diff --git a/.vuepress/config-sidebar.js b/.vuepress/config-sidebar.js index 3ace6e2..f5ef540 100644 --- a/.vuepress/config-sidebar.js +++ b/.vuepress/config-sidebar.js @@ -232,7 +232,15 @@ module.exports = { 'k8s-intermediate/service/connecting', 'k8s-intermediate/service/ingress', 'k8s-intermediate/service/cni', - 'k8s-intermediate/service/np' + { + title: '网络策略', + collapsable: true, + children: [ + 'k8s-intermediate/service/np', + 'k8s-intermediate/service/np-default', + 'k8s-intermediate/service/np-example', + ] + }, ] }, { diff --git a/.vuepress/public/statics/learning/svc/network-policy.yaml b/.vuepress/public/statics/learning/svc/network-policy.yaml new file mode 100644 index 0000000..89ee988 --- /dev/null +++ b/.vuepress/public/statics/learning/svc/network-policy.yaml @@ -0,0 +1,13 @@ +apiVersion: networking.k8s.io/v1 +kind: NetworkPolicy +metadata: + name: access-nginx +spec: + podSelector: + matchLabels: + app: nginx + ingress: + - from: + - podSelector: + matchLabels: + access: "true" diff --git a/learning/k8s-intermediate/service/np-default.md b/learning/k8s-intermediate/service/np-default.md new file mode 100644 index 0000000..f8721b4 --- /dev/null +++ b/learning/k8s-intermediate/service/np-default.md @@ -0,0 +1,95 @@ +--- +vssueId: 158 +layout: LearningLayout +description: Kubernetes中_网络策略定义了一组Pod是否允许相互通信_或者与网络中的其他端点endpoint通信_本文描述了K8S集群中默认的网络策略 +meta: + - name: keywords + content: Kubernetes教程,K8S教程,Kubernetes Network Policies, K8S 网络策略 +--- + +# Network Policies - Default + + + +> 参考文档: [Network Policies](https://kubernetes.io/docs/concepts/services-networking/network-policies/) + +默认情况下,如果名称空间中没有配置 NetworkPolicy,则该名称空间中,所有Pod的所有入方向流量和所有出方向流量都是被允许的。本文列举了几个例子,可以用来改变名称空间中默认的网络策略 + + + +## 默认拒绝所有的入方向流量 + +在名称空间中创建下面的 NetworkPolicy,该 NetworkPolicy: +* 选中所有的 Pod +* 不允许任何入方向的流量 + +``` yaml +apiVersion: networking.k8s.io/v1 +kind: NetworkPolicy +metadata: + name: default-deny +spec: + podSelector: {} + policyTypes: + - Ingress +``` + +此 NetworkPolicy 将确保名称空间中所有的入方向流量都被限制,同时,不改变出方向的流量。 + +## 默认允许所有的入方向流量 + +在名称空间中创建下面的 NetworkPolicy,该 NetworkPolicy 允许名称空间中所有 Pod 的所有入方向网络流量 + +``` yaml +apiVersion: networking.k8s.io/v1 +kind: NetworkPolicy +metadata: + name: allow-all +spec: + podSelector: {} + ingress: + - {} + policyTypes: + - Ingress +``` + +## 默认拒绝所有出方向流量 + +在名称空间中创建下面的 NetworkPolicy,该 NetworkPolicy 禁止名称空间中所有 Pod 的所有出方向网络流量 + +``` yaml +apiVersion: networking.k8s.io/v1 +kind: NetworkPolicy +metadata: + name: allow-all +spec: + podSelector: {} + egress: + - {} + policyTypes: + - Egress +``` + +## 默认拒绝所有入方向和出方向的网络流量 + +在名称空间中创建下面的 NetworkPolicy,该 NetworkPolicy 禁止名称空间中所有 Pod 的所有入方向流量和所有出方向流量 + +``` yaml +apiVersion: networking.k8s.io/v1 +kind: NetworkPolicy +metadata: + name: default-deny +spec: + podSelector: {} + policyTypes: + - Ingress + - Egress +``` + +## SCTP 支持 + +**FEATURE STATE:** `Kubernetes v1.12` alpha + +在 Kubernetes 中启用 `SCTPSupport` 特性,可以在 `NetworkPolicy` 的 `protocal` 字段中使用 SCTP 这个选项,该特性为 alpha 状态。向 apiserver 的启动参数中添加 `--feature-gates=SCTPSupport=true,...` 可以激活该特性。 + +使用此特性时,您所用的网络插件需要支持 SCTP,请查询网络插件相关的文档。 diff --git a/learning/k8s-intermediate/service/np-example.md b/learning/k8s-intermediate/service/np-example.md new file mode 100644 index 0000000..4202ecc --- /dev/null +++ b/learning/k8s-intermediate/service/np-example.md @@ -0,0 +1,145 @@ +--- +vssueId: 158 +layout: LearningLayout +description: Kubernetes中_网络策略定义了一组Pod是否允许相互通信_或者与网络中的其他端点endpoint通信_本文描述了几个在K8S集群的名称空间中创建NetworkPolicy的例子 +meta: + - name: keywords + content: Kubernetes教程,K8S教程,Kubernetes Network Policies, K8S 网络策略 +--- + +# Network Policies - Example + + + +> 参考文档: [Declare Network Policy](https://kubernetes.io/docs/tasks/administer-cluster/declare-network-policy/) + +本文描述了如何在 Kubernetes 集群中通过创建 NetworkPolicy 的方式来声明网络策略,以管理 Pod 之间的网络通信流量。 + +[[TOC]] + + + +## 前提条件 + +您已经安装了 Kubernetes 集群,如果没有,请参考文档 [安装Kubernetes单Master节点](/install/install-k8s.html) + +您可以使用 kubectl 访问您的集群,请参考文档 [安装Kubectl](/install/install-kubectl.html) + +请确保您使用的网络插件支持 Network Policy,如下的网络插件都是可以的: + +* [Calico](https://kubernetes.io/docs/tasks/administer-cluster/network-policy-provider/calico-network-policy/) 如果您按照 [安装Kubernetes单Master节点](/install/install-k8s.html) 安装的集群,默认是 calico 网络插件 +* [Cilium](https://kubernetes.io/docs/tasks/administer-cluster/network-policy-provider/cilium-network-policy/) +* [Kube-router](https://kubernetes.io/docs/tasks/administer-cluster/network-policy-provider/kube-router-network-policy/) +* [Romana](https://kubernetes.io/docs/tasks/administer-cluster/network-policy-provider/romana-network-policy/) +* [Weave Net](https://kubernetes.io/docs/tasks/administer-cluster/network-policy-provider/weave-network-policy/) + +::: tip +按字母顺序排序,不代表推荐顺序。本文中的例子对上述所有网络插件都有效 +::: + +## 创建一个Deployment并配置Service + +* 创建一个 `nginx` Deployment 用于演示 Kubernetes 的 NetworkPolicy: + + ``` sh + kubectl create deployment nginx --image=nginx + ``` + 输出结果 + ``` + deployment.apps/nginx created + ``` + +* 通过Service暴露该Deployment + + ``` sh + kubectl expose deployment nginx --port=80 + ``` + 输出结果 + ``` + service/nginx exposed + ``` + +* 查询结果 + ``` sh + kubectl get svc,pod + ``` + 输出结果 + ``` + NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE + service/kubernetes 10.100.0.1 443/TCP 46m + service/nginx 10.100.0.16 80/TCP 33s + + NAME READY STATUS RESTARTS AGE + pod/nginx-701339712-e0qfq 1/1 Running 0 35s + ``` + +## 从另外一个pod访问Service + +默认是可以从另外一个Pod访问 `nginx` Service 的。下面的方法可以执行此测试: + +在 `default` 名称空间中创建 busybox 容器,并执行 `wget` 命令: + +``` sh +kubectl run --generator=run-pod/v1 busybox --rm -ti --image=busybox -- /bin/sh +``` + +请按照下面的例子,在命令行中执行 `wget --spider --timeout=1 nginx` +``` +Waiting for pod default/busybox-472357175-y0m47 to be running, status is Pending, pod ready: false + +Hit enter for command prompt + +/ # wget --spider --timeout=1 nginx +Connecting to nginx (10.100.0.16:80) +/ # +``` + +## 限制对nginx的访问 + +下面的 `NetworkPolicy` 可以声明:只有带 `access=true` 标签的 Pod 可以访问 `nginx` 服务: + +<<< @/.vuepress/public/statics/learning/svc/network-policy.yaml + +* 执行命令以创建该 NetworkPolicy: + ``` sh + kubectl apply -f https://kuboard.cn/statics/learning/svc/network-policy.yaml + ``` + 输出结果如下: + ``` + networkpolicy.networking.k8s.io/access-nginx created + ``` + +## 从不带标签的Pod访问nginx服务 + +如果从不带标签的 Pod 访问该 nginx 服务,请求将超时: +``` sh +kubectl run --generator=run-pod/v1 busybox --rm -ti --image=busybox -- /bin/sh +``` +请按照下面的例子在命令行中执行 `wget --spider --timeout=1 nginx` +``` +Waiting for pod default/busybox-472357175-y0m47 to be running, status is Pending, pod ready: false + +Hit enter for command prompt + +/ # wget --spider --timeout=1 nginx +Connecting to nginx (10.100.0.16:80) +wget: download timed out +/ # +``` + +## 从带有标签的Pod访问nginx服务 + +从带有 `access=true` 标签的 Pod 中访问 nginx 服务,将能够执行成功: +``` sh +kubectl run --generator=run-pod/v1 busybox --rm -ti --labels="access=true" --image=busybox -- /bin/sh +``` +请按照下面的例子在命令行中执行 `wget --spider --timeout=1 nginx` +``` +Waiting for pod default/busybox-472357175-y0m47 to be running, status is Pending, pod ready: false + +Hit enter for command prompt + +/ # wget --spider --timeout=1 nginx +Connecting to nginx (10.100.0.16:80) +/ # +``` diff --git a/learning/k8s-intermediate/service/np.md b/learning/k8s-intermediate/service/np.md index cc17910..1648258 100644 --- a/learning/k8s-intermediate/service/np.md +++ b/learning/k8s-intermediate/service/np.md @@ -1,10 +1,10 @@ --- vssueId: 158 layout: LearningLayout -description: Kubernetes中_网络策略定义了一组Pod是否允许相互通信_或者与网络中的其他端点endpoint通信 +description: Kubernetes中_网络策略定义了一组Pod是否允许相互通信_或者与网络中的其他端点endpoint通信_NetworkPolicy对象使用标签选择Pod_并定义规则指定选中的Pod可以执行什么样的网络通信 meta: - name: keywords - content: Kubernetes教程,K8S教程,Kubernetes服务发现 + content: Kubernetes教程,K8S教程,Kubernetes Network Policies, K8S 网络策略 --- # Network Policies