial CNI support

Author: ofiliz

cni/cni.go

@@ -0,0 +1,54 @@
+// Copyright Microsoft Corp.
+// All rights reserved.
+
+package cni
+
+import (
+	"encoding/json"
+
+	cniSkel "github.com/containernetworking/cni/pkg/skel"
+	cniTypes "github.com/containernetworking/cni/pkg/types"
+)
+
+// Plugin is the interface implemented by CNI plugins.
+type Plugin interface {
+	Add(args *cniSkel.CmdArgs) error
+	Delete(args *cniSkel.CmdArgs) error
+
+	AddImpl(args *cniSkel.CmdArgs, nwCfg *NetworkConfig) (*cniTypes.Result, error)
+	DeleteImpl(args *cniSkel.CmdArgs, nwCfg *NetworkConfig) (*cniTypes.Result, error)
+}
+
+// NetworkConfig represents the Azure CNI plugin's network configuration.
+type NetworkConfig struct {
+	CniVersion string `json:"cniVersion"`
+	Name       string `json:"name"`
+	Type       string `json:"type"`
+	Bridge     string `json:"bridge"`
+	IfName     string `json:"ifName"`
+	Ipam       struct {
+		Type      string `json:"type"`
+		AddrSpace string `json:"addressSpace"`
+		Subnet    string `json:"subnet"`
+		Address   string `json:"ipAddress"`
+		Result    string `json:"result"`
+	}
+}
+
+// ParseNetworkConfig unmarshals network configuration from bytes.
+func ParseNetworkConfig(b []byte) (*NetworkConfig, error) {
+	nwCfg := NetworkConfig{}
+
+	err := json.Unmarshal(b, &nwCfg)
+	if err != nil {
+		return nil, err
+	}
+
+	return &nwCfg, nil
+}
+
+// Serialize marshals a network configuration to bytes.
+func (nwcfg *NetworkConfig) Serialize() []byte {
+	bytes, _ := json.Marshal(nwcfg)
+	return bytes
+}

cni/ipam/ipam.go

@@ -0,0 +1,253 @@
+// Copyright Microsoft Corp.
+// All rights reserved.
+
+package ipam
+
+import (
+	"net"
+
+	"github.com/Azure/azure-container-networking/cni"
+	"github.com/Azure/azure-container-networking/common"
+	"github.com/Azure/azure-container-networking/ipam"
+	"github.com/Azure/azure-container-networking/log"
+
+	cniSkel "github.com/containernetworking/cni/pkg/skel"
+	cniTypes "github.com/containernetworking/cni/pkg/types"
+)
+
+const (
+	// Plugin name.
+	name = "ipam"
+
+	// The default address space ID used when an explicit ID is not specified.
+	defaultAddressSpaceId = "LocalDefaultAddressSpace"
+)
+
+// IpamPlugin represents a CNI IPAM plugin.
+type ipamPlugin struct {
+	*common.Plugin
+	am ipam.AddressManager
+}
+
+// NewPlugin creates a new ipamPlugin object.
+func NewPlugin(config *common.PluginConfig) (*ipamPlugin, error) {
+	// Setup base plugin.
+	plugin, err := common.NewPlugin(name, config.Version)
+	if err != nil {
+		return nil, err
+	}
+
+	// Setup address manager.
+	am, err := ipam.NewAddressManager()
+	if err != nil {
+		return nil, err
+	}
+
+	config.IpamApi = am
+
+	return &ipamPlugin{
+		Plugin: plugin,
+		am:     am,
+	}, nil
+}
+
+// Starts the plugin.
+func (plugin *ipamPlugin) Start(config *common.PluginConfig) error {
+	// Initialize base plugin.
+	err := plugin.Initialize(config)
+	if err != nil {
+		log.Printf("[ipam] Failed to initialize base plugin, err:%v.", err)
+		return err
+	}
+
+	// Initialize address manager.
+	environment := plugin.GetOption(common.OptEnvironmentKey)
+	err = plugin.am.Initialize(config, environment)
+	if err != nil {
+		log.Printf("[ipam] Failed to initialize address manager, err:%v.", err)
+		return err
+	}
+
+	log.Printf("[ipam] Plugin started.")
+
+	return nil
+}
+
+// Stops the plugin.
+func (plugin *ipamPlugin) Stop() {
+	plugin.am.Uninitialize()
+	plugin.Uninitialize()
+	log.Printf("[ipam] Plugin stopped.")
+}
+
+//
+// CNI implementation
+// https://github.com/containernetworking/cni/blob/master/SPEC.md
+//
+
+// Add handles CNI add commands.
+func (plugin *ipamPlugin) Add(args *cniSkel.CmdArgs) error {
+	log.Printf("[ipam] Processing ADD command with args {ContainerID:%v Netns:%v IfName:%v Args:%v Path:%v}.",
+		args.ContainerID, args.Netns, args.IfName, args.Args, args.Path)
+
+	// Parse network configuration from stdin.
+	nwCfg, err := cni.ParseNetworkConfig(args.StdinData)
+	if err != nil {
+		log.Printf("[ipam] Failed to parse network configuration: %v.", err)
+		return nil
+	}
+
+	log.Printf("[ipam] Read network configuration %+v.", nwCfg)
+
+	// Assume default address space if not specified.
+	if nwCfg.Ipam.AddrSpace == "" {
+		nwCfg.Ipam.AddrSpace = defaultAddressSpaceId
+	}
+
+	// Check if an address pool is specified.
+	if nwCfg.Ipam.Subnet == "" {
+		// Allocate an address pool.
+		poolId, subnet, err := plugin.am.RequestPool(nwCfg.Ipam.AddrSpace, "", "", nil, false)
+		if err != nil {
+			log.Printf("[ipam] Failed to allocate pool, err:%v.", err)
+			return nil
+		}
+
+		nwCfg.Ipam.Subnet = subnet
+		log.Printf("[ipam] Allocated address poolId %v with subnet %v.", poolId, subnet)
+	}
+
+	// Allocate an address for the endpoint.
+	address, err := plugin.am.RequestAddress(nwCfg.Ipam.AddrSpace, nwCfg.Ipam.Subnet, nwCfg.Ipam.Address, nil)
+	if err != nil {
+		log.Printf("[ipam] Failed to allocate address, err:%v.", err)
+		return nil
+	}
+
+	log.Printf("[ipam] Allocated address %v.", address)
+
+	// Output the result.
+	ip, cidr, err := net.ParseCIDR(address)
+	cidr.IP = ip
+	if err != nil {
+		log.Printf("[ipam] Failed to parse address, err:%v.", err)
+		return nil
+	}
+
+	result := &cniTypes.Result{
+		IP4: &cniTypes.IPConfig{IP: *cidr},
+	}
+
+	// Output response.
+	if nwCfg.Ipam.Result == "" {
+		result.Print()
+	} else {
+		args.Args = result.String()
+	}
+
+	log.Printf("[ipam] ADD succeeded with output %+v.", result)
+
+	return err
+}
+
+// Delete handles CNI delete commands.
+func (plugin *ipamPlugin) Delete(args *cniSkel.CmdArgs) error {
+	log.Printf("[ipam] Processing DEL command with args {ContainerID:%v Netns:%v IfName:%v Args:%v Path:%v}.",
+		args.ContainerID, args.Netns, args.IfName, args.Args, args.Path)
+
+	// Parse network configuration from stdin.
+	nwCfg, err := cni.ParseNetworkConfig(args.StdinData)
+	if err != nil {
+		log.Printf("[ipam] Failed to parse network configuration: %v.", err)
+		return nil
+	}
+
+	log.Printf("[ipam] Read network configuration %+v.", nwCfg)
+
+	// Process command.
+	result, err := plugin.DeleteImpl(args, nwCfg)
+	if err != nil {
+		log.Printf("[ipam] Failed to process command: %v.", err)
+		return nil
+	}
+
+	// Output response.
+	if result != nil {
+		result.Print()
+	}
+
+	log.Printf("[ipam] DEL succeeded with output %+v.", result)
+
+	return err
+}
+
+// AddImpl handles CNI add commands.
+func (plugin *ipamPlugin) AddImpl(args *cniSkel.CmdArgs, nwCfg *cni.NetworkConfig) (*cniTypes.Result, error) {
+	// Assume default address space if not specified.
+	if nwCfg.Ipam.AddrSpace == "" {
+		nwCfg.Ipam.AddrSpace = defaultAddressSpaceId
+	}
+
+	// Check if an address pool is specified.
+	if nwCfg.Ipam.Subnet == "" {
+		// Allocate an address pool.
+		poolId, subnet, err := plugin.am.RequestPool(nwCfg.Ipam.AddrSpace, "", "", nil, false)
+		if err != nil {
+			log.Printf("[ipam] Failed to allocate pool, err:%v.", err)
+			return nil, err
+		}
+
+		nwCfg.Ipam.Subnet = subnet
+		log.Printf("[ipam] Allocated address poolId %v with subnet %v.", poolId, subnet)
+	}
+
+	// Allocate an address for the endpoint.
+	address, err := plugin.am.RequestAddress(nwCfg.Ipam.AddrSpace, nwCfg.Ipam.Subnet, nwCfg.Ipam.Address, nil)
+	if err != nil {
+		log.Printf("[ipam] Failed to allocate address, err:%v.", err)
+		return nil, err
+	}
+
+	log.Printf("[ipam] Allocated address %v.", address)
+
+	// Output the result.
+	ip, cidr, err := net.ParseCIDR(address)
+	cidr.IP = ip
+	if err != nil {
+		log.Printf("[ipam] Failed to parse address, err:%v.", err)
+		return nil, err
+	}
+
+	result := &cniTypes.Result{
+		IP4: &cniTypes.IPConfig{IP: *cidr},
+	}
+
+	return result, nil
+}
+
+// DeleteImpl handles CNI delete commands.
+func (plugin *ipamPlugin) DeleteImpl(args *cniSkel.CmdArgs, nwCfg *cni.NetworkConfig) (*cniTypes.Result, error) {
+	// Assume default address space if not specified.
+	if nwCfg.Ipam.AddrSpace == "" {
+		nwCfg.Ipam.AddrSpace = defaultAddressSpaceId
+	}
+
+	// If an address is specified, release that address. Otherwise, release the pool.
+	if nwCfg.Ipam.Address != "" {
+		// Release the address.
+		err := plugin.am.ReleaseAddress(nwCfg.Ipam.AddrSpace, nwCfg.Ipam.Subnet, nwCfg.Ipam.Address)
+		if err != nil {
+			log.Printf("[cni] Failed to release address, err:%v.", err)
+			return nil, err
+		}
+	} else {
+		// Release the pool.
+		err := plugin.am.ReleasePool(nwCfg.Ipam.AddrSpace, nwCfg.Ipam.Subnet)
+		if err != nil {
+			log.Printf("[cni] Failed to release pool, err:%v.", err)
+			return nil, err
+		}
+	}
+
+	return nil, nil
+}