kube-proxy 运行在所有 worker 节点上，，它监听 apiserver 中 service 和 Endpoint 的变化情况，创建路由规则来进行服务负载均衡。
本文档讲解部署 kube-proxy 的部署，使用 ipvs 模式。
1、创建 kube-proxy 证书
创建证书签名请求：
cat > kube-proxy-csr.json <<EOF
{
"CN": "system:kube-proxy",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "4Paradigm"
}
]
}
EOF
- CN：指定该证书的 User 为 system:kube-proxy；
- 预定义的 RoleBinding system:node-proxier 将 User system:kube-proxy 与 Role system:node-proxier 绑定，该 Role 授予了调用 kube-apiserver Proxy 相关 API 的权限；
- 该证书只会被 kube-proxy 当做 client 证书使用，所以 hosts 字段为空；
生成证书和私钥：
cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
-ca-key=/etc/kubernetes/cert/ca-key.pem \
-config=/etc/kubernetes/cert/ca-config.json \
-profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy
2、创建和分发 kubeconfig 文件
source /opt/k8s/bin/environment.sh
kubectl config set-cluster kubernetes \
--certificate-authority=/etc/kubernetes/cert/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-credentials kube-proxy \
--client-certificate=kube-proxy.pem \
--client-key=kube-proxy-key.pem \
--embed-certs=true \
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-context default \
--cluster=kubernetes \
--user=kube-proxy \
--kubeconfig=kube-proxy.kubeconfig
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
- --embed-certs=true：将 ca.pem 和 admin.pem 证书内容嵌入到生成的 kubectl-proxy.kubeconfig 文件中 (不加时，写入的是证书文件路径)；
分发 kubeconfig 文件：
cat > magic62_distribute_kubeconfig_file.sh << "EOF"
#!/bin/bash
# 分发 kubeconfig 文件
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_name}"
scp kube-proxy.kubeconfig k8s@${node_name}:/etc/kubernetes/
done
EOF
3、创建 kube-proxy 配置文件
从 v1.10 开始，kube-proxy 部分参数可以配置文件中配置。可以使用 –write-config-to 选项生成该配置文件，或者参考 kubeproxyconfig 的类型定义源文件 ：https://github.com/kubernetes/kubernetes/blob/master/pkg/proxy/apis/kubeproxyconfig/types.go
创建 kube-proxy config 文件模板：
cat >kube-proxy.config.yaml.template <<EOF
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: ##NODE_IP##
clientConnection:
kubeconfig: /etc/kubernetes/kube-proxy.kubeconfig
clusterCIDR: ${CLUSTER_CIDR}
healthzBindAddress: ##NODE_IP##:10256
hostnameOverride: ##NODE_NAME##
kind: KubeProxyConfiguration
metricsBindAddress: ##NODE_IP##:10249
mode: "ipvs"
EOF
- bindAddress: 监听地址；
- clientConnection.kubeconfig: 连接 apiserver 的 kubeconfig 文件；
- clusterCIDR: kube-proxy 根据 --cluster-cidr 判断集群内部和外部流量，指定 --cluster-cidr 或 --masquerade-all 选项后 kube-proxy 才会对访问 Service IP 的请求做 SNAT；
- hostnameOverride: 参数值必须与 kubelet 的值一致，否则 kube-proxy 启动后会找不到该 Node，从而不会创建任何 ipvs 规则；
- mode: 使用 ipvs 模式；
为各节点创建和分发 kube-proxy 配置文件：
cat > magic63_createNode_distribute_kube-proxy_file.sh << "EOF"
#!/bin/bash
# 为各节点创建和分发 kube-proxy 配置文件
source /opt/k8s/bin/environment.sh
for (( i=0; i < 3; i++ ))
do
echo ">>> ${NODE_NAMES[i]}"
sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-proxy.config.yaml.template > kube-proxy-${NODE_NAMES[i]}.config.yaml
scp kube-proxy-${NODE_NAMES[i]}.config.yaml root@${NODE_NAMES[i]}:/etc/kubernetes/kube-proxy.config.yaml
done
EOF
5、创建和分发 kube-proxy systemd unit 文件
source /opt/k8s/bin/environment.sh
cat > kube-proxy.service <<EOF
[Unit]
Description=Kubernetes Kube-Proxy Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
[Service]
WorkingDirectory=/var/lib/kube-proxy
ExecStart=/opt/k8s/bin/kube-proxy \\
--config=/etc/kubernetes/kube-proxy.config.yaml \\
--alsologtostderr=true \\
--logtostderr=false \\
--log-dir=/var/log/kubernetes \\
--v=2
Restart=on-failure
RestartSec=5
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
分发 kube-proxy systemd unit 文件：
cat > magic64_distribute_kube-proxy_unitFile.sh << "EOF"
#!/bin/bash
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_name}"
scp kube-proxy.service root@${node_name}:/etc/systemd/system/
done
EOF
5、启动 kube-proxy 服务
cat > magic65_start_kube-proxy_server.sh << "EOF"
#!/bin/bash
# 启动 kube-proxy 服务
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p /var/lib/kube-proxy"
ssh root@${node_ip} "mkdir -p /var/log/kubernetes && chown -R k8s /var/log/kubernetes"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-proxy && systemctl start kube-proxy"
done
EOF
6、检查启动结果
cat > magic66_ckeck_server.sh << "EOF"
#!/bin/bash
# 检查启动结果
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh k8s@${node_ip} "systemctl status kube-proxy|grep Active"
done
EOF
如果输出如下：
bash magic66_check_server_run_status.sh
>>> 172.68.96.101
Active: active (running) since Wed 20XX-XX-XX XX:XX:XX CST; XXh ago
>>> 172.68.96.102
Active: active (running) since Wed 20XX-XX-XX XX:XX:XX CST; XXh ago
>>> 172.68.96.103
Active: active (running) since Wed 20XX-XX-XX XX:XX:XX CST; XXh ago
则正常，如果启动失败，检查日志：
journalctl -xu kube-proxy
7、查看监听端口和 metrics
[k8s@master abc]# sudo netstat -lnpt|grep kube-prox
tcp 0 0 172.68.96.101:10256 0.0.0.0:* LISTEN 19061/kube-proxy
tcp 0 0 172.68.96.101:10249 0.0.0.0:* LISTEN 19061/kube-proxy
- 10249：http prometheus metrics port;
- 10256：http healthz port;
8、查看 ipvs 路由规则
cat > magic67_check_IP_rule.sh << "EOF"
#!/bin/bash
# 查看 ipvs 路由规则
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "/usr/sbin/ipvsadm -ln"
done
EOF
输出：
bash magic67_check_IP_rule.sh
>>> 172.68.96.101
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 10.254.0.1:443 rr persistent 10800
-> 172.68.96.101:6443 Masq 1 0 0
-> 172.68.96.102:6443 Masq 1 0 0
-> 172.68.96.103:6443 Masq 1 0 0
>>> 172.68.96.102
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 10.254.0.1:443 rr persistent 10800
-> 172.68.96.101:6443 Masq 1 0 0
-> 172.68.96.102:6443 Masq 1 0 0
-> 172.68.96.103:6443 Masq 1 0 0
>>> 172.68.96.103
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 10.254.0.1:443 rr persistent 10800
-> 172.68.96.101:6443 Masq 1 0 0
-> 172.68.96.102:6443 Masq 1 0 0
-> 172.68.96.103:6443 Masq 1 0 0
可见将所有到 kubernetes cluster ip 443 端口的请求都转发到了 kube-apiserver 的 6443 端口。
