k3s/vendor/github.com/flannel-io/flannel/backend/hostgw/hostgw_windows.go

273 lines
9.1 KiB
Go

// Copyright 2018 flannel authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package hostgw
import (
"fmt"
"strings"
"sync"
"time"
"github.com/Microsoft/hcsshim"
"github.com/flannel-io/flannel/backend"
"github.com/flannel-io/flannel/pkg/ip"
"github.com/flannel-io/flannel/pkg/routing"
"github.com/flannel-io/flannel/subnet"
"github.com/pkg/errors"
"golang.org/x/net/context"
"k8s.io/apimachinery/pkg/util/json"
"k8s.io/apimachinery/pkg/util/wait"
log "k8s.io/klog"
)
func init() {
backend.Register("host-gw", New)
}
type HostgwBackend struct {
sm subnet.Manager
extIface *backend.ExternalInterface
}
func New(sm subnet.Manager, extIface *backend.ExternalInterface) (backend.Backend, error) {
if !extIface.ExtAddr.Equal(extIface.IfaceAddr) {
return nil, fmt.Errorf("your PublicIP differs from interface IP, meaning that probably you're on a NAT, which is not supported by host-gw backend")
}
be := &HostgwBackend{
sm: sm,
extIface: extIface,
}
return be, nil
}
func (be *HostgwBackend) RegisterNetwork(ctx context.Context, wg *sync.WaitGroup, config *subnet.Config) (backend.Network, error) {
// 1. Parse configuration
cfg := struct {
Name string
DNSServerList string
}{}
if len(config.Backend) > 0 {
if err := json.Unmarshal(config.Backend, &cfg); err != nil {
return nil, errors.Wrap(err, "error decoding windows host-gw backend config")
}
}
if len(cfg.Name) == 0 {
cfg.Name = "cbr0"
}
log.Infof("HOST-GW config: %+v", cfg)
n := &backend.RouteNetwork{
SimpleNetwork: backend.SimpleNetwork{
ExtIface: be.extIface,
},
SM: be.sm,
BackendType: "host-gw",
Mtu: be.extIface.Iface.MTU,
LinkIndex: be.extIface.Iface.Index,
}
n.GetRoute = func(lease *subnet.Lease) *routing.Route {
return &routing.Route{
DestinationSubnet: lease.Subnet.ToIPNet(),
GatewayAddress: lease.Attrs.PublicIP.ToIP(),
InterfaceIndex: n.LinkIndex,
}
}
// 2. Acquire the lease form subnet manager
attrs := subnet.LeaseAttrs{
PublicIP: ip.FromIP(be.extIface.ExtAddr),
BackendType: "host-gw",
}
l, err := be.sm.AcquireLease(ctx, &attrs)
switch err {
case nil:
n.SubnetLease = l
case context.Canceled, context.DeadlineExceeded:
return nil, err
default:
return nil, errors.Wrap(err, "failed to acquire lease")
}
// 3. Check if the network exists and has the expected settings
createNewNetwork := true
expectedSubnet := n.SubnetLease.Subnet
expectedAddressPrefix := expectedSubnet.String()
expectedGatewayAddress := (expectedSubnet.IP + 1).String()
expectedPodGatewayAddress := expectedSubnet.IP + 2
networkName := cfg.Name
var waitErr, lastErr error
existingNetwork, err := hcsshim.GetHNSNetworkByName(networkName)
if err == nil {
for _, subnet := range existingNetwork.Subnets {
if subnet.AddressPrefix == expectedAddressPrefix && subnet.GatewayAddress == expectedGatewayAddress {
createNewNetwork = false
log.Infof("Found existing HNSNetwork %s", networkName)
break
}
}
}
// 4. Create a new HNSNetwork
expectedNetwork := existingNetwork
if createNewNetwork {
if existingNetwork != nil {
if _, err := existingNetwork.Delete(); err != nil {
return nil, errors.Wrapf(err, "failed to delete existing HNSNetwork %s", networkName)
}
log.Infof("Deleted stale HNSNetwork %s", networkName)
}
expectedNetwork = &hcsshim.HNSNetwork{
Name: networkName,
Type: "L2Bridge",
DNSServerList: cfg.DNSServerList,
Subnets: []hcsshim.Subnet{
{
AddressPrefix: expectedAddressPrefix,
GatewayAddress: expectedGatewayAddress,
},
},
}
jsonRequest, err := json.Marshal(expectedNetwork)
if err != nil {
return nil, errors.Wrapf(err, "failed to marshal %+v", expectedNetwork)
}
log.Infof("Attempting to create HNSNetwork %s", string(jsonRequest))
newNetwork, err := hcsshim.HNSNetworkRequest("POST", "", string(jsonRequest))
if err != nil {
return nil, errors.Wrapf(err, "failed to create HNSNetwork %s", networkName)
}
// Wait for the network to populate Management IP
log.Infof("Waiting to get ManagementIP from HNSNetwork %s", networkName)
var newNetworkID = newNetwork.Id
waitErr = wait.Poll(500*time.Millisecond, 30*time.Second, func() (done bool, err error) {
newNetwork, lastErr = hcsshim.HNSNetworkRequest("GET", newNetworkID, "")
return newNetwork != nil && len(newNetwork.ManagementIP) != 0, nil
})
if waitErr == wait.ErrWaitTimeout {
// Do not swallow the root cause
if lastErr != nil {
waitErr = lastErr
}
return nil, errors.Wrapf(waitErr, "timeout, failed to get management IP from HNSNetwork %s", networkName)
}
// Wait for the interface with the management IP
log.Infof("Waiting to get net interface for HNSNetwork %s (%s)", networkName, newNetwork.ManagementIP)
managementIP, err := ip.ParseIP4(newNetwork.ManagementIP)
if err != nil {
return nil, errors.Wrapf(err, "Failed to parse management ip (%s)", newNetwork.ManagementIP)
}
waitErr = wait.Poll(500*time.Millisecond, 5*time.Second, func() (done bool, err error) {
_, lastErr = ip.GetInterfaceByIP(managementIP.ToIP())
return lastErr == nil, nil
})
if waitErr == wait.ErrWaitTimeout {
return nil, errors.Wrapf(lastErr, "timeout, failed to get net interface for HNSNetwork %s (%s)", networkName, newNetwork.ManagementIP)
}
log.Infof("Created HNSNetwork %s", networkName)
expectedNetwork = newNetwork
}
// 5. Ensure a 1.2 endpoint on this network in the host compartment
createNewBridgeEndpoint := true
bridgeEndpointName := networkName + "_ep"
existingBridgeEndpoint, err := hcsshim.GetHNSEndpointByName(bridgeEndpointName)
if err == nil && existingBridgeEndpoint.IPAddress.String() == expectedPodGatewayAddress.String() {
log.Infof("Found existing bridge HNSEndpoint %s", bridgeEndpointName)
createNewBridgeEndpoint = false
}
// 6. Create a bridge HNSEndpoint
expectedBridgeEndpoint := existingBridgeEndpoint
if createNewBridgeEndpoint {
if existingBridgeEndpoint != nil {
if _, err = existingBridgeEndpoint.Delete(); err != nil {
return nil, errors.Wrapf(err, "failed to delete existing bridge HNSEndpoint %s", bridgeEndpointName)
}
log.Infof("Deleted stale bridge HNSEndpoint %s", bridgeEndpointName)
}
expectedBridgeEndpoint = &hcsshim.HNSEndpoint{
Name: bridgeEndpointName,
IPAddress: expectedPodGatewayAddress.ToIP(),
VirtualNetwork: expectedNetwork.Id,
}
log.Infof("Attempting to create bridge HNSEndpoint %+v", expectedBridgeEndpoint)
if expectedBridgeEndpoint, err = expectedBridgeEndpoint.Create(); err != nil {
return nil, errors.Wrapf(err, "failed to create bridge HNSEndpoint %s", bridgeEndpointName)
}
log.Infof("Created bridge HNSEndpoint %s", bridgeEndpointName)
}
// Wait for the bridgeEndpoint to attach to the host
log.Infof("Waiting to attach bridge endpoint %s to host", bridgeEndpointName)
waitErr = wait.Poll(500*time.Millisecond, 5*time.Second, func() (done bool, err error) {
lastErr = expectedBridgeEndpoint.HostAttach(1)
if lastErr == nil {
return true, nil
}
// See https://github.com/flannel-io/flannel/issues/1391 and
// hcsshim lacks some validations to detect the error, so we judge it by error message.
if strings.Contains(lastErr.Error(), "This endpoint is already attached to the switch.") {
return true, nil
}
return false, nil
})
if waitErr == wait.ErrWaitTimeout {
return nil, errors.Wrapf(lastErr, "failed to hot attach bridge HNSEndpoint %s to host compartment", bridgeEndpointName)
}
log.Infof("Attached bridge endpoint %s to host successfully", bridgeEndpointName)
// 7. Enable forwarding on the host interface and endpoint
for _, interfaceIpAddress := range []string{expectedNetwork.ManagementIP, expectedBridgeEndpoint.IPAddress.String()} {
ipv4, err := ip.ParseIP4(interfaceIpAddress)
if err != nil {
return nil, errors.Wrapf(err, "Failed to parse expected net interface ip (%s)", interfaceIpAddress)
}
netInterface, err := ip.GetInterfaceByIP(ipv4.ToIP())
if err != nil {
return nil, errors.Wrapf(err, "failed to find interface for IP Address %s", interfaceIpAddress)
}
log.Infof("Found %+v interface with IP %s", netInterface, interfaceIpAddress)
// When a new hns network is created, the interface is modified, esp the name, index
if expectedNetwork.ManagementIP == ipv4.String() {
n.LinkIndex = netInterface.Index
n.Name = netInterface.Name
}
if err := ip.EnableForwardingForInterface(netInterface); err != nil {
return nil, errors.Wrapf(err, "failed to enable forwarding on %s index %d", netInterface.Name, netInterface.Index)
}
log.Infof("Enabled forwarding on %s index %d", netInterface.Name, netInterface.Index)
}
return n, nil
}