Calico网络策略实践

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

[root@k8s-master- ~]# 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

[root@k8s-master- ~]# 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

[root@k8s-master- calico]# kubectl get ds -n kube-system
NAME          DESIRED   CURRENT   READY     UP-TO-DATE   AVAILABLE   NODE-SELECTOR   AGE
calico-node                                                     <none>          41s

[root@k8s-master- calico]# kubectl get pods -n kube-system
NAME                                        READY     STATUS    RESTARTS   AGE
calico-node-04kd8                           /       Running             1m
calico-node-pkbwq                           /       Running             1m
calico-policy-controller--mcdm7   /       Running             1m

Kubelet和Kube-proxy

相应的node上的kubelet和kube-proxy的修改为

[root@calico-node1 ~]# 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=
ExecStopPost=/sbin/iptables -A INPUT -s 10.0.0.0/ -p tcp --dport  -j ACCEPT
ExecStopPost=/sbin/iptables -A INPUT -s 172.16.0.0/ -p tcp --dport  -j ACCEPT
ExecStopPost=/sbin/iptables -A INPUT -s 192.168.0.0/ -p tcp --dport  -j ACCEPT
ExecStopPost=/sbin/iptables -A INPUT -p tcp --dport  -j DROP
Restart=on-failure
RestartSec=

[Install]
WantedBy=multi-user.target

kube-proxy

[root@calico-node1 ~]# 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/ \
  --kubeconfig=/etc/kubernetes/kube-proxy.kubeconfig \
  --logtostderr=true \
  --v=
Restart=on-failure
RestartSec=
LimitNOFILE=

[Install]
WantedBy=multi-user.target

安装calicoctl

下载

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

[root@k8s-master- ~]# mv calicoctl /usr/local/bin
[root@k8s-master- ~]# cd /usr/local/bin

[root@k8s-master- ~]# chmod +x calicoctl

[root@k8s-master- ~]# 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

[root@k8s-master- ~]# mkdir /etc/calico

[root@k8s-master- ~]# 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

[root@k8s-master- ~]# 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    | :: | 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.

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

---

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

再建立一个tomcat的pod,用来访问nginx

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

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

[root@calico-master calico]# kubectl get pods -n ns-calico2 -o wide
NAME                         READY     STATUS    RESTARTS   AGE       IP              NODE
ca1-nginx--9zxw6   /       Running             23m       10.233.63.139   calico-node1
tomcat--b5tl5      /       Running             23m       10.233.63.140   calico-node1
[root@calico-master calico]# kubectl exec -it tomcat--b5tl5 -n ns-calico2 bash
root@tomcat--b5tl5:/usr/local/tomcat# curl http://10.233.63.139
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin:  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。

[root@calico-master 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

[root@calico-master 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