forked from kubernetes/kubernetes
-
Notifications
You must be signed in to change notification settings - Fork 0
/
kubelet_network.go
290 lines (253 loc) · 12.1 KB
/
kubelet_network.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
/*
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"
"github.com/golang/glog"
"k8s.io/api/core/v1"
clientset "k8s.io/client-go/kubernetes"
runtimeapi "k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
"k8s.io/kubernetes/pkg/kubelet/apis/kubeletconfig"
kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
"k8s.io/kubernetes/pkg/kubelet/network"
kubetypes "k8s.io/kubernetes/pkg/kubelet/types"
utiliptables "k8s.io/kubernetes/pkg/util/iptables"
)
const (
// KubeMarkMasqChain is the mark-for-masquerade chain
// TODO: clean up this logic in kube-proxy
KubeMarkMasqChain utiliptables.Chain = "KUBE-MARK-MASQ"
// KubeMarkDropChain is the mark-for-drop chain
KubeMarkDropChain utiliptables.Chain = "KUBE-MARK-DROP"
// KubePostroutingChain is kubernetes postrouting rules
KubePostroutingChain utiliptables.Chain = "KUBE-POSTROUTING"
// KubeFirewallChain is kubernetes firewall rules
KubeFirewallChain utiliptables.Chain = "KUBE-FIREWALL"
)
// This just exports required functions from kubelet proper, for use by network
// plugins.
// TODO(#35457): get rid of this backchannel to the kubelet. The scope of
// the back channel is restricted to host-ports/testing, and restricted
// to kubenet. No other network plugin wrapper needs it. Other plugins
// only require a way to access namespace information, which they can do
// directly through the methods implemented by criNetworkHost.
type networkHost struct {
kubelet *Kubelet
}
func (nh *networkHost) GetPodByName(name, namespace string) (*v1.Pod, bool) {
return nh.kubelet.GetPodByName(name, namespace)
}
func (nh *networkHost) GetKubeClient() clientset.Interface {
return nh.kubelet.kubeClient
}
func (nh *networkHost) GetRuntime() kubecontainer.Runtime {
return nh.kubelet.GetRuntime()
}
func (nh *networkHost) SupportsLegacyFeatures() bool {
return true
}
// criNetworkHost implements the part of network.Host required by the
// cri (NamespaceGetter). It leechs off networkHost for all other
// methods, because networkHost is slated for deletion.
type criNetworkHost struct {
*networkHost
// criNetworkHost currently support legacy features. Hence no need to support PortMappingGetter
*network.NoopPortMappingGetter
}
// GetNetNS returns the network namespace of the given containerID.
// This method satisfies the network.NamespaceGetter interface for
// networkHost. It's only meant to be used from network plugins
// that are directly invoked by the kubelet (aka: legacy, pre-cri).
// Any network plugin invoked by a cri must implement NamespaceGetter
// to talk directly to the runtime instead.
func (c *criNetworkHost) GetNetNS(containerID string) (string, error) {
return c.kubelet.GetRuntime().GetNetNS(kubecontainer.ContainerID{Type: "", ID: containerID})
}
// NoOpLegacyHost implements the network.LegacyHost interface for the remote
// runtime shim by just returning empties. It doesn't support legacy features
// like host port and bandwidth shaping.
type NoOpLegacyHost struct{}
// GetPodByName always returns "nil, true" for 'NoOpLegacyHost'
func (n *NoOpLegacyHost) GetPodByName(namespace, name string) (*v1.Pod, bool) {
return nil, true
}
// GetKubeClient always returns "nil" for 'NoOpLegacyHost'
func (n *NoOpLegacyHost) GetKubeClient() clientset.Interface {
return nil
}
// GetRuntime always returns "nil" for 'NoOpLegacyHost'
func (n *NoOpLegacyHost) GetRuntime() kubecontainer.Runtime {
return nil
}
// SupportsLegacyFeatures always returns "false" for 'NoOpLegacyHost'
func (n *NoOpLegacyHost) SupportsLegacyFeatures() bool {
return false
}
// effectiveHairpinMode determines the effective hairpin mode given the
// configured mode, container runtime, and whether cbr0 should be configured.
func effectiveHairpinMode(hairpinMode kubeletconfig.HairpinMode, containerRuntime string, networkPlugin string) (kubeletconfig.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 == kubeletconfig.PromiscuousBridge || hairpinMode == kubeletconfig.HairpinVeth {
// Only on docker.
if containerRuntime != kubetypes.DockerContainerRuntime {
glog.Warningf("Hairpin mode set to %q but container runtime is %q, ignoring", hairpinMode, containerRuntime)
return kubeletconfig.HairpinNone, nil
}
if hairpinMode == kubeletconfig.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, kubeletconfig.HairpinVeth)
return kubeletconfig.HairpinVeth, nil
}
} else if hairpinMode != kubeletconfig.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
}
// 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)
}
// 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)
}
// GetPodDNS returns DNS setttings for the pod.
// This function is defined in kubecontainer.RuntimeHelper interface so we
// have to implement it.
func (kl *Kubelet) GetPodDNS(pod *v1.Pod) (*runtimeapi.DNSConfig, error) {
return kl.dnsConfigurer.GetPodDNS(pod)
}