kubeasz/docs/06.cilium.md

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# 06-安装cilium网络组件
`cilium` 是一个革新的网络与安全组件;基于 linux 内核新技术--`BPF`,它可以透明、零侵入地实现服务间安全策略与可视化,主要优势如下:
- 支持L3/L4, L7(如HTTP/gRPC/Kafka)的安全策略
- 支持基于安全ID而不是地址+端口的传统防火墙策略
- 支持基于Overlay或Native Routing的扁平多节点pod网络
- Overlay VXLAN 方式类似于 flannel 的VXLAN后端
- 高性能负载均衡支持DSR
- 支持事件、策略跟踪和监控集成
## 开始使用 cilium
以下为简要翻译 `cilium doc`上的一个应用示例[原文](http://docs.cilium.io/en/stable/gettingstarted/minikube/#step-2-deploy-the-demo-application)部署在单节点k8s 环境的实践。
### 0.升级内核并重启
- Linux kernel >= 4.9.17,请阅读文档[升级内核](guide/kernel_upgrade.md)
- etcd >= 3.1.0 or consul >= 0.6.4
### 1.选择cilium网络后安装k8s(allinone)
- 参考[快速指南](quickStart.md),设置 ansible hosts 文件中变量 `CLUSTER_NETWORK="cilium"`
### 2.部署示例应用
官方文档用几个`pod/svc` 抽象一个有趣的应用场景星战迷星战中帝国方建造了被称为“终极武器”的“死星”它是一个卫星大小的战斗空间站它的核心是使用凯伯晶体Kyber Crystal的超级激光炮剧中它的首秀就以完全火力摧毁了“杰达圣城”Jedha。下面将用运行于 k8s上的 pod/svc/cilium 等模拟“死星“的一个“飞船登陆”系统安全策略设计。
- deploy/deathstar作为控制整个“死星”的飞船登陆管理系统它暴露一个SVC提供HTTP REST 接口给飞船请求登陆使用;
- pod/tiefighter作为“帝国”方的常规战斗飞船它会调用上述 HTTP 接口,请求登陆“死星”;
- pod/xwing作为“盟军”方的飞行舰它也尝试调用 HTTP 接口,请求登陆“死星”;
![cilium_http_gsg](../pics/cilium_http_gsg.jpg)
根据文件[http-sw-app.yaml](..//roles/cilium/files/star_war_example/http-sw-app.yaml) 创建 `$ kubectl create -f http-sw-app.yaml` 后,验证如下:
``` bash
$ kubectl get pods,svc
NAME READY STATUS RESTARTS AGE
pod/deathstar-5fc7c7795d-djf2q 1/1 Running 0 4h
pod/deathstar-5fc7c7795d-hrgst 1/1 Running 0 4h
pod/tiefighter 1/1 Running 0 4h
pod/xwing 1/1 Running 0 4h
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/deathstar ClusterIP 10.68.242.130 <none> 80/TCP 4h
service/kubernetes ClusterIP 10.68.0.1 <none> 443/TCP 5h
```
每个 POD 在 `cilium` 中都表示为 `Endpoint`,初始每个 `Endpoint` 的”进出安全策略“状态均为 `Disabled`,如下:(已省略部分无关 POD 信息)
``` bash
$ kubectl exec -n kube-system cilium-6t5vx -- cilium endpoint list
ENDPOINT POLICY (ingress) POLICY (egress) IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT ENFORCEMENT
643 Disabled Disabled 31371 k8s:class=deathstar f00d::ac14:0:0:283 172.20.0.246 ready
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
1011 Disabled Disabled 31371 k8s:class=deathstar f00d::ac14:0:0:3f3 172.20.0.63 ready
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
32030 Disabled Disabled 5350 k8s:class=tiefighter f00d::ac14:0:0:7d1e 172.20.0.201 ready
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
45943 Disabled Disabled 14309 k8s:class=xwing f00d::ac14:0:0:b377 172.20.0.189 ready
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=alliance
52035 Disabled Disabled 4 reserved:health f00d::ac14:0:0:cb43 172.20.0.92 ready
```
### 3.检查初始状态
当然“死星”应该只允许“帝国”的飞船着陆,因为没有应用任何策略,所以初始状态下“帝国”和“联盟”的飞船都可以登陆,如下测试:
``` bash
$ kubectl exec xwing -- curl -s -XPOST deathstar.default.svc.cluster.local/v1/request-landing
Ship landed # 成功着陆
$ kubectl exec tiefighter -- curl -s -XPOST deathstar.default.svc.cluster.local/v1/request-landing
Ship landed # 成功着陆
```
### 4.应用 L3/L4 策略
现在我们应用策略,仅让带有标签 `org=empire`的飞船登陆“死星”;那么带有标签 `org=alliance`的“联盟”飞船将禁止登陆这个就是我们熟悉的传统L3/L4 防火墙策略,并跟踪连接(会话)状态;
![cilium_http_l3_l4_gsg](../pics/cilium_http_l3_l4_gsg.jpg)
根据文件[sw_l3_l4_policy.yaml](..//roles/cilium/files/star_war_example/sw_l3_l4_policy.yaml) 创建 `$ kubectl apply -f sw_l3_l4_policy.yaml` 后,验证如下:
``` bash
$ kubectl exec tiefighter -- curl -s -XPOST deathstar.default.svc.cluster.local/v1/request-landing
Ship landed # 成功着陆
$ kubectl exec xwing -- curl -s -XPOST deathstar.default.svc.cluster.local/v1/request-landing
# 失败超时
```
### 5.查看安全策略
再次执行 `cilium endpoint list`,可以看到标签带`deathstar`的 POD 已经应用了 `Ingress`方向的策略:
``` bash
# kubectl exec -n kube-system cilium-6t5vx -- cilium endpoint list
ENDPOINT POLICY (ingress) POLICY (egress) IDENTITY LABELS (source:key[=value]) IPv6 IPv4 STATUS
ENFORCEMENT ENFORCEMENT
643 Enabled Disabled 31371 k8s:class=deathstar f00d::ac14:0:0:283 172.20.0.246 ready
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
1011 Enabled Disabled 31371 k8s:class=deathstar f00d::ac14:0:0:3f3 172.20.0.63 ready
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
32030 Disabled Disabled 5350 k8s:class=tiefighter f00d::ac14:0:0:7d1e 172.20.0.201 ready
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=empire
45943 Disabled Disabled 14309 k8s:class=xwing f00d::ac14:0:0:b377 172.20.0.189 ready
k8s:io.cilium.k8s.policy.serviceaccount=default
k8s:io.kubernetes.pod.namespace=default
k8s:org=alliance
52035 Disabled Disabled 4 reserved:health f00d::ac14:0:0:cb43 172.20.0.92 ready
```
查看具体策略内容 `kubectl describe cnp rule1`
### 6. L7 安全策略
上述的策略可以进行简单的安全防护了,但是“死星”的这个系统还有很多复杂的功能;比如它还提供了一个内部维护接口,如果被不合理调用将带来严重灾难性后果,也许“联盟”勇士劫持了一架“帝国”飞船正在进行这个任务(虽然我们内心希望他能够成功摧毁“死星”)。不幸的是“死星”系统设计者考虑到这个风险,它有办法严格限制每架飞船能够请求的权限。
没有限制飞船请求权限时,如下运行:
``` bash
$ kubectl exec tiefighter -- curl -s -XPUT deathstar.default.svc.cluster.local/v1/exhaust-port
Panic: deathstar exploded
goroutine 1 [running]:
main.HandleGarbage(0x2080c3f50, 0x2, 0x4, 0x425c0, 0x5, 0xa)
/code/src/github.com/empire/deathstar/
temp/main.go:9 +0x64
main.main()
/code/src/github.com/empire/deathstar/
temp/main.go:5 +0x85
```
![cilium_http_l3_l4_l7_gsg](../pics/cilium_http_l3_l4_l7_gsg.jpg)
限制L7 的安全策略,根据文件[sw_l3_l4_l7_policy.yaml](..//roles/cilium/files/star_war_example/sw_l3_l4_l7_policy.yaml) 创建 `$ kubectl apply -f sw_l3_l4_policy.yaml` 后,验证如下:
``` bash
$ kubectl exec tiefighter -- curl -s -XPOST deathstar.default.svc.cluster.local/v1/request-landing
Ship landed
$ kubectl exec tiefighter -- curl -s -XPUT deathstar.default.svc.cluster.local/v1/exhaust-port
Access denied
```
我们同样可以使用 `kubectl desribe cnp`检查更新的策略,或者使用 `cilium` 命令行:
``` bash
$ kubectl exec -n kube-system cilium-6t5vx -- cilium policy get
[
{
"endpointSelector": {
"matchLabels": {
"any:class": "deathstar",
"any:org": "empire",
"k8s:io.kubernetes.pod.namespace": "default"
}
},
"ingress": [
{
"fromEndpoints": [
{
"matchLabels": {
"any:org": "empire",
"k8s:io.kubernetes.pod.namespace": "default"
}
}
],
"toPorts": [
{
"ports": [
{
"port": "80",
"protocol": "TCP"
}
],
"rules": {
"http": [
{
"path": "/v1/request-landing",
"method": "POST"
}
]
}
}
]
}
],
"labels": [
{
"key": "io.cilium.k8s.policy.name",
"value": "rule1",
"source": "k8s"
},
{
"key": "io.cilium.k8s.policy.namespace",
"value": "default",
"source": "k8s"
}
]
}
]
Revision: 267
```
我们看到 `cilium` 可以实现 `7层 HTTP `协议的请求方法GET/PUT/POST等、路径/v1/request-landing等等安全策略另外它还可以防护其他应用Kafka, gRPC, Elasticsearch可以去官网文档示例学习
## 参考资料
- [cilium github](https://github.com/cilium/cilium)
- [cilium doc](http://docs.cilium.io)