cni/src/evioPlugin.go

498 lines
14 KiB
Go

package main
import (
"encoding/json"
"errors"
"fmt"
"log"
"net"
"os"
"os/exec"
"runtime"
"strings"
"syscall"
"github.com/containernetworking/cni/pkg/skel"
"github.com/containernetworking/cni/pkg/types"
"github.com/containernetworking/cni/pkg/types/current"
"github.com/containernetworking/cni/pkg/version"
"github.com/containernetworking/plugins/pkg/ip"
"github.com/containernetworking/plugins/pkg/ipam"
"github.com/containernetworking/plugins/pkg/ns"
"github.com/containernetworking/plugins/pkg/utils"
"github.com/digitalocean/go-openvswitch/ovs"
"github.com/j-keck/arping"
"github.com/vishvananda/netlink"
)
type NetConf struct {
types.NetConf
BrName string `json:"bridge"`
BrType string `json:"bridgeType"`
BrIP string `json:"bridgeIPv4"`
IsGW bool `json:"isGateway"`
IsDefaultGW bool `json:"isDefaultGateway"`
IPMasq bool `json:"isIPMasq"`
subnetPath string `json:"subnetPath"`
}
type gwInfo struct {
gws []net.IPNet
family int
defaultRouteFound bool
}
func loadNetConf(bytes []byte) (*NetConf, string, error) {
n := &NetConf{}
if err := json.Unmarshal(bytes, n); err != nil {
return nil, "", fmt.Errorf("failed to load network configuration: %v", err)
}
log.Printf("%+v", *n)
return n, n.CNIVersion, nil
}
func configureBridgeInterface(bridgeName string, gatewayAddress string) error {
i, err := net.InterfaceByName(bridgeName)
if err != nil {
log.Println("Bridge interface not found.")
return err
}
ipv4set := false
var ip net.IP
ipv4 := ""
addrs, err := i.Addrs()
if err != nil {
log.Println("Could not get addresses associated with the bridge.")
return err
}
for _, addr := range addrs {
switch v := addr.(type) {
case *net.IPAddr:
ip = v.IP
case *net.IPNet:
ip = v.IP
}
log.Printf("Bridge address %s\n", addr.String())
if ip.To4() != nil {
if strings.Compare(gatewayAddress, addr.String()) == 0 {
log.Printf("Interface %s already configured with address %s\n", bridgeName, addr.String())
ipv4set = true
} else {
ipv4 = addr.String()
}
}
}
if ipv4set == true {
return nil
}
// need to assign gateway address to switch and bring it up.
ipExecutable, err := exec.LookPath("ip")
if err != nil {
log.Println("failed to locate executable ip")
return err
}
if ipv4 != "" {
log.Println(" some other ipv4 address %s is assigned in place of %s ", ipv4, gatewayAddress)
}
cmdDelIP := &exec.Cmd{
Path: ipExecutable,
Args: []string{ipExecutable, "addr", "del", ipv4, "dev", bridgeName},
}
if ipv4 != "" {
if output, err := cmdDelIP.Output(); err != nil {
log.Println(err.Error())
return err
} else {
log.Println(output)
}
}
cmdSetIP := &exec.Cmd{
Path: ipExecutable,
Args: []string{ipExecutable, "addr", "add", gatewayAddress, "dev", bridgeName},
}
if output, err := cmdSetIP.Output(); err != nil {
log.Println(err.Error())
return err
} else {
log.Println(output)
}
cmdBringUP := &exec.Cmd{
Path: ipExecutable,
Args: []string{ipExecutable, "link", "set", bridgeName, "up"},
}
if output, err := cmdBringUP.Output(); err != nil {
log.Println(err.Error())
return err
} else {
log.Println(output)
}
return nil
}
func setupBridge(netconf *NetConf) (*netlink.Bridge, *current.Interface, error) {
br := &netlink.Bridge{
LinkAttrs: netlink.LinkAttrs{
Name: netconf.BrName,
MTU: 1500,
TxQLen: -1,
},
}
// this section adds and sets up a linux bridge
if netconf.BrType == "LXBR" {
err := netlink.LinkAdd(br)
if err != nil && err != syscall.EEXIST {
return nil, nil, err
}
if err := netlink.LinkSetUp(br); err != nil {
return nil, nil, err
}
} else if netconf.BrType == "OVS" {
// setting up an ovs bridge
ovsClient := ovs.New(ovs.Sudo())
if err := ovsClient.VSwitch.AddBridge(br.Attrs().Name); err != nil {
log.Fatalf("failed to add OVS bridge: %v", err)
}
}
return br, &current.Interface{
Name: br.Attrs().Name,
Mac: br.Attrs().HardwareAddr.String(),
}, nil
}
func setupVeth(br *netlink.Bridge, netconf *NetConf, args *skel.CmdArgs) (*current.Interface, *current.Interface, error) {
netns, err := ns.GetNS(args.Netns)
if err != nil {
log.Fatalf("Could not find network namespace %v", err)
return nil, nil, fmt.Errorf("Could not find network namespace %v", err)
}
contIface := &current.Interface{}
hostIface := &current.Interface{}
var handler = func(hostNS ns.NetNS) error {
hostVeth, containerVeth, err := ip.SetupVeth(args.IfName, 1500, hostNS)
if err != nil {
return err
}
contIface.Name = containerVeth.Name
contIface.Mac = containerVeth.HardwareAddr.String()
contIface.Sandbox = netns.Path()
hostIface.Name = hostVeth.Name
log.Printf("Created pod veth interface: %v\n", containerVeth.Name)
return nil
}
if err := netns.Do(handler); err != nil {
return nil, nil, err
}
hostVeth, err := netlink.LinkByName(hostIface.Name)
if err != nil {
return nil, nil, err
}
log.Printf("Located host veth interface: %v\n", hostVeth.Attrs().Name)
hostIface.Mac = hostVeth.Attrs().HardwareAddr.String()
if netconf.BrType == "LXBR" {
// below attaches veth interface to the bridge.
if err := netlink.LinkSetMaster(hostVeth, br); err != nil {
return nil, nil, err
}
} else if netconf.BrType == "OVS" {
// below attaches veth interface to ovs bridge
ovsClient := ovs.New(ovs.Sudo())
if err := ovsClient.VSwitch.AddPort(br.Attrs().Name, hostIface.Name); err != nil {
log.Printf("failed to add %v to bridge %v error %v", hostIface.Name, br.Attrs().Name, err)
}
log.Printf("Attached %v to %v\n", hostVeth.Attrs().Name, br.Name)
}
return hostIface, contIface, nil
}
func cmdAdd(args *skel.CmdArgs) error {
n, cniVersion, err := loadNetConf(args.StdinData)
if err != nil {
return err
}
log.Printf("%v\t %v\t %v", args.ContainerID, args.IfName, args.Netns)
log.Println("parsed configuration successfully !")
br, brInterface, err := setupBridge(n)
if err != nil {
return err
}
log.Printf("set up bridge %v successfully !\n", br.Name)
// set up IP address on the bridge and bring it up.
err = configureBridgeInterface(n.BrName, n.BrIP)
if err != nil {
log.Println("Failure in configuring bridge.")
return err
}
hostInterface, containerInterface, err := setupVeth(br, n, args)
if err != nil {
log.Println("Failure in setting up Veth interfaces.")
return err
}
log.Println("set up veth interfaces successfully !")
result := &current.Result{CNIVersion: cniVersion, Interfaces: []*current.Interface{brInterface, hostInterface, containerInterface}}
r, err := ipam.ExecAdd(n.IPAM.Type, args.StdinData)
if err != nil {
return err
}
var success bool = false
// release IP in case of failure
defer func() {
if !success {
os.Setenv("CNI_COMMAND", "DEL")
ipam.ExecDel(n.IPAM.Type, args.StdinData)
os.Setenv("CNI_COMMAND", "ADD")
}
}()
// Convert whatever the IPAM result was into the current Result type
ipamResult, err := current.NewResultFromResult(r)
if err != nil {
log.Printf("could not convert IPAM result %+v \n", ipamResult)
return err
}
log.Printf("result from IPAM : %+v\n", ipamResult)
result.IPs = ipamResult.IPs
result.Routes = ipamResult.Routes
if len(result.IPs) == 0 {
log.Printf("IPAM plugin provided no IP config\n")
return errors.New("IPAM plugin returned missing IP config")
}
netns, err := ns.GetNS(args.Netns)
if err != nil {
log.Printf("could not find namespace %v", args.Netns)
return err
}
for _, ipc := range result.IPs {
ipc.Interface = current.Int(2)
}
gwsV4, gwsV6, err := calcGateways(result, n)
if err != nil {
return err
}
// Configure the container hardware address and IP address(es)
if err := netns.Do(func(_ ns.NetNS) error {
contVeth, err := net.InterfaceByName(args.IfName)
if err != nil {
log.Printf("could not find interface %v", contVeth.Name)
return err
}
// Add the IP to the interface
if err := ipam.ConfigureIface(args.IfName, result); err != nil {
log.Printf("could not configure IP address on the interface %v", args.IfName)
return err
}
// Send a gratuitous arp
for _, ipc := range result.IPs {
if ipc.Version == "4" {
_ = arping.GratuitousArpOverIface(ipc.Address.IP, *contVeth)
}
}
return nil
}); err != nil {
log.Printf("something went wrong while trying to configure IP address on the interface !")
return err
}
if n.IsGW {
// Set the IP address(es) on the bridge and enable forwarding
for _, gws := range []*gwInfo{gwsV4, gwsV6} {
if gws.gws != nil {
if err = enableIPForward(gws.family); err != nil {
return fmt.Errorf("failed to enable forwarding: %v", err)
}
}
}
}
if n.IPMasq {
chain := utils.FormatChainName(n.Name, args.ContainerID)
comment := utils.FormatComment(n.Name, args.ContainerID)
for _, ipc := range result.IPs {
if err = ip.SetupIPMasq(ip.Network(&ipc.Address), chain, comment); err != nil {
log.Printf("something went wrong while to set up IPMasq %v!", err)
return err
}
log.Printf("IPMasq set up successfully !!")
}
}
if n.BrType == "LXBR" {
// commented out because accesses variables set when setting linux bridges
l, err := netlink.LinkByName(br.Name)
if err != nil {
log.Printf("could not lookup %q: %v", br.Name, err)
}
br, ok := l.(*netlink.Bridge)
if !ok {
log.Printf("%q already exists but is not a bridge", br.Name)
}
}
log.Printf("result %v\n", result)
return types.PrintResult(result, cniVersion)
}
func clearDeadPortsOnBridge(brName string) {
ovsClient := ovs.New(ovs.Sudo())
listOfPorts, err := ovsClient.VSwitch.ListPorts(brName)
// dead interfaces are cleared and interfaces deleted outside cni plugin, just check and remove from
// the bridge, happens for previously deleted namespaces not the current one being deleted.
if err != nil {
log.Printf("Could not list ports on bridge %s, error is %v", brName, err.Error())
} else {
for _, portName := range listOfPorts {
_, err := netlink.LinkByName(portName)
if err != nil {
if err = ovsClient.VSwitch.DeletePort(brName, portName); err != nil {
log.Printf("failed to remove %v from bridge %v error %v", brName, portName, err)
}
}
}
}
}
func cmdDel(args *skel.CmdArgs) error {
n, _, err := loadNetConf(args.StdinData)
if err != nil {
return err
}
log.Printf("%v\t %v\t %v", args.ContainerID, args.IfName, args.Netns)
log.Println("Delete: parsed configuration successfully !")
if args.Netns == "" {
return nil
}
var ipnets []*net.IPNet
err = ns.WithNetNSPath(args.Netns, func(_ ns.NetNS) error {
var err error
ipnets, err = ip.DelLinkByNameAddr(args.IfName)
if err != nil && err == ip.ErrLinkNotFound {
log.Printf("could not delete NS interface %v", err.Error())
return nil
}
return err
})
if n.IPMasq {
chain := utils.FormatChainName(n.Name, args.ContainerID)
comment := utils.FormatComment(n.Name, args.ContainerID)
for _, ipn := range ipnets {
if err := ip.TeardownIPMasq(ipn, chain, comment); err != nil {
log.Printf("could not reset IPMasq %v", err.Error())
return err
}
}
}
if n.BrType == "OVS" {
clearDeadPortsOnBridge(n.BrName)
}
if n.IPAM.Type != "" {
if err := ipam.ExecDel(n.IPAM.Type, args.StdinData); err != nil {
log.Printf("could not clear out IPAM %v", err.Error())
return err
}
}
return nil
}
func main() {
skel.PluginMain(cmdAdd, cmdDel, version.All)
}
func enableIPForward(family int) error {
if family == netlink.FAMILY_V4 {
return ip.EnableIP4Forward()
}
return ip.EnableIP6Forward()
}
func calcGateways(result *current.Result, n *NetConf) (*gwInfo, *gwInfo, error) {
gwsV4 := &gwInfo{}
gwsV6 := &gwInfo{}
for _, ipc := range result.IPs {
// Determine if this config is IPv4 or IPv6
var gws *gwInfo
defaultNet := &net.IPNet{}
switch {
case ipc.Address.IP.To4() != nil:
gws = gwsV4
gws.family = netlink.FAMILY_V4
defaultNet.IP = net.IPv4zero
case len(ipc.Address.IP) == net.IPv6len:
gws = gwsV6
gws.family = netlink.FAMILY_V6
defaultNet.IP = net.IPv6zero
default:
return nil, nil, fmt.Errorf("Unknown IP object: %v", ipc)
}
defaultNet.Mask = net.IPMask(defaultNet.IP)
// All IPs currently refer to the container interface
ipc.Interface = current.Int(2)
if n.IsGW {
ipc.Gateway = getGatewayIP(n)
}
// Add a default route for this family using the current
// gateway address if necessary.
if n.IsDefaultGW && !gws.defaultRouteFound {
for _, route := range result.Routes {
if route.GW != nil && defaultNet.String() == route.Dst.String() {
gws.defaultRouteFound = true
break
}
}
if !gws.defaultRouteFound {
result.Routes = append(
result.Routes,
&types.Route{Dst: *defaultNet, GW: ipc.Gateway},
)
gws.defaultRouteFound = true
}
}
// Append this gateway address to the list of gateways
if n.IsGW {
gw := net.IPNet{
IP: ipc.Gateway,
Mask: ipc.Address.Mask,
}
gws.gws = append(gws.gws, gw)
}
}
return gwsV4, gwsV6, nil
}
func calcGatewayIP(ipn *net.IPNet) net.IP {
nid := ipn.IP.Mask(ipn.Mask)
return ip.NextIP(nid)
}
func getGatewayIP(n *NetConf) net.IP {
gwIP := net.ParseIP(strings.Split(n.BrIP, "/")[0])
log.Printf("Gateway IPv4 address for bridge is %v !!", gwIP.String())
return gwIP
}
func init() {
// this ensures that main runs only on main thread (thread group leader).
// since namespace ops (unshare, setns) are done for a single thread, we
// must ensure that the goroutine does not jump from OS thread to thread
runtime.LockOSThread()
file, err := os.OpenFile("/var/log/evioPlugin.log", os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644)
if err != nil {
log.Fatal(err)
}
log.SetOutput(file)
}