在本章中，我们将直接将 Cilium 安装到 Kubernetes 集群中。
在实验中，我们用到的组件及版本为：
📝Notes:
如前文所述，Cilium 对 Linux Kernel 版本要求很高。1.13.4 推荐 Kernel ≥ 5.10（使用最新 LTS 稳定版 Kernel), 最低 Linux Kernel 得是 4.19.57.
所以我们选择 2 个 OS, 一个只满足最低 Kernel 要求，一个是尽可能新的 Kernel, 看看安装和功能有哪些差别。
Cilium 支持 2 种安装方式：
CLI 工具能让你轻松上手 Cilium，尤其是在刚开始学习时。它直接使用 Kubernetes API 来检查与现有 kubectl 上下文相对应的集群，并为检测到的 Kubernetes 实施选择合适的安装选项。
Helm Chart 方法适用于需要对 Cilium 安装进行精细控制的高级安装和生产环境。它要求你为特定的 Kubernetes 环境手动选择最佳数据路径 (datapath) 和 IPAM 模式。
要安装 Cilium, 最低系统需求如下：
| Cilium 功能 | 最小 Kernel 版本 |
|---|---|
| Bandwidth Manager | >= 5.1 |
| Egress Gateway | >= 5.2 |
| VXLAN Tunnel Endpoint (VTEP) Integration | >= 5.2 |
| WireGuard Transparent Encryption | >= 5.6 |
| Full support for Session Affinity | >= 5.7 |
| BPF-based proxy redirection | >= 5.7 |
| Socket-level LB bypass in pod netns | >= 5.7 |
| L3 devices | >= 5.8 |
| BPF-based host routing | >= 5.10 |
| IPv6 BIG TCP support | >= 5.19 |
首次安装，我们使用 Cilium CLI 方式安装。OS 为：Debian 10, Kernel 4.19 4.19.232, arm64
我们通过 K3s 安装 Kubernetes 集群。具体命令如下：
# Server Node
curl -sfL https://rancher-mirror.rancher.cn/k3s/k3s-install.sh | INSTALL_K3S_MIRROR=cn INSTALL_K3S_EXEC='--write-kubeconfig-mode=644 --flannel-backend=none --disable-network-policy --prefer-bundled-bin' INSTALL_K3S_VERSION=v1.26.6+k3s1 sh -
📝Notes:
几个主流 Linux 发行版发布的 iptables 版本包含一个错误，该错误会导致重复规则的累积，从而对节点的性能和稳定性产生负面影响。有关如何确定你是否受此问题影响，请参阅 issue #3117。
K3s 具有一个可以正常运行的 iptables (v1.8.8) 版本。你可以通过使用--prefer-bundled-bin选项来启动 K3s，或从操作系统中卸载 iptables/nftables 包，从而让 K3s 使用捆绑的 iptables 版本。
版本--prefer-bundled-bin标志从 2022-12 版本开始可用（v1.26.0+k3s1、v1.25.5+k3s1、v1.24.9+k3s1、v1.23.15+k3s1）。
验证：
$ systemctl status k3s
● k3s.service - Lightweight Kubernetes
Loaded: loaded (/etc/systemd/system/k3s.service; enabled; vendor preset: enabled)
Active: active (running)
$ k3s kubectl get node
NAME STATUS ROLES AGE VERSION
linaro-alip NotReady control-plane,master 3d1h v1.26.6+k3s1
🐾注意，由于没有安装 flannel, 也还没开始安装 Cilium, 所以 node 状态应为：NotReady.
CILIUM_CLI_VERSION=$(curl -s https://raw.githubusercontent.com/cilium/cilium-cli/master/stable.txt)
CLI_ARCH=amd64
if [ "$(uname -m)" = "aarch64" ]; then CLI_ARCH=arm64; fi
curl -L --fail --remote-name-all https://github.com/cilium/cilium-cli/releases/download/${CILIUM_CLI_VERSION}/cilium-linux-${CLI_ARCH}.tar.gz{,.sha256sum}
sha256sum --check cilium-linux-${CLI_ARCH}.tar.gz.sha256sum
sudo tar xzvfC cilium-linux-${CLI_ARCH}.tar.gz /usr/local/bin
rm cilium-linux-${CLI_ARCH}.tar.gz{,.sha256sum}
验证：
$ cilium version
cilium-cli: v0.15.2 compiled with go1.20.4 on linux/arm64
cilium image (default): v1.13.4
cilium image (stable): v1.13.4
cilium image (running): 1.13.4
export KUBECONFIG=/etc/rancher/k3s/k3s.yaml
cilium install
通过该命令，cilium 会自动进行一些环境信息的识别，以及参数的选择和判断：
🔮 Auto-detected Kubernetes kind: k3s
✨ Running "k3s" validation checks
✅ Detected k3s version "v1.26.6+k3s1"
ℹ️ Using Cilium version 1.13.4
🔮 Auto-detected cluster name: default
🔮 Auto-detected datapath mode: tunnel
🔮 Auto-detected kube-proxy has been installed
ℹ️ helm template --namespace kube-system cilium cilium/cilium --version 1.13.4 --set
cluster.id=0,cluster.name=default,encryption.nodeEncryption=false,ipam.mode=kubernetes,kubeProxyReplacement=disabled,operator.replicas=1,serviceAccounts.cilium.name=cilium,serviceAccounts.operator.name=cilium-operator,tunnel=vxlan
ℹ️ Storing helm values file in kube-system/cilium-cli-helm-values Secret
🔑 Created CA in secret cilium-ca
🔑 Generating certificates for Hubble...
🚀 Creating Service accounts...
🚀 Creating Cluster roles...
🚀 Creating ConfigMap for Cilium version 1.13.4...
🚀 Creating Agent DaemonSet...
🚀 Creating Operator Deployment...
⌛ Waiting for Cilium to be installed and ready...
验证：
$ cilium status --wait
/¯¯\
/¯¯\__/¯¯\ Cilium: OK
\__/¯¯\__/ Operator: OK
/¯¯\__/¯¯\ Envoy DaemonSet: disabled (using embedded mode)
\__/¯¯\__/ Hubble Relay: disabled
\__/ ClusterMesh: disabled
DaemonSet cilium Desired: 1, Ready: 1/1, Available: 1/1
Deployment cilium-operator Desired: 1, Ready: 1/1, Available: 1/1
Containers: cilium Running: 1
cilium-operator Running: 1
Cluster Pods: 7/7 managed by Cilium
Helm chart version: 1.13.4
Image versions cilium quay.io/cilium/cilium:v1.13.4@sha256:bde8800d61aaad8b8451b10e247ac7bdeb7af187bb698f83d40ad75a38c1ee6b: 1
cilium-operator quay.io/cilium/operator-generic:v1.13.4@sha256:09ab77d324ef4d31f7d341f97ec5a2a4860910076046d57a2d61494d426c6301: 1
运行以下命令验证群集是否具有正确的网络连接：
$ cilium connectivity test --request-timeout 30s --connect-timeout 10s
ℹ️ Monitor aggregation detected, will skip some flow validation steps
✨ [k8s-cluster] Creating namespace for connectivity check...
(...)
---------------------------------------------------------------------------------------------------------------------
📋 Test Report
---------------------------------------------------------------------------------------------------------------------
✅ 69/69 tests successful (0 warnings)
🐾Warning:
在中国安装时，由于网络环境所限，可能部分测试会失败（如访问 1.1.1.1:443).
属于正常情况。
连接性测试需要至少两个 worker node 才能在群集中成功部署。连接性测试 pod 不会在以控制面角色运行的节点上调度。如果您没有为群集配置两个 worker node，连接性测试命令可能会在等待测试环境部署完成时停滞。
查看 Cilium Install 具体启用了哪些功能：
$ kubectl -n kube-system exec ds/cilium -- cilium status
Defaulted container "cilium-agent" out of: cilium-agent, config (init), mount-cgroup (init), apply-sysctl-overwrites (init), mount-bpf-fs (init), clean-cilium-state (init), install-cni-binaries (init)
KVStore: Ok Disabled
Kubernetes: Ok 1.26 (v1.26.6+k3s1) [linux/arm64]
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 1.13.4 (v1.13.4-4061cdfc)
NodeMonitor: Listening for events on 4 CPUs with 64x4096 of shared memory
Cilium health daemon: Ok
IPAM: IPv4: 9/254 allocated from 10.0.0.0/24,
IPv6 BIG TCP: Disabled
BandwidthManager: Disabled
Host Routing: Legacy
Masquerading: IPtables
Controller Status: 48/48 healthy
Proxy Status: No managed proxy redirect
Global Identity Range: min 256, max 65535
Hubble: Ok Current/Max Flows: 4095/4095 (100.00%), Flows/s: 11.68 Metrics: Disabled
Encryption: Disabled
Cluster health: 1/1 reachable (2023-07-19T12:25:40Z)
这里有几个点注意一下：
datapath mode: tunnel: 因为兼容性原因，Cilium 会默认启用 tunnel（基于 vxlan) 的 datapatch 模式，也就是 overlay 网络结构。KubeProxyReplacement: Disabled Cilium 是没有完全替换掉 kube-proxy 的，后面我们会出文章介绍如何实现替换。IPv6 BIG TCP: Disabled 该功能要求 Linux Kernel >= 5.19, 所以在 Kernel 4.19.232 状态为禁用。BandwidthManager: Disabled 该功能要求 Linux Kernel >= 5.1, 所以目前是禁用的Host Routing: Legacy Legacy Host Routing 还是会用到 iptables, 性能较弱；但是 BPF-based host routing 需要 Linux Kernel >= 5.10Masquerading: IPtables IP 伪装有几种方式：基于 eBPF 的，和基于 iptables 的。默认使用基于 iptables, 推荐使用 基于 eBPF 的。Hubble Relay: disabled 默认 Hubble 也是禁用的。Cilium 的最重要的特点就是其性能，所以只要是可以增强性能的，后续会一一介绍如何启用。
$ cilium hubble enable --ui
✨ Patching ConfigMap cilium-config to enable Hubble...
🚀 Creating ConfigMap for Cilium version 1.13.4...
♻️ Restarted Cilium pods
⌛ Waiting for Cilium to become ready before deploying other Hubble component(s)...
🚀 Creating Peer Service...
✨ Generating certificates...
🔑 Generating certificates for Relay...
✨ Deploying Relay...
✨ Deploying Hubble UI and Hubble UI Backend...
⌛ Waiting for Hubble to be installed...
ℹ️ Storing helm values file in kube-system/cilium-cli-helm-values Secret
✅ Hubble was successfully enabled!
验证：
$ cilium status
/¯¯\
/¯¯\__/¯¯\ Cilium: OK
\__/¯¯\__/ Operator: OK
/¯¯\__/¯¯\ Envoy DaemonSet: disabled (using embedded mode)
\__/¯¯\__/ Hubble Relay: OK
\__/ ClusterMesh: disabled
Deployment hubble-ui Desired: 1, Ready: 1/1, Available: 1/1
DaemonSet cilium Desired: 1, Ready: 1/1, Available: 1/1
Deployment cilium-operator Desired: 1, Ready: 1/1, Available: 1/1
Deployment hubble-relay Desired: 1, Ready: 1/1, Available: 1/1
Containers: hubble-ui Running: 1
cilium Running: 1
cilium-operator Running: 1
hubble-relay Running: 1
Cluster Pods: 9/9 managed by Cilium
Helm chart version: 1.13.4
Image versions cilium quay.io/cilium/cilium:v1.13.4@sha256:bde8800d61aaad8b8451b10e247ac7bdeb7af187bb698f83d40ad75a38c1ee6b: 1
cilium-operator quay.io/cilium/operator-generic:v1.13.4@sha256:09ab77d324ef4d31f7d341f97ec5a2a4860910076046d57a2d61494d426c6301: 1
hubble-relay quay.io/cilium/hubble-relay:v1.13.4@sha256:bac057a5130cf75adf5bc363292b1f2642c0c460ac9ff018fcae3daf64873871: 1
hubble-ui quay.io/cilium/hubble-ui:v0.11.0@sha256:bcb369c47cada2d4257d63d3749f7f87c91dde32e010b223597306de95d1ecc8: 1
hubble-ui quay.io/cilium/hubble-ui-backend:v0.11.0@sha256:14c04d11f78da5c363f88592abae8d2ecee3cbe009f443ef11df6ac5f692d839: 1
$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
linaro-alip Ready control-plane,master 3d1h v1.26.6+k3s1
$ kubectl get daemonsets --all-namespaces
NAMESPACE NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
kube-system cilium 1 1 1 1 1 kubernetes.io/os=linux 28h
kube-system svclb-traefik-29b9c193 1 1 1 1 1 <none> 2d23h
$ kubectl get deployments --all-namespaces
NAMESPACE NAME READY UP-TO-DATE AVAILABLE AGE
kube-system local-path-provisioner 1/1 1 1 3d1h
default my-nginx 2/2 2 2 32h
kube-system coredns 1/1 1 1 3d1h
kube-system traefik 1/1 1 1 2d23h
kube-system metrics-server 1/1 1 1 3d1h
kube-system cilium-operator 1/1 1 1 28h
kube-system hubble-relay 1/1 1 1 5m39s
kube-system hubble-ui 1/1 1 1 5m38s
你应该会发现 cilium daemonset 正在集群的所有节点上运行，而 cilium-operator 部署正在单个节点上运行。
恭喜你！🎉🎉🎉你现在已经安装了 Cilium，为 Kubernetes 集群提供连接。
本文我们主要介绍了 Cilium 的快速安装过程。
要安装 Cilium, 需要满足一些基本需求，其中 Cilium 对 Linux Kernel 版本的要求较高。
通过 cilium install, 在 Debian 10, Kernel 4.19.232, arm64 机器上，安装了 K3s v1.26.6+k3s1 和 Cilium 1.13.4, 启用了 Hubble, 并进行了验证。🎉🎉🎉
三人行, 必有我师; 知识共享, 天下为公. 本文由东风微鸣技术博客 EWhisper.cn 编写.