Cilium Dual Stack 双栈特性（转载）

Cilium 双栈特性（转载）

一、环境信息

主机	IP
ubuntu	10.0.0.234

软件	版本
docker	26.1.4
helm	v3.15.0-rc.2
kind	0.18.0
kubernetes	1.23.4
ubuntu os	Ubuntu 22.04.6 LTS
kernel	5.15.0-106

二、`IPV6/IPV4` 双栈

ipv4 ipv6 共存（ DualStack ）有两种方式:

一个网卡上有两个IP地址，一个是 ipv4 ，一个是 ipv6 。标准实现方式。
两个同样功能的网卡接口，一个提供 ipv4 ，一个提供 ipv6 。通过负载均衡机制，将对应地址的请求发送到对应的网卡。

目前 k8s 集群已经支持 ipv4/ipv6 双栈，从 1.21 alpha 版本开始

同样 cilium cni 也对双栈技术做了实现，是一个 inCluster 层面的实现，如果数据流量要进出集群，就需要平台级的实现。

Cilium 的双协议栈 IPv4/IPv6 网络允许为每个 pod 分配 IPv4 和 IPv6 地址，确保与现代 IPv6 系统以及传统 IPv4 应用程序和服务进行无缝通信。对于正在从 IPv4 向 IPv6 过渡的企业，Cilium 的 NAT46/64 支持为其提供了一条轻松过渡的途径。Cilium 的 BGP IPv6 支持可让用户公布其 IPv6 Pod CIDR。这些功能共同提供了可扩展性，使企业做好准备，迎接 IPv6 成为常态而非例外的未来。

三、`Cilium` `Dual Stack` 模式环境搭建

`kind` 配置文件信息

root@kind:~# cat install.sh

#!/bin/bash
date
set -v

# 1.prep noCNI env
cat <<EOF | kind create cluster --name=cilium-dual-stack --image=kindest/node:v1.23.4 --config=-
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
networking:
  # kind 默认使用 rancher cni，cni 我们需要自己创建
  disableDefaultCNI: true
  # 启用双栈功能打开
  ipFamily: dual
  apiServerAddress: 127.0.0.1
nodes:
  - role: control-plane
  - role: worker
  - role: worker

containerdConfigPatches:
- |-
  [plugins."io.containerd.grpc.v1.cri".registry.mirrors."harbor.evescn.com"]
    endpoint = ["https://harbor.evescn.com"]
EOF

# 2.remove taints
controller_node_ip=`kubectl get node -o wide --no-headers | grep -E "control-plane|bpf1" | awk -F " " '{print $6}'`
# kubectl taint nodes $(kubectl get nodes -o name | grep control-plane) node-role.kubernetes.io/master:NoSchedule-
kubectl get nodes -o wide

# 3.install cni
helm repo add cilium https://helm.cilium.io > /dev/null 2>&1
helm repo update > /dev/null 2>&1

helm install cilium cilium/cilium \
  --set k8sServiceHost=$controller_node_ip \
  --set k8sServicePort=6443 \
  --version 1.13.0-rc5 \
  --namespace kube-system \
  --set debug.enabled=true \
  --set debug.verbose=datapath \
  --set monitorAggregation=none \
  --set ipam.mode=kubernetes \
  --set cluster.name=cilium-dual-stack \
  --set kubeProxyReplacement=disabled
  --set tunnel=vxlan \
  --set ipv6.enabled=true

# 4.install necessary tools
for i in $(docker ps -a --format "table {{.Names}}" | grep cilium) 
do
    echo $i
    docker cp /usr/bin/ping $i:/usr/bin/ping
    docker exec -it $i bash -c "sed -i -e 's/jp.archive.ubuntu.com\|archive.ubuntu.com\|security.ubuntu.com/old-releases.ubuntu.com/g' /etc/apt/sources.list"
    docker exec -it $i bash -c "apt-get -y update >/dev/null && apt-get -y install net-tools tcpdump lrzsz bridge-utils >/dev/null 2>&1"
done

--set 参数解释

--set kubeProxyReplacement=disabled
- 含义: 禁用 kube-proxy 替代功能。
- 用途: Cilium 不会替代 kube-proxy 实现服务负载均衡，依旧使用 kube-proxy 实现服务负载均衡。
--set tunnel=vxlan
- 含义: 使用隧道模式。
- 用途: 启用 VXLAN 隧道模式，这是一种网络虚拟化技术，用于在第 2 层数据包上封装第 3 层数据包，实现网络隔离和扩展。
--set ipv6.enabled=true
- 含义: 启用 IPv6 支持。
- 用途: 启用后网卡会配置 IPv6 地址信息。

安装 k8s 集群和 cilium 服务

root@kind:~# ./install.sh

Creating cluster "cilium-dual-stack" ...
 ✓ Ensuring node image (kindest/node:v1.23.4) 🖼
 ✓ Preparing nodes 📦 📦 📦  
 ✓ Writing configuration 📜 
 ✓ Starting control-plane 🕹️ 
 ✓ Installing StorageClass 💾 
 ✓ Joining worker nodes 🚜 
Set kubectl context to "kind-cilium-dual-stack"
You can now use your cluster with:

kubectl cluster-info --context kind-cilium-dual-stack

Have a question, bug, or feature request? Let us know! https://kind.sigs.k8s.io/#community 🙂

`cilium` 配置信息

root@kind:~# kubectl -n kube-system exec -it ds/cilium -- cilium status

KVStore:                 Ok   Disabled
Kubernetes:              Ok   1.23 (v1.23.4) [linux/amd64]
Kubernetes APIs:         ["cilium/v2::CiliumClusterwideNetworkPolicy", "cilium/v2::CiliumEndpoint", "cilium/v2::CiliumNetworkPolicy", "cilium/v2::CiliumNode", "core/v1::Namespace", "core/v1::Node", "core/v1::Pods", "core/v1::Service", "discovery/v1::EndpointSlice", "networking.k8s.io/v1::NetworkPolicy"]
KubeProxyReplacement:    Disabled   
Host firewall:           Disabled
CNI Chaining:            none
CNI Config file:         CNI configuration file management disabled
Cilium:                  Ok   1.13.0-rc5 (v1.13.0-rc5-dc22a46f)
NodeMonitor:             Listening for events on 8 CPUs with 64x4096 of shared memory
Cilium health daemon:    Ok   
# IPAM 中不仅有 IPv4 地址范围，还有 IPv6 地址范围
IPAM:                    IPv4: 6/254 allocated from 10.244.1.0/24, IPv6: 6/18446744073709551614 allocated from fd00:10:244:1::/64
IPv6 BIG TCP:            Disabled
BandwidthManager:        Disabled
Host Routing:            Legacy
Masquerading:            IPTables [IPv4: Enabled, IPv6: Enabled]
Controller Status:       34/34 healthy
Proxy Status:            OK, ip 10.244.1.154, 0 redirects active on ports 10000-20000
Global Identity Range:   min 256, max 65535
Hubble:                  Ok   Current/Max Flows: 4095/4095 (100.00%), Flows/s: 11.23   Metrics: Disabled
Encryption:              Disabled
Cluster health:          3/3 reachable   (2024-07-12T07:00:21Z)

`k8s` 集群安装 `Pod` 测试网络

# cat cni.yaml

apiVersion: apps/v1
kind: DaemonSet
#kind: Deployment
metadata:
  labels:
    app: cni
  name: cni
spec:
  #replicas: 1
  selector:
    matchLabels:
      app: cni
  template:
    metadata:
      labels:
        app: cni
    spec:
      containers:
      - image: harbor.dayuan1997.com/devops/nettool:0.9
        name: nettoolbox
        securityContext:
          privileged: true

---
apiVersion: v1
kind: Service
metadata:
  name: cni
spec:
  ipFamilyPolicy: PreferDualStack
  ipFamilies:
  - IPv6
  - IPv4
  ports:
  - port: 80
    targetPort: 80
    protocol: TCP
    nodePort: 30000
  type: NodePort
  selector:
    app: cni

root@kind:~# kubectl apply -f cni.yaml
daemonset.apps/cni created
service/serversvc created

查看安装服务信息

root@kind:~# kubectl get pods -o wide
NAME        READY   STATUS    RESTARTS   AGE     IP             NODE                        NOMINATED NODE   READINESS GATES
cni-7t9p4   1/1     Running   0          2m35s   10.244.1.233   cilium-dual-stack-worker    <none>           <none>
cni-8qgcs   1/1     Running   0          2m35s   10.244.2.245   cilium-dual-stack-worker2   <none>           <none>

确认 `IPv4 IPv6` 双栈启用成功

查看 POD 信息

root@kind:~# kubectl exec -it cni-7t9p4 -- bash
cni-7t9p4~$ ip a l
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
18: eth0@if19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 4e:5b:57:45:63:3b brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.244.1.233/32 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fd00:10:244:1::4749/128 scope global nodad 
       valid_lft forever preferred_lft forever
    inet6 fe80::4c5b:57ff:fe45:633b/64 scope link 
       valid_lft forever preferred_lft forever

eth0 网卡同时存在 IPv4 地址 10.244.1.233 和 IPv6 地址 fd00:10:244:1::4749 ， pod IPv4 IPv6 双栈启用成功

查看 SVC 信息

root@KinD:~# kubectl get svc
NAME         TYPE        CLUSTER-IP         EXTERNAL-IP   PORT(S)        AGE
cni          NodePort    fd00:10:96::f38d   <none>        80:30000/TCP   6m44s
kubernetes   ClusterIP   10.96.0.1          <none>        443/TCP        58m
serversvc    NodePort    10.96.58.99        <none>        80:32000/TCP   53m

root@KinD:~# kubectl get svc cni -o yaml
apiVersion: v1
kind: Service
metadata:
  annotations:
    ......
  creationTimestamp: "2024-07-12T07:08:05Z"
  name: cni
  namespace: default
  resourceVersion: "8306"
  uid: 47a50c0e-d595-48f1-8574-59328412be13
spec:
  clusterIP: fd00:10:96::f38d
  clusterIPs:
  - fd00:10:96::f38d
  - 10.96.86.244
  externalTrafficPolicy: Cluster
  internalTrafficPolicy: Cluster
  ipFamilies:
  - IPv6
  - IPv4
  ipFamilyPolicy: PreferDualStack
  ports:
  - nodePort: 30000
    port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: cni
  sessionAffinity: None
  type: NodePort
status:
  loadBalancer: {}

svc 网卡同时存在 IPv4 地址 10.96.86.244 和 IPv6 地址 fd00:10:96::f38d ， svc IPv4 IPv6 双栈启用成功

svc 的 IPv4 和 IPv6 地址的解析验证

root@KinD:~# kubectl exec -it cni-7t9p4 -- bash
 
cni-7t9p4~$ nslookup -type=A cni
Server:         10.96.0.10
Address:        10.96.0.10#53

Name:   cni.default.svc.cluster.local
Address: 10.96.86.244

cni-7t9p4~$ nslookup -type=AAAA cni
Server:         10.96.0.10
Address:        10.96.0.10#53

Name:   cni.default.svc.cluster.local
Address: fd00:10:96::f38d

-type=A 解析 cni svc 的 ipv4 地址，解析结果: 10.96.86.244 ，同配置文件信息一致
-type=AAAA 解析 cni svc 的 ipv6 地址，解析结果: fd00:10:96::f38d ，同配置文件信息一致

`Cilium` `Dual Stack` 模式分析

IPv4 模式下 pod 内的 IP 路由信息

root@KinD:~# kubectl exec -it cni-7t9p4 -- ip a l
18: eth0@if19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 4e:5b:57:45:63:3b brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.244.1.233/32 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fd00:10:244:1::4749/128 scope global nodad 
       valid_lft forever preferred_lft forever
    inet6 fe80::4c5b:57ff:fe45:633b/64 scope link 
       valid_lft forever preferred_lft forever

root@kind:~# # kubectl exec -it cni-7t9p4 -- ip r s
default via 10.244.1.154 dev eth0 mtu 1450 
10.244.1.154 dev eth0 scope link

pod 出网需要经过 eth0 网卡，下一跳地址 10.244.1.154 为 node 节点上的 cilium_host 网卡

root@KinD:~# kubectl get pods -owide
NAME        READY   STATUS    RESTARTS   AGE   IP             NODE                        NOMINATED NODE   READINESS GATES
cni-7t9p4   1/1     Running   0          29m   10.244.1.233   cilium-dual-stack-worker    <none>           <none>
cni-8qgcs   1/1     Running   0          29m   10.244.2.245   cilium-dual-stack-worker2   <none>           <none>

root@KinD:~# lo cilium-dual-stack-worker ip a l
3: cilium_host@cilium_net: <BROADCAST,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 32:ed:4d:67:b2:e1 brd ff:ff:ff:ff:ff:ff
    inet 10.244.1.154/32 scope link cilium_host
       valid_lft forever preferred_lft forever
    inet6 fc00:f853:ccd:e793::4/128 scope global 
       valid_lft forever preferred_lft forever
    inet6 fe80::30ed:4dff:fe67:b2e1/64 scope link 
       valid_lft forever preferred_lft forever

# cni-7t9p4 POD eth0 的 veth pair 网卡信息
19: lxc237a31216c0f@if18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether a2:79:14:47:80:b3 brd ff:ff:ff:ff:ff:ff link-netns cni-7635120a-f51b-728d-4cbd-91d3c61c0093
    inet6 fe80::a079:14ff:fe47:80b3/64 scope link 
       valid_lft forever preferred_lft forever

IPv6 模式下 pod 内的路由规则

root@KinD:~# kubectl exec -it cni-7t9p4 -- ip -6 r s
fd00:10:244:1::22f1 dev eth0 metric 1024 pref medium
fd00:10:244:1::4749 dev eth0 proto kernel metric 256 pref medium
fe80::/64 dev eth0 proto kernel metric 256 pref medium
default via fd00:10:244:1::22f1 dev eth0 metric 1024 mtu 1450 pref medium

root@KinD:~# kubectl exec -it cni-7t9p4 -- ip -6 n s
fd00:10:244:1::22f1 dev eth0 lladdr a2:79:14:47:80:b3 router STALE

它的下一跳所在的地址 fd00:10:244:1::22f1 ，查看 ip -6 n s 发现 fd00:10:244:1::22f1 地址对应的 mac 地址为 a2:79:14:47:80:b3 ，此地址为 cilium-dual-stack-worker 节点 19: lxc237a31216c0f@if18 网卡 mac 地址，但是此网卡没有 fd00:10:244:1::22f1 IPv6 地址
此处类似于 calico 的 169.254.1.1 ，这个地址不一定要有，但是数据包往上面发的时候，只要有一个hook能劫持，并且让其他网卡回复对应的mac地址就行了。

IPv6 模式下的 ping 测

cni-7t9p4~$ ip a l
18: eth0@if19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 4e:5b:57:45:63:3b brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.244.1.233/32 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fd00:10:244:1::4749/128 scope global nodad 
       valid_lft forever preferred_lft forever
    inet6 fe80::4c5b:57ff:fe45:633b/64 scope link 
       valid_lft forever preferred_lft forever

cni-8qgcs~$ ip a l
11: eth0@if12: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether b6:61:48:ae:63:f5 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.244.2.245/32 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fd00:10:244:2::9461/128 scope global nodad 
       valid_lft forever preferred_lft forever
    inet6 fe80::b461:48ff:feae:63f5/64 scope link 
       valid_lft forever preferred_lft forever

cni-7t9p4 IPv6 地址: fd00:10:244:1::4749
cni-8qgcs IPv6 地址: fd00:10:244:2::9461

root@KinD:~# kubectl exec -it cni-7t9p4 -- ping6 -c 1 fd00:10:244:2::9461
PING fd00:10:244:2::9461 (fd00:10:244:2::9461): 56 data bytes
64 bytes from fd00:10:244:2::9461: seq=0 ttl=63 time=0.838 ms

--- fd00:10:244:2::9461 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.838/0.838/0.838 ms

cni-7t9p4 eth0 网卡抓包分析数据包

cni-7t9p4~$tcpdump -pne -i eth0 
tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), snapshot length 262144 bytes

07:44:28.594775 4e:5b:57:45:63:3b > 33:33:ff:00:22:f1, ethertype IPv6 (0x86dd), length 86: fe80::4c5b:57ff:fe45:633b > ff02::1:ff00:22f1: ICMP6, neighbor solicitation, who has fd00:10:244:1::22f1, length 32
07:44:28.594812 a2:79:14:47:80:b3 > 4e:5b:57:45:63:3b, ethertype IPv6 (0x86dd), length 86: fd00:10:244:1::22f1 > fe80::4c5b:57ff:fe45:633b: ICMP6, neighbor advertisement, tgt is fd00:10:244:1::22f1, length 32
07:44:28.594846 4e:5b:57:45:63:3b > 33:33:ff:00:22:f1, ethertype IPv6 (0x86dd), length 86: fd00:10:244:1::4749 > ff02::1:ff00:22f1: ICMP6, neighbor solicitation, who has fd00:10:244:1::22f1, length 32
07:44:28.594851 a2:79:14:47:80:b3 > 4e:5b:57:45:63:3b, ethertype IPv6 (0x86dd), length 86: fd00:10:244:1::22f1 > fd00:10:244:1::4749: ICMP6, neighbor advertisement, tgt is fd00:10:244:1::22f1, length 32
07:44:28.594856 4e:5b:57:45:63:3b > a2:79:14:47:80:b3, ethertype IPv6 (0x86dd), length 118: fd00:10:244:1::4749 > fd00:10:244:2::9461: ICMP6, echo request, id 44, seq 0, length 64
07:44:28.595463 a2:79:14:47:80:b3 > 4e:5b:57:45:63:3b, ethertype IPv6 (0x86dd), length 118: fd00:10:244:2::9461 > fd00:10:244:1::4749: ICMP6, echo reply, id 44, seq 0, length 64

源 mac : 4e:5b:57:45:63:3b 为 cni-7t9p4 eth0 网卡 mac 地址，目标 mac : a2:79:14:47:80:b3 为 cni-7t9p4 eth0 网卡对应的 lxc 网卡 mac 地址
源 IPv6 : fd00:10:244:1::4749 为 cni-7t9p4 eth0 网卡 IPv6 地址，目标 IPv6 : fd00:10:244:2::9461 为目标 pod 的 IPv6 地址
所以即使在 pod 内查看 IPv6 的路由规则，找不到对应的下一跳位置，也不影响数据报文的封装。
类似于 calico 的 169.254.1.1 ，这个地址不一定要有，但是数据包往上面发的时候，只要有一个 hook 能劫持，并且让其他网卡回复对应的 mac 地址就行了。这样在封装报文的时候: srcMac srcIP，dstMac，dstIP 都具备了，这样一个数据包才能完整的发送出去。
整个流程差不多就是根据容器内IPv6的下一跳抓包找到对应的mac地址，然后根据mac地址的来源做一个推理。

cni-7t9p4 POD 所在 node 节点 eth0 网卡抓包分析数据包

root@cilium-dual-stack-worker:/# tcpdump -pne -i eth0 -w /tmp/1.cap
root@cilium-dual-stack-worker:/# sz /tmp/1.cap

request 包中内层包中源 mac : 4e:5b:57:45:63:3b 为 cni-7t9p4 eth0 网卡 mac 地址，目标 mac : a2:79:14:47:80:b3 为 cni-7t9p4 eth0 网卡对应的 lxc 网卡 mac 地址，内层包中源 IPv6 : fd00:10:244:1::4749 为 cni-7t9p4 eth0 网卡 IPv6 地址，目标 IPv6 : fd00:10:244:2::9461 为目标 pod 的 IPv6 地址，同 POD 节点 eth0 网卡信息
request 包中外层包中使用 node 节点信息，封装 vxlan 信息完成数据包转发

reply 包中内层包中源 mac 目标 mac 信息不同于 request 包，分析这 2 个地址应该为目标 POD eth0 网卡与其对于的 veth pair 网卡对于 mac 信息

IPv6 的优点
- 一个数据包如果到达IP层才能感知可以丢包，但是 IPv6 在二层就能感知到，不是自己的包就可以丢掉。
- 提供了更多的IP地址，但是复杂性也增加了。

六、转载博客

https://bbs.huaweicloud.com/blogs/417890

posted @ 2024-07-12 16:21 evescn 阅读(70) 评论(0) 编辑收藏举报

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Cilium Dual Stack 双栈特性（转载）

Cilium 双栈特性（转载）

一、环境信息

二、IPV6/IPV4 双栈

三、Cilium Dual Stack 模式环境搭建

kind 配置文件信息

cilium 配置信息

k8s 集群安装 Pod 测试网络

确认 IPv4 IPv6 双栈启用成功

Cilium Dual Stack 模式分析