317 lines
12 KiB
Go
317 lines
12 KiB
Go
/*
|
|
Copyright 2016 The Kubernetes 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 kubelet
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"io/ioutil"
|
|
"strings"
|
|
|
|
"github.com/golang/glog"
|
|
"k8s.io/apimachinery/pkg/util/sets"
|
|
"k8s.io/kubernetes/pkg/api/v1"
|
|
"k8s.io/kubernetes/pkg/apis/componentconfig"
|
|
"k8s.io/kubernetes/pkg/kubelet/network"
|
|
"k8s.io/kubernetes/pkg/util/bandwidth"
|
|
utiliptables "k8s.io/kubernetes/pkg/util/iptables"
|
|
)
|
|
|
|
const (
|
|
// the mark-for-masquerade chain
|
|
// TODO: clean up this logic in kube-proxy
|
|
KubeMarkMasqChain utiliptables.Chain = "KUBE-MARK-MASQ"
|
|
|
|
// the mark-for-drop chain
|
|
KubeMarkDropChain utiliptables.Chain = "KUBE-MARK-DROP"
|
|
|
|
// kubernetes postrouting rules
|
|
KubePostroutingChain utiliptables.Chain = "KUBE-POSTROUTING"
|
|
|
|
// kubernetes firewall rules
|
|
KubeFirewallChain utiliptables.Chain = "KUBE-FIREWALL"
|
|
)
|
|
|
|
// effectiveHairpinMode determines the effective hairpin mode given the
|
|
// configured mode, container runtime, and whether cbr0 should be configured.
|
|
func effectiveHairpinMode(hairpinMode componentconfig.HairpinMode, containerRuntime string, networkPlugin string) (componentconfig.HairpinMode, error) {
|
|
// The hairpin mode setting doesn't matter if:
|
|
// - We're not using a bridge network. This is hard to check because we might
|
|
// be using a plugin.
|
|
// - It's set to hairpin-veth for a container runtime that doesn't know how
|
|
// to set the hairpin flag on the veth's of containers. Currently the
|
|
// docker runtime is the only one that understands this.
|
|
// - It's set to "none".
|
|
if hairpinMode == componentconfig.PromiscuousBridge || hairpinMode == componentconfig.HairpinVeth {
|
|
// Only on docker.
|
|
if containerRuntime != "docker" {
|
|
glog.Warningf("Hairpin mode set to %q but container runtime is %q, ignoring", hairpinMode, containerRuntime)
|
|
return componentconfig.HairpinNone, nil
|
|
}
|
|
if hairpinMode == componentconfig.PromiscuousBridge && networkPlugin != "kubenet" {
|
|
// This is not a valid combination, since promiscuous-bridge only works on kubenet. Users might be using the
|
|
// default values (from before the hairpin-mode flag existed) and we
|
|
// should keep the old behavior.
|
|
glog.Warningf("Hairpin mode set to %q but kubenet is not enabled, falling back to %q", hairpinMode, componentconfig.HairpinVeth)
|
|
return componentconfig.HairpinVeth, nil
|
|
}
|
|
} else if hairpinMode != componentconfig.HairpinNone {
|
|
return "", fmt.Errorf("unknown value: %q", hairpinMode)
|
|
}
|
|
return hairpinMode, nil
|
|
}
|
|
|
|
// providerRequiresNetworkingConfiguration returns whether the cloud provider
|
|
// requires special networking configuration.
|
|
func (kl *Kubelet) providerRequiresNetworkingConfiguration() bool {
|
|
// TODO: We should have a mechanism to say whether native cloud provider
|
|
// is used or whether we are using overlay networking. We should return
|
|
// true for cloud providers if they implement Routes() interface and
|
|
// we are not using overlay networking.
|
|
if kl.cloud == nil || kl.cloud.ProviderName() != "gce" {
|
|
return false
|
|
}
|
|
_, supported := kl.cloud.Routes()
|
|
return supported
|
|
}
|
|
|
|
// parseResolveConf reads a resolv.conf file from the given reader, and parses
|
|
// it into nameservers and searches, possibly returning an error.
|
|
// TODO: move to utility package
|
|
func (kl *Kubelet) parseResolvConf(reader io.Reader) (nameservers []string, searches []string, err error) {
|
|
file, err := ioutil.ReadAll(reader)
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
|
|
// Lines of the form "nameserver 1.2.3.4" accumulate.
|
|
nameservers = []string{}
|
|
|
|
// Lines of the form "search example.com" overrule - last one wins.
|
|
searches = []string{}
|
|
|
|
lines := strings.Split(string(file), "\n")
|
|
for l := range lines {
|
|
trimmed := strings.TrimSpace(lines[l])
|
|
if strings.HasPrefix(trimmed, "#") {
|
|
continue
|
|
}
|
|
fields := strings.Fields(trimmed)
|
|
if len(fields) == 0 {
|
|
continue
|
|
}
|
|
if fields[0] == "nameserver" {
|
|
nameservers = append(nameservers, fields[1:]...)
|
|
}
|
|
if fields[0] == "search" {
|
|
searches = fields[1:]
|
|
}
|
|
}
|
|
|
|
// There used to be code here to scrub DNS for each cloud, but doesn't
|
|
// make sense anymore since cloudproviders are being factored out.
|
|
// contact @thockin or @wlan0 for more information
|
|
|
|
return nameservers, searches, nil
|
|
}
|
|
|
|
// cleanupBandwidthLimits updates the status of bandwidth-limited containers
|
|
// and ensures that only the appropriate CIDRs are active on the node.
|
|
func (kl *Kubelet) cleanupBandwidthLimits(allPods []*v1.Pod) error {
|
|
if kl.shaper == nil {
|
|
return nil
|
|
}
|
|
currentCIDRs, err := kl.shaper.GetCIDRs()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
possibleCIDRs := sets.String{}
|
|
for ix := range allPods {
|
|
pod := allPods[ix]
|
|
ingress, egress, err := bandwidth.ExtractPodBandwidthResources(pod.Annotations)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if ingress == nil && egress == nil {
|
|
glog.V(8).Infof("Not a bandwidth limited container...")
|
|
continue
|
|
}
|
|
status, found := kl.statusManager.GetPodStatus(pod.UID)
|
|
if !found {
|
|
// TODO(random-liu): Cleanup status get functions. (issue #20477)
|
|
s, err := kl.containerRuntime.GetPodStatus(pod.UID, pod.Name, pod.Namespace)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
status = kl.generateAPIPodStatus(pod, s)
|
|
}
|
|
if status.Phase == v1.PodRunning {
|
|
possibleCIDRs.Insert(fmt.Sprintf("%s/32", status.PodIP))
|
|
}
|
|
}
|
|
for _, cidr := range currentCIDRs {
|
|
if !possibleCIDRs.Has(cidr) {
|
|
glog.V(2).Infof("Removing CIDR: %s (%v)", cidr, possibleCIDRs)
|
|
if err := kl.shaper.Reset(cidr); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// syncNetworkStatus updates the network state
|
|
func (kl *Kubelet) syncNetworkStatus() {
|
|
// For cri integration, network state will be updated in updateRuntimeUp,
|
|
// we'll get runtime network status through cri directly.
|
|
// TODO: Remove this once we completely switch to cri integration.
|
|
if kl.networkPlugin != nil {
|
|
kl.runtimeState.setNetworkState(kl.networkPlugin.Status())
|
|
}
|
|
}
|
|
|
|
// updatePodCIDR updates the pod CIDR in the runtime state if it is different
|
|
// from the current CIDR.
|
|
func (kl *Kubelet) updatePodCIDR(cidr string) {
|
|
podCIDR := kl.runtimeState.podCIDR()
|
|
|
|
if podCIDR == cidr {
|
|
return
|
|
}
|
|
|
|
// kubelet -> network plugin
|
|
// cri runtime shims are responsible for their own network plugins
|
|
if kl.networkPlugin != nil {
|
|
details := make(map[string]interface{})
|
|
details[network.NET_PLUGIN_EVENT_POD_CIDR_CHANGE_DETAIL_CIDR] = cidr
|
|
kl.networkPlugin.Event(network.NET_PLUGIN_EVENT_POD_CIDR_CHANGE, details)
|
|
}
|
|
|
|
// kubelet -> generic runtime -> runtime shim -> network plugin
|
|
// docker/rkt non-cri implementations have a passthrough UpdatePodCIDR
|
|
if err := kl.GetRuntime().UpdatePodCIDR(cidr); err != nil {
|
|
glog.Errorf("Failed to update pod CIDR: %v", err)
|
|
return
|
|
}
|
|
|
|
glog.Infof("Setting Pod CIDR: %v -> %v", podCIDR, cidr)
|
|
kl.runtimeState.setPodCIDR(cidr)
|
|
}
|
|
|
|
// shapingEnabled returns whether traffic shaping is enabled.
|
|
func (kl *Kubelet) shapingEnabled() bool {
|
|
// Disable shaping if a network plugin is defined and supports shaping
|
|
if kl.networkPlugin != nil && kl.networkPlugin.Capabilities().Has(network.NET_PLUGIN_CAPABILITY_SHAPING) {
|
|
return false
|
|
}
|
|
// This is not strictly true but we need to figure out how to handle
|
|
// bandwidth shaping anyway. If the kubelet doesn't have a networkPlugin,
|
|
// it could mean:
|
|
// a. the kubelet is responsible for bandwidth shaping
|
|
// b. the kubelet is using cri, and the cri has a network plugin
|
|
// Today, the only plugin that understands bandwidth shaping is kubenet, and
|
|
// it doesn't support bandwidth shaping when invoked through cri, so it
|
|
// effectively boils down to letting the kubelet decide how to handle
|
|
// shaping annotations. The combination of (cri + network plugin that
|
|
// handles bandwidth shaping) may not work because of this.
|
|
return true
|
|
}
|
|
|
|
// syncNetworkUtil ensures the network utility are present on host.
|
|
// Network util includes:
|
|
// 1. In nat table, KUBE-MARK-DROP rule to mark connections for dropping
|
|
// Marked connection will be drop on INPUT/OUTPUT Chain in filter table
|
|
// 2. In nat table, KUBE-MARK-MASQ rule to mark connections for SNAT
|
|
// Marked connection will get SNAT on POSTROUTING Chain in nat table
|
|
func (kl *Kubelet) syncNetworkUtil() {
|
|
if kl.iptablesMasqueradeBit < 0 || kl.iptablesMasqueradeBit > 31 {
|
|
glog.Errorf("invalid iptables-masquerade-bit %v not in [0, 31]", kl.iptablesMasqueradeBit)
|
|
return
|
|
}
|
|
|
|
if kl.iptablesDropBit < 0 || kl.iptablesDropBit > 31 {
|
|
glog.Errorf("invalid iptables-drop-bit %v not in [0, 31]", kl.iptablesDropBit)
|
|
return
|
|
}
|
|
|
|
if kl.iptablesDropBit == kl.iptablesMasqueradeBit {
|
|
glog.Errorf("iptables-masquerade-bit %v and iptables-drop-bit %v must be different", kl.iptablesMasqueradeBit, kl.iptablesDropBit)
|
|
return
|
|
}
|
|
|
|
// Setup KUBE-MARK-DROP rules
|
|
dropMark := getIPTablesMark(kl.iptablesDropBit)
|
|
if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubeMarkDropChain); err != nil {
|
|
glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubeMarkDropChain, err)
|
|
return
|
|
}
|
|
if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubeMarkDropChain, "-j", "MARK", "--set-xmark", dropMark); err != nil {
|
|
glog.Errorf("Failed to ensure marking rule for %v: %v", KubeMarkDropChain, err)
|
|
return
|
|
}
|
|
if _, err := kl.iptClient.EnsureChain(utiliptables.TableFilter, KubeFirewallChain); err != nil {
|
|
glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableFilter, KubeFirewallChain, err)
|
|
return
|
|
}
|
|
if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableFilter, KubeFirewallChain,
|
|
"-m", "comment", "--comment", "kubernetes firewall for dropping marked packets",
|
|
"-m", "mark", "--mark", dropMark,
|
|
"-j", "DROP"); err != nil {
|
|
glog.Errorf("Failed to ensure rule to drop packet marked by %v in %v chain %v: %v", KubeMarkDropChain, utiliptables.TableFilter, KubeFirewallChain, err)
|
|
return
|
|
}
|
|
if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableFilter, utiliptables.ChainOutput, "-j", string(KubeFirewallChain)); err != nil {
|
|
glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableFilter, utiliptables.ChainOutput, KubeFirewallChain, err)
|
|
return
|
|
}
|
|
if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableFilter, utiliptables.ChainInput, "-j", string(KubeFirewallChain)); err != nil {
|
|
glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableFilter, utiliptables.ChainInput, KubeFirewallChain, err)
|
|
return
|
|
}
|
|
|
|
// Setup KUBE-MARK-MASQ rules
|
|
masqueradeMark := getIPTablesMark(kl.iptablesMasqueradeBit)
|
|
if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubeMarkMasqChain); err != nil {
|
|
glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubeMarkMasqChain, err)
|
|
return
|
|
}
|
|
if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubePostroutingChain); err != nil {
|
|
glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubePostroutingChain, err)
|
|
return
|
|
}
|
|
if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubeMarkMasqChain, "-j", "MARK", "--set-xmark", masqueradeMark); err != nil {
|
|
glog.Errorf("Failed to ensure marking rule for %v: %v", KubeMarkMasqChain, err)
|
|
return
|
|
}
|
|
if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableNAT, utiliptables.ChainPostrouting,
|
|
"-m", "comment", "--comment", "kubernetes postrouting rules", "-j", string(KubePostroutingChain)); err != nil {
|
|
glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableNAT, utiliptables.ChainPostrouting, KubePostroutingChain, err)
|
|
return
|
|
}
|
|
if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubePostroutingChain,
|
|
"-m", "comment", "--comment", "kubernetes service traffic requiring SNAT",
|
|
"-m", "mark", "--mark", masqueradeMark, "-j", "MASQUERADE"); err != nil {
|
|
glog.Errorf("Failed to ensure SNAT rule for packets marked by %v in %v chain %v: %v", KubeMarkMasqChain, utiliptables.TableNAT, KubePostroutingChain, err)
|
|
return
|
|
}
|
|
}
|
|
|
|
// getIPTablesMark returns the fwmark given the bit
|
|
func getIPTablesMark(bit int) string {
|
|
value := 1 << uint(bit)
|
|
return fmt.Sprintf("%#08x/%#08x", value, value)
|
|
}
|