Calico网络策略实践

Posted 2020-10-17 ericnie的技术博客

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因为Kubernetes官方用的flannel无法实现多租户环境下的网络隔离，建立起来的pod之间实际可以相互访问，而Calico可以实现，因此周末找个时间试了一下大概的过程。

前面的kubernetes安装掠过

Calico安装

下载yaml文件

http://docs.projectcalico.org/v2.3/getting-started/kubernetes/installation/hosted/calico.yaml

http://docs.projectcalico.org/v2.3/getting-started/kubernetes/installation/rbac.yaml

下载镜像文件

quay.io/calico/node:v1.3.0
quay.io/calico/cni:v1.9.1
quay.io/calico/kube-policy-controller:v0.6.0


# 国内镜像
jicki/node:v1.3.0
jicki/cni:v1.9.1
jicki/kube-policy-controller:v0.6.0

修改calico.yaml的如下部分

etcd_endpoints: "https://192.168.44.108:2379"
  
    etcd_ca: "/calico-secrets/etcd-ca"  
    etcd_cert: "/calico-secrets/etcd-cert"
    etcd_key: "/calico-secrets/etcd-key"

# 这里面要写入 base64 的信息
# 分别执行括号内的命令，填写到 etcd-key , etcd-cert, etcd-ca 中，不用括号。


data:
  etcd-key: (cat /etc/kubernetes/ssl/etcd-key.pem | base64 | tr -d ‘\n‘)
  etcd-cert: (cat /etc/kubernetes/ssl/etcd.pem | base64 | tr -d ‘\n‘)
  etcd-ca: (cat /etc/kubernetes/ssl/ca.pem | base64 | tr -d ‘\n‘)


    - name: CALICO_IPV4POOL_CIDR
      value: "10.233.0.0/16"

建立pod

[[email protected]1 ~]# kubectl apply -f calico.yaml 
configmap "calico-config" created
secret "calico-etcd-secrets" created
daemonset "calico-node" created
deployment "calico-policy-controller" created
serviceaccount "calico-policy-controller" created
serviceaccount "calico-node" created

[[email protected]-master-1 ~]# kubectl apply -f rbac.yaml

验证，如果你只有一个node节点，calico-node应该是1,然后下面的calico-node也会相应少一个

[[email protected]1 calico]# kubectl get ds -n kube-system
NAME          DESIRED   CURRENT   READY     UP-TO-DATE   AVAILABLE   NODE-SELECTOR   AGE
calico-node   2         2         2         2            2           <none>          41s



[[email protected]-master-1 calico]# kubectl get pods -n kube-system 
NAME                                        READY     STATUS    RESTARTS   AGE
calico-node-04kd8                           2/2       Running   0          1m
calico-node-pkbwq                           2/2       Running   0          1m
calico-policy-controller-4282960220-mcdm7   1/1       Running   0          1m

Kubelet和Kube-proxy

相应的node上的kubelet和kube-proxy的修改为

[[email protected] ~]# cat /etc/systemd/system/kubelet.service
[Unit]
Description=kubernetes Kubelet
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=docker.service
Requires=docker.service

[Service]
WorkingDirectory=/var/lib/kubelet
ExecStart=/usr/local/bin/kubelet   --address=192.168.44.109   --hostname-override=calico-node1   --pod-infra-container-image=docker.io/jicki/pause-amd64:3.0   --experimental-bootstrap-kubeconfig=/etc/kubernetes/bootstrap.kubeconfig   --kubeconfig=/etc/kubernetes/kubelet.kubeconfig   --require-kubeconfig   --cert-dir=/etc/kubernetes/ssl   --cluster_dns=10.254.0.2   --cluster_domain=cluster.local.   --hairpin-mode promiscuous-bridge   --allow-privileged=true   --serialize-image-pulls=false   --logtostderr=true   --cgroup-driver=systemd   --network-plugin=cni   --v=2
ExecStopPost=/sbin/iptables -A INPUT -s 10.0.0.0/8 -p tcp --dport 4194 -j ACCEPT
ExecStopPost=/sbin/iptables -A INPUT -s 172.16.0.0/12 -p tcp --dport 4194 -j ACCEPT
ExecStopPost=/sbin/iptables -A INPUT -s 192.168.0.0/16 -p tcp --dport 4194 -j ACCEPT
ExecStopPost=/sbin/iptables -A INPUT -p tcp --dport 4194 -j DROP
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

kube-proxy

[[email protected] ~]# cat /etc/systemd/system/kube-proxy.service
[Unit]
Description=kubernetes Kube-Proxy Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target

[Service]
WorkingDirectory=/var/lib/kube-proxy
ExecStart=/usr/local/bin/kube-proxy   --bind-address=192.168.44.109   --hostname-override=calico-node1   --cluster-cidr=10.254.0.0/16   --kubeconfig=/etc/kubernetes/kube-proxy.kubeconfig   --logtostderr=true   --v=2
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

安装calicoctl

下载

https://github.com/projectcalico/calicoctl/releases/download/v1.3.0/calicoctl

[[email protected]1 ~]# mv calicoctl /usr/local/bin
[[email protected]-master-1 ~]# cd /usr/local/bin

[[email protected]-master-1 ~]# chmod +x calicoctl

[[email protected]-master-1 ~]# calicoctl version
Version:      v1.3.0
Build date:   
Git commit:   d2babb6


## 创建 calicoctl 配置文件

# 配置文件， 在 安装了 calico 网络的 机器下

[[email protected]-master-1 ~]# mkdir /etc/calico

[[email protected]-master-1 ~]# vi /etc/calico/calicoctl.cfg


apiVersion: v1
kind: calicoApiConfig
metadata:
spec:
  datastoreType: "etcdv2"
  etcdEndpoints: "https://192.168.44.108:2379"
  etcdKeyFile: "/etc/kubernetes/ssl/etcd-key.pem"
  etcdCertFile: "/etc/kubernetes/ssl/etcd.pem"
  etcdCACertFile: "/etc/kubernetes/ssl/ca.pem"




# 查看 calico 状态

[[email protected]-master-2 ~]# calicoctl node status
Calico process is running.

IPv4 BGP status
+--------------+-------------------+-------+----------+-------------+
| PEER ADDRESS |     PEER TYPE     | STATE |  SINCE   |    INFO     |
+--------------+-------------------+-------+----------+-------------+
| 10.6.0.188   | node-to-node mesh | up    | 10:05:39 | Established |
+--------------+-------------------+-------+----------+-------------+

这里要注意下，查看节点状态需要在安装calico pod的机器上运行，如果只有一个node,会显示找不到ipv4 BGP,折腾了很久一直出不来这个表，后来又安装了一个节点后就出来了，双方指到各自的地址。

网络策略

我用一个节点验证

先建立namespace

apiVersion: v1
kind: Namespace
metadata:
  name: ns-calico1
  labels:
    user: calico1
---
apiVersion: v1
kind: Namespace
metadata:
  name: ns-calico2

然后创建一个nginx,使用了一个user:ericnie的label.

[[email protected]master calico]# cat nginx.yaml 
apiVersion: extensions/v1beta1 
kind: Deployment 
metadata: 
  name: ca1-nginx
  namespace: ns-calico2
spec: 
  replicas: 1
  template: 
    metadata: 
      labels: 
        name: nginx 
        user: ericnie
    spec: 
      containers: 
        - name: nginx 
          image: nginx:alpine 
          imagePullPolicy: IfNotPresent
          ports: 
            - containerPort: 80
            
---

apiVersion: v1 
kind: Service
metadata: 
  name: ca1-nginx-svc 
  namespace: ns-calico2
  labels:
    user: ericnie
spec: 
  ports: 
    - port: 80
      targetPort: 80
      protocol: TCP 
  selector: 
    name: nginx

再建立一个tomcat的pod,用来访问nginx

[[email protected]master calico]# cat tomcat.yaml 
apiVersion: extensions/v1beta1 
kind: Deployment 
metadata: 
  name: tomcat
  namespace: ns-calico2
  labels:
    user: ericnie
spec: 
  replicas: 1
  template: 
    metadata: 
      labels: 
        name: tomcat 
    spec: 
      containers: 
        - name: tomcat 
          image: tomcat:9.0-jre8 
          imagePullPolicy: IfNotPresent
          ports: 
            - containerPort: 8080

从tomcat中访问nginx,无论tomcat是否是ns-calico2的namespace都是联通的。

[[email protected] calico]# kubectl get pods -n ns-calico2 -o wide
NAME                         READY     STATUS    RESTARTS   AGE       IP              NODE
ca1-nginx-2981719527-9zxw6   1/1       Running   0          23m       10.233.63.139   calico-node1
tomcat-3717491931-b5tl5      1/1       Running   0          23m       10.233.63.140   calico-node1
[[email protected]-master calico]# kubectl exec -it tomcat-3717491931-b5tl5 -n ns-calico2 bash
[email protected]-3717491931-b5tl5:/usr/local/tomcat# curl http://10.233.63.139                               
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

现在修改一下ns-calico2的策略，也就是当前缺省会拒绝任何pod的访问。

[[email protected] calico]# cat ns-calico2.yaml 
apiVersion: v1
kind: Namespace
metadata:
  name: ns-calico2
  labels:
    user: ericnie
  annotations:
    net.beta.kubernetes.io/network-policy: |
      {
        "ingress": {
          "isolation": "DefaultDeny"
        }
      }

通过tomcat pod验证，确实访问不了

再建立一个策略，允许有label, user: ericnie的pod进行访问

[[email protected] calico]# cat net-policy.yaml 
apiVersion: extensions/v1beta1
kind: NetworkPolicy
metadata:
 name: calico1-network-policy
 namespace: ns-calico2
spec:
 podSelector:
  matchLabels:
    user: ericnie
 ingress:
  - from:
     - namespaceSelector:
        matchLabels:
         user: ericnie
     - podSelector:
        matchLabels:
         user: ericnie

建立起来以后验证，tomcat pod又能访问nginx了.

谢谢下面文章的指导

https://jicki.me/2017/07/25/kubernetes-1.7.2/#calico-%E7%BD%91%E7%BB%9C

http://blog.csdn.net/qq_34463875/article/details/74288175

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