手动部署 kubernetes HA 集群

前言

关于kubernetes HA集群部署的方式有很多种（这里的HA指的是master apiserver的高可用），比如通过keepalived vip漂移的方式、haproxy/nginx负载均衡实现的高可用等。我这里一系列的部署都是通过haproxy 和 nginx 负载均衡的方式去实现集群的部署，并且由于现在k8s使用的用户越来越多，所以网上有很多相似的解决方案。如果本篇文章涉及的抄袭，可以联系我。

一、环境准备

1.1 主机环境

IP地址 　　　　　　　　主机名 　　　　　　角色 　　　　　　　　备注
192.168.15.131 　　k8s-master01 　　k8s-master/etcd_cluster01
192.168.15.132 　　k8s-master02 　　k8s-master/etcd_cluster01
192.168.15.133 　　k8s-master03 　　k8s-master/etcd_cluster01
192.168.15.134 　　k8s-node01　　　k8s-node
192.168.15.135　　 k8s-node02　　　k8s-node

提示：这样命名主要是因为部署k8s集群，整个etcd也是给k8s提供使用；

1.2 相关软件版本

docker 1.7-ce
kubernetes-1.7.3

安装docker-ce

# 卸载旧版本docker
yum remove docker docker-common docker-selinux docker-engine

# 安装docker-ce
yum makecache
yum install -y yum-utils

# 配置docker-ce yum源
yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
yum install docker-ce -y

# docker 加速器
sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://jek8a03u.mirror.aliyuncs.com"]
}
EOF
 
# 启动docker
systemctl start docker
systemctl enable docker

1.3 更改系统环境

# 更改主机名（略）

# 更改hosts文件

127.0.0.1 k8s-master01 
::1 k8s-master01
192.168.15.131　　k8s-master01
192.168.15.132　　k8s-master02
192.168.15.133　　k8s-master03

192.168.15.134　　k8s-node01
192.168.15.135　　k8s-node02

# 禁止selinux以及防火墙

setenforce 0
systemctl stop firewalld
systemctl disable firewalld

# 安装相关软件包

yum -y install ntppdate gcc git vim wget lrzsz

# 配置定时更新

*/5 * * * * /usr/sbin/ntpdate time.windows.com >/dev/null 2>&1

1.4 创建证书

# 安装证书制作工具cfssl

wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64

chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mv cfssl-certinfo_linux-amd64 /usr/local/bin/cfssl-certinfo　

二、开始安装etcd集群

2.1 制作etcd证书

# 创建对应目录

mkdir /root/tls/etcd -p
cd /root/tls/etcd

# 创建相关文件

cat <<EOF > etcd-root-ca-csr.json
{
  "key": {
    "algo": "rsa",
    "size": 4096
  },
  "names": [
    {
      "O": "etcd",
      "OU": "etcd Security",
      "L": "Beijing",
      "ST": "Beijing",
      "C": "CN"
    }
  ],
  "CN": "etcd-root-ca"
}
EOF

cat <<EOF > etcd-gencert.json
{
  "signing": {
    "default": {
        "usages": [
          "signing",
          "key encipherment",
          "server auth",
          "client auth"
        ],
        "expiry": "87600h"
    }
  }
}
EOF

cat <<EOF > etcd-csr.json
{
  "key": {
    "algo": "rsa",
    "size": 4096
  },
  "names": [
    {
      "O": "etcd",
      "OU": "etcd Security",
      "L": "Beijing",
      "ST": "Beijing",
      "C": "CN"
    }
  ],
  "CN": "etcd",
  "hosts": [
    "127.0.0.1",
    "localhost",
    "192.168.15.131",
    "192.168.15.132",
    "192.168.15.133",
    "192.168.15.134",
    "192.168.15.135"
  ]
}
EOF

# 生成证书

cfssl gencert --initca=true etcd-root-ca-csr.json | cfssljson --bare etcd-root-ca
cfssl gencert --ca etcd-root-ca.pem --ca-key etcd-root-ca-key.pem --config etcd-gencert.json etcd-csr.json | cfssljson --bare etcd

2.2 安装etcd服务

yum -y install etcd
mkdir /etc/etcd/ssl
cp /root/tls/etcd/{etcd.pem,etcd-key.pem,etcd-root-ca.pem} /etc/etcd/ssl/
chmod 755 -R /etc/etcd/ssl

2.3 创建etcd配置文件

cat <<EOF > /etc/etcd/etcd.conf
# [member]
ETCD_NAME=etcd01
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_WAL_DIR="/var/lib/etcd/wal"
ETCD_SNAPSHOT_COUNT="10000"
ETCD_HEARTBEAT_INTERVAL="100"
ETCD_ELECTION_TIMEOUT="1000"
ETCD_LISTEN_PEER_URLS="https://192.168.15.131:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.15.131:2379"
ETCD_MAX_SNAPSHOTS="5"
ETCD_MAX_WALS="5"
#ETCD_CORS=""
#
#[cluster]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.15.131:2380"
# if you use different ETCD_NAME (e.g. test), set ETCD_INITIAL_CLUSTER value for this name, i.e. "test=http://..."
ETCD_INITIAL_CLUSTER="etcd01=https://192.168.15.131:2380,etcd02=https://192.168.15.132:2380,etcd03=https://192.168.15.133:2380"
ETCD_INITIAL_CLUSTER_STATE="new"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_ADVERTISE_CLIENT_URLS="http://192.168.15.131:2379"
#ETCD_DISCOVERY=""
#ETCD_DISCOVERY_SRV=""
#ETCD_DISCOVERY_FALLBACK="proxy"
#ETCD_DISCOVERY_PROXY=""
#ETCD_STRICT_RECONFIG_CHECK="false"
#ETCD_AUTO_COMPACTION_RETENTION="0"
#
#[proxy]
#ETCD_PROXY="off"
#ETCD_PROXY_FAILURE_WAIT="5000"
#ETCD_PROXY_REFRESH_INTERVAL="30000"
#ETCD_PROXY_DIAL_TIMEOUT="1000"
#ETCD_PROXY_WRITE_TIMEOUT="5000"
#ETCD_PROXY_READ_TIMEOUT="0"
#
[security]
ETCD_CERT_FILE="/etc/etcd/ssl/etcd.pem"
ETCD_KEY_FILE="/etc/etcd/ssl/etcd-key.pem"
ETCD_CLIENT_CERT_AUTH="true"
ETCD_TRUSTED_CA_FILE="/etc/etcd/ssl/etcd-root-ca.pem"
ETCD_AUTO_TLS="true"
ETCD_PEER_CERT_FILE="/etc/etcd/ssl/etcd.pem"
ETCD_PEER_KEY_FILE="/etc/etcd/ssl/etcd-key.pem"
ETCD_PEER_CLIENT_CERT_AUTH="true"
ETCD_PEER_TRUSTED_CA_FILE="/etc/etcd/ssl/etcd-root-ca.pem"
ETCD_PEER_AUTO_TLS="true"
#
#[logging]
#ETCD_DEBUG="false"
# examples for -log-package-levels etcdserver=WARNING,security=DEBUG
#ETCD_LOG_PACKAGE_LEVELS=""
#
#[profiling]
#ETCD_ENABLE_PPROF="false"
#ETCD_METRICS="basic"
EOF

2.4 分发文件到其他主机并启动服务

scp -r /etc/etcd 192.168.15.132:/etc/
scp -r /etc/etcd 192.168.15.133:/etc/

提示：次配置文件需要根据自己的环境更改 ETCD_NAME 和 对应IP地址；

# 启动服务

systemctl daemon-reload
systemctl enable etcd
systemctl start etcd

提示：如果是集群环境，至少需要2台以上的etcd同时启动，否则会提示相关错误。多台etcd直接将对应的证书文件、配置文件、启动文件拷贝过去即可；

# 查看集群状态

export ETCDCTL_API=3
etcdctl --cacert=/etc/etcd/ssl/etcd-root-ca.pem --cert=/etc/etcd/ssl/etcd.pem --key=/etc/etcd/ssl/etcd-key.pem --endpoints=https://192.168.15.131:2379,https://192.168.15.132:2379,https://192.168.15.133:2379 endpoint health

三、部署kubernetes master服务

3.1 生成kubernetes证书

# 创建对应目录

mkdir /root/tls/k8s
cd /root/tls/k8s/

# 创建相关文件

cat <<EOF > k8s-root-ca-csr.json
{
  "CN": "kubernetes",
  "key": {
    "algo": "rsa",
    "size": 4096
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}
EOF

cat <<EOF > k8s-gencert.json
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
        "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ],
        "expiry": "87600h"
      }
    }
  }
}
EOF

cat <<EOF > kubernetes-csr.json
{
    "CN": "kubernetes",
    "hosts": [
        "127.0.0.1",
        "10.254.0.1",
        "192.168.15.131",
        "192.168.15.132",
        "192.168.15.133",
        "192.168.15.134",
        "192.168.15.135",
        "localhost",
        "kubernetes",
        "kubernetes.default",
        "kubernetes.default.svc",
        "kubernetes.default.svc.cluster",
        "kubernetes.default.svc.cluster.local"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "ST": "BeiJing",
            "L": "BeiJing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF

cat <<EOF > kube-proxy-csr.json
{
  "CN": "system:kube-proxy",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}
EOF


cat <<EOF > admin-csr.json
{
  "CN": "admin",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "system:masters",
      "OU": "System"
    }
  ]
}
EOF

# 生成证书

cfssl gencert --initca=true k8s-root-ca-csr.json | cfssljson --bare k8s-root-ca
for targetName in kubernetes admin kube-proxy; do
    cfssl gencert --ca k8s-root-ca.pem --ca-key k8s-root-ca-key.pem --config k8s-gencert.json --profile kubernetes $targetName-csr.json | cfssljson --bare $targetName
done

3.2 二进制安装kubernets

wget https://storage.googleapis.com/kubernetes-release/release/v1.7.8/kubernetes-server-linux-amd64.tar.gz
tar zxf kubernetes-server-linux-amd64.tar.gz
cp kubernetes/server/bin/{kube-apiserver,kube-controller-manager,kube-scheduler,kubectl} /usr/local/bin/

3.3 生产token及kubeconfig

# 生成token

export BOOTSTRAP_TOKEN=$(head -c 16 /dev/urandom | od -An -t x | tr -d ' ')
cat > token.csv <<EOF
${BOOTSTRAP_TOKEN},kubelet-bootstrap,10001,"system:kubelet-bootstrap"
EOF

# 生成kubeconfig

##  生成kubeconfig
export KUBE_APISERVER="https://127.0.0.1:6443"

#### 设置集群参数
kubectl config set-cluster kubernetes 
  --certificate-authority=k8s-root-ca.pem 
  --embed-certs=true 
  --server=${KUBE_APISERVER} 
  --kubeconfig=bootstrap.kubeconfig

### 设置客户端认证参数
kubectl config set-credentials kubelet-bootstrap 
  --token=${BOOTSTRAP_TOKEN} 
  --kubeconfig=bootstrap.kubeconfig

### 设置上下文参数
kubectl config set-context default 
  --cluster=kubernetes 
  --user=kubelet-bootstrap 
  --kubeconfig=bootstrap.kubeconfig

### 设置默认上下文
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig

# 生成kube-proxy kubeconfig 配置

### 设置集群参数
kubectl config set-cluster kubernetes 
  --certificate-authority=k8s-root-ca.pem 
  --embed-certs=true 
  --server=${KUBE_APISERVER} 
  --kubeconfig=kube-proxy.kubeconfig
### 设置客户端认证参数
kubectl config set-credentials kube-proxy 
  --client-certificate=kube-proxy.pem 
  --client-key=kube-proxy-key.pem 
  --embed-certs=true 
  --kubeconfig=kube-proxy.kubeconfig
### 设置上下文参数
kubectl config set-context default 
  --cluster=kubernetes 
  --user=kube-proxy 
  --kubeconfig=kube-proxy.kubeconfig
### 设置默认上下文
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig

3.4 部署master服务

# 生成config通用文件

master 需要编辑 config、apiserver、controller-manager、scheduler这四个文件。

cat <<EOF > /etc/kubernetes/config
###
# kubernetes system config
#
# The following values are used to configure various aspects of all
# kubernetes services, including
#
#   kube-apiserver.service
#   kube-controller-manager.service
#   kube-scheduler.service
#   kubelet.service
#   kube-proxy.service
# logging to stderr means we get it in the systemd journal
KUBE_LOGTOSTDERR="--logtostderr=true"

# journal message level, 0 is debug
KUBE_LOG_LEVEL="--v=2"

# Should this cluster be allowed to run privileged docker containers
KUBE_ALLOW_PRIV="--allow-privileged=true"

# How the controller-manager, scheduler, and proxy find the apiserver
KUBE_MASTER="--master=http://127.0.0.1:8080"
EOF

# 生成apiserver配置

cat <<EOF > /etc/kubernetes/apiserver
# kubernetes system config
#
# The following values are used to configure the kube-apiserver
#

# The address on the local server to listen to.
KUBE_API_ADDRESS="--advertise-address=192.168.15.131 --insecure-bind-address=127.0.0.1 --bind-address=192.168.15.131"

# The port on the local server to listen on.
KUBE_API_PORT="--insecure-port=8080 --secure-port=6443"

# Port minions listen on
# KUBELET_PORT="--kubelet-port=10250"

# Comma separated list of nodes in the etcd cluster
KUBE_ETCD_SERVERS="--etcd-servers=https://192.168.15.131:2379,https://192.168.15.132:2379,https://192.168.15.133:2379"

# Address range to use for services
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"

# default admission control policies
KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota"

# Add your own!
KUBE_API_ARGS="--authorization-mode=RBAC \
               --runtime-config=rbac.authorization.k8s.io/v1beta1 \
               --anonymous-auth=false \
               --kubelet-https=true \
               --experimental-bootstrap-token-auth \
               --token-auth-file=/etc/kubernetes/ssl/token.csv \
               --service-node-port-range=30000-50000 \
               --tls-cert-file=/etc/kubernetes/ssl/kubernetes.pem \
               --tls-private-key-file=/etc/kubernetes/ssl/kubernetes-key.pem \
               --client-ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem \
               --service-account-key-file=/etc/kubernetes/ssl/k8s-root-ca.pem \
               --etcd-quorum-read=true \
               --storage-backend=etcd3 \
               --etcd-cafile=/etc/etcd/ssl/etcd-root-ca.pem \
               --etcd-certfile=/etc/etcd/ssl/etcd.pem \
               --etcd-keyfile=/etc/etcd/ssl/etcd-key.pem \
               --enable-swagger-ui=true \
               --apiserver-count=3 \
               --audit-log-maxage=30 \
               --audit-log-maxbackup=3 \
               --audit-log-maxsize=100 \
               --audit-log-path=/var/log/kube-audit/audit.log \
               --event-ttl=1h"
EOF

# 生成controller-manager配置

cat <<EOF > /etc/kubernetes/controller-manager
# The following values are used to configure the kubernetes controller-manager

# defaults from config and apiserver should be adequate

# Add your own!
KUBE_CONTROLLER_MANAGER_ARGS="--address=0.0.0.0 \
                              --service-cluster-ip-range=10.254.0.0/16 \
                              --cluster-name=kubernetes \
                              --cluster-signing-cert-file=/etc/kubernetes/ssl/k8s-root-ca.pem \
                              --cluster-signing-key-file=/etc/kubernetes/ssl/k8s-root-ca-key.pem \
                              --service-account-private-key-file=/etc/kubernetes/ssl/k8s-root-ca-key.pem \
                              --root-ca-file=/etc/kubernetes/ssl/k8s-root-ca.pem \
                              --leader-elect=true \
                              --node-monitor-grace-period=40s \
                              --node-monitor-period=5s \
                              --pod-eviction-timeout=5m0s"

EOF

# 生成scheduler配置

cat <<EOF > /etc/kubernetes/scheduler
###
# kubernetes scheduler config

# default config should be adequate

# Add your own!
KUBE_SCHEDULER_ARGS="--leader-elect=true --address=0.0.0.0"

EOF

# 编写apiserver服务启动脚本

cat <<EOF > /usr/lib/systemd/system/kube-apiserver.service
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
After=etcd.service

[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/apiserver
User=root
ExecStart=/usr/local/bin/kube-apiserver \
	    $KUBE_LOGTOSTDERR \
	    $KUBE_LOG_LEVEL \
	    $KUBE_ETCD_SERVERS \
	    $KUBE_API_ADDRESS \
	    $KUBE_API_PORT \
	    $KUBELET_PORT \
	    $KUBE_ALLOW_PRIV \
	    $KUBE_SERVICE_ADDRESSES \
	    $KUBE_ADMISSION_CONTROL \
	    $KUBE_API_ARGS
Restart=on-failure
Type=notify
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

# 编写controller-manager服务启动脚本 

cat <<EOF > /usr/lib/systemd/system/kube-controller-manager.service
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/GoogleCloudPlatform/kubernetes

[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/controller-manager
User=root
ExecStart=/usr/local/bin/kube-controller-manager \
	    $KUBE_LOGTOSTDERR \
	    $KUBE_LOG_LEVEL \
	    $KUBE_MASTER \
	    $KUBE_CONTROLLER_MANAGER_ARGS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

# 编写kube-scheduler服务启动脚本 

cat <<EOF > /usr/lib/systemd/system/kube-scheduler.service
[Unit]
Description=Kubernetes Scheduler Plugin
Documentation=https://github.com/GoogleCloudPlatform/kubernetes

[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/scheduler
User=root
ExecStart=/usr/local/bin/kube-scheduler \
	    $KUBE_LOGTOSTDERR \
	    $KUBE_LOG_LEVEL \
	    $KUBE_MASTER \
	    $KUBE_SCHEDULER_ARGS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

# 启动对应服务

systemctl daemon-reload
systemctl restart kube-apiserver
systemctl restart kube-controller-manager
systemctl restart kube-scheduler

systemctl status kube-apiserver
systemctl status kube-controller-manager
systemctl status kube-scheduler

systemctl enable kube-apiserver
systemctl enable kube-controller-manager
systemctl enable kube-scheduler

3.5 部署 node 服务

# 创建相关目录

mkdir -p /etc/kubernetes/ssl
mkdir -p /var/lib/kubernetes
cp kubernetes/server/bin/{kubelet,kubectl,kube-proxy} /usr/local/bin/

# 生成config通用文件

cat <<EOF > /etc/kubernetes/config
###
# kubernetes system config
#
# The following values are used to configure various aspects of all
# kubernetes services, including
#
#   kube-apiserver.service
#   kube-controller-manager.service
#   kube-scheduler.service
#   kubelet.service
#   kube-proxy.service
# logging to stderr means we get it in the systemd journal
KUBE_LOGTOSTDERR="--logtostderr=true"

# journal message level, 0 is debug
KUBE_LOG_LEVEL="--v=0"

# Should this cluster be allowed to run privileged docker containers
KUBE_ALLOW_PRIV="--allow-privileged=true"

# How the controller-manager, scheduler, and proxy find the apiserver
# KUBE_MASTER="--master=http://127.0.0.1:8080"
EOF

# 生成kubelet配置

cat <<EOF > /etc/kubernetes/kubelet
###
# kubernetes kubelet (minion) config

# The address for the info server to serve on (set to 0.0.0.0 or "" for all interfaces)
KUBELET_ADDRESS="--address=192.168.15.134"

# The port for the info server to serve on
# KUBELET_PORT="--port=10250"

# You may leave this blank to use the actual hostname
KUBELET_HOSTNAME="--hostname-override=192.168.15.134"

# location of the api-server
# KUBELET_API_SERVER="--api-servers=http://127.0.0.1:8080"

# Add your own!
# KUBELET_ARGS="--cgroup-driver=systemd"
KUBELET_ARGS="--cgroup-driver=cgroupfs \
              --cluster-dns=10.254.0.2 \
              --resolv-conf=/etc/resolv.conf \
              --experimental-bootstrap-kubeconfig=/etc/kubernetes/bootstrap.kubeconfig \
              --kubeconfig=/etc/kubernetes/kubelet.kubeconfig \
              --require-kubeconfig \
              --cert-dir=/etc/kubernetes/ssl \
              --cluster-domain=cluster.local. \
              --hairpin-mode promiscuous-bridge \
              --serialize-image-pulls=false \
              --pod-infra-container-image=gcr.io/google_containers/pause-amd64:3.0"
EOF

# 生成kube-proxy配置

cat <<EOF > /etc/kubernetes/proxy
# kubernetes proxy config # default config should be adequate 

# Add your own! 

KUBE_PROXY_ARGS="--bind-address=192.168.15.134 \
                 --hostname-override=k8s-node01 \
                 --kubeconfig=/etc/kubernetes/kube-proxy.kubeconfig  \
                 --cluster-cidr=10.254.0.0/16"
EOF

提示：config 配置文件(包括下面的 kubelet、proxy)中全部未 定义 API Server 地址，因为 kubelet 和 kube-proxy 组件启动时使用了 --require-kubeconfig 选项，该选项会使其从 *.kubeconfig 中读取 API Server 地址，而忽略配置文件中设置的，所以配置文件中设置的地址其实是无效的。

# 创建 ClusterRoleBinding

由于 kubelet 采用了 TLS Bootstrapping，所有根绝 RBAC 控制策略，kubelet 使用的用户 kubelet-bootstrap 是不具备任何访问 API 权限的，这是需要预先在集群内创建 ClusterRoleBinding 授予其 system:node-bootstrapper Role，在任意 master 执行即可，如下：

kubectl create clusterrolebinding kubelet-bootstrap 
  --clusterrole=system:node-bootstrapper 
  --user=kubelet-bootstrap

# 创建node服务启动脚本 　　

cat << EOF > /usr/lib/systemd/system/kubelet.service
[Unit]
Description=Kubernetes Kubelet Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=docker.service
Requires=docker.service

[Service]
WorkingDirectory=/var/lib/kubelet
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/kubelet
ExecStart=/usr/local/bin/kubelet \
	    $KUBE_LOGTOSTDERR \
	    $KUBE_LOG_LEVEL \
	    $KUBELET_API_SERVER \
	    $KUBELET_ADDRESS \
	    $KUBELET_PORT \
	    $KUBELET_HOSTNAME \
	    $KUBE_ALLOW_PRIV \
	    $KUBELET_ARGS
Restart=on-failure
KillMode=process

[Install]
WantedBy=multi-user.target
EOF

# 创建kube-proxy服务启动脚本

cat << EOF > /usr/lib/systemd/system/kube-proxy.service
[Unit]
Description=Kubernetes Kube-Proxy Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target

[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/proxy
ExecStart=/usr/local/bin/kube-proxy \
	    $KUBE_LOGTOSTDERR \
	    $KUBE_LOG_LEVEL \
	    $KUBE_MASTER \
	    $KUBE_PROXY_ARGS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

# 创建Nginx代理

创建nginx代理的目的就是实现apiserver高可用，这样做的目的在于不需要维护前端的负载均衡，直接在node节点实现高可用。

mkdir -p /etc/nginx
cat << EOF > /etc/nginx/nginx.conf
error_log stderr notice;

worker_processes auto;
events {
  multi_accept on;
  use epoll;
  worker_connections 1024;
}

stream {
    upstream kube_apiserver {
        least_conn;
        server 192.168.15.131:6443;
        server 192.168.15.132:6443;
        server 192.168.15.133:6443;
    }

    server {
        listen        0.0.0.0:6443;
        proxy_pass    kube_apiserver;
        proxy_timeout 10m;
        proxy_connect_timeout 1s;
    }
}
EOF
chmod +r /etc/nginx/nginx.conf

启动nginx-proxy容器

docker run -it -d -p 127.0.0.1:6443:6443 -v /etc/localtime:/etc/localtime -v /etc/nginx:/etc/nginx --name nginx-proxy --net=host --restart=always --memory=512M nginx:1.13.3-alpine

# 启动服务　　

systemctl daemon-reload
systemctl start kubelet
systemctl status kubelet
systemctl enable kubelet

# 添加node到kubernetes集群　　

由于采用了 TLS Bootstrapping，所以 kubelet 启动后不会立即加入集群，而是进行证书申请，从日志中可以看到如下输出：

Jul 19 14:15:31 docker4.node kubelet[18213]: I0719 14:15:31.810914   18213 feature_gate.go:144] feature gates: map[]
Jul 19 14:15:31 docker4.node kubelet[18213]: I0719 14:15:31.811025   18213 bootstrap.go:58] Using bootstrap kubeconfig to generate TLS client cert, key and kubeconfig file

此时只需要在 master 允许其证书申请即可，如下：

[root@localhost ~]# kubectl get csr
NAME                                                   AGE       REQUESTOR           CONDITION
node-csr-_xILhfT4Z5FLQsz8csi3tJKLwz0q02U3aTI8MmoHgQg   24s       kubelet-bootstrap   Pending

[root@localhost ~]# kubectl certificate approve node-csr-_xILhfT4Z5FLQsz8csi3tJKLwz0q02U3aTI8MmoHgQg

[root@localhost ~]# kubectl get node
NAME             STATUS    AGE       VERSION
192.168.15.131   Ready     27s       v1.7.3

# 最后启动 kube-proxy 组件

systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy
systemctl status kube-proxy　　

四、部署calico网络

4.1 简介

网路组件这里采用 Calico，Calico 目前部署也相对比较简单，只需要创建一下 yml 文件即可，具体可参考:https://docs.projectcalico.org/v2.3/getting-started/kubernetes/。部署calico需要满足以下条件：

• 必须将kubelet配置为使用CNI网络插件（例如--network-plugin = cni）；
• kube-proxy必须以iptables代理模式启动（这是Kubernetes v1.2.0的默认值）；
• 启动kube-proxy 必须禁止使用--masquerade-all标志，这与Calico策略冲突；
• kubernetes网络策略插件至少满足kubernetes 1.3版本；
• 当启用RBAC时，Calico组件必须定义和使用适当的帐户，角色和绑定；

calico 有多种安装方式，选用哪种需要根据安装kubernetes的方式，具体如下：

• Standard Hosted Install，安装Calico用于现有的etcd群集。这是部署Calico在生产中推荐的托管方法；
• Kubeadm Hosted Install，安装Calico以及单个节点etcd群集。这是推荐的托管方法，与Calico一起快速入门，与kubeadm等工具结合使用；
• Kubernetes Datastore，不需要自己的etcd集群的模式安装Calico；

4.2 安装calico网络

等等......开始之前，先检查一下你的kubelet配置，是否启用 --network-plugin=cni 参数，如果没有赶紧加上。如果不加，你可能获取的一直都是docker0 分配的网段。

wget http://docs.projectcalico.org/v2.6/getting-started/kubernetes/installation/hosted/calico.yaml
sed -i 's@.*etcd_endpoints:.*@  etcd_endpoints: "https://192.168.15.131:2379,https://192.168.15.132:2379,https://192.168.15.133:2379"@gi' calico.yaml

export ETCD_CERT=`cat /etc/etcd/ssl/etcd.pem | base64 | tr -d '
'`
export ETCD_KEY=`cat /etc/etcd/ssl/etcd-key.pem | base64 | tr -d '
'`
export ETCD_CA=`cat /etc/etcd/ssl/etcd-root-ca.pem | base64 | tr -d '
'`


sed -i "s@.*etcd-cert:.*@  etcd-cert: ${ETCD_CERT}@gi" calico.yaml
sed -i "s@.*etcd-key:.*@  etcd-key: ${ETCD_KEY}@gi" calico.yaml
sed -i "s@.*etcd-ca:.*@  etcd-ca: ${ETCD_CA}@gi" calico.yaml

sed -i 's@.*etcd_ca:.*@  etcd_ca: "/calico-secrets/etcd-ca"@gi' calico.yaml
sed -i 's@.*etcd_cert:.*@  etcd_cert: "/calico-secrets/etcd-cert"@gi' calico.yaml
sed -i 's@.*etcd_key:.*@  etcd_key: "/calico-secrets/etcd-key"@gi' calico.yaml

sed -i 's@192.168.0.0/16@10.254.64.0/18@gi' calico.yaml

mkdir /data/kubernetes/calico -p
mv calico.yaml /data/kubernetes/calico/

提示：大陆访问gcr.io是访问不到，可以通过修改hosts文件实现，参考如下：

61.91.161.217 gcr.io
61.91.161.217 www.gcr.io
61.91.161.217 packages.cloud.google.com

# 启动pod

kubectl create -f /data/kubernetes/calico/calico.yaml
kubectl apply -f http://docs.projectcalico.org/v2.6/getting-started/kubernetes/installation/rbac.yaml

提示：可能由于网络等原因镜像下载较慢，导致pod无法正常启动，建议先将镜像下载到本地然后在启动。

# 验证网络

cat << EOF > demo.deploy.yml
apiVersion: apps/v1beta1
kind: Deployment
metadata:
  name: demo-deployment
spec:
  replicas: 3
  template:
    metadata:
      labels:
        app: demo
    spec:
      containers:
      - name: demo
        image: mritd/demo
        ports:
        - containerPort: 80
EOF
kubectl create -f demo.deploy.yml
kubetcl get pods -o wide --all-namespaces

提示：kubectl exec到某个pod内ping另一个不同node上的pod，此时每个node节点上都应有不同pod IP的路由。具体过程，这里就不做演示。

五、部署DNS

DNS 部署目前有两种方式，一种是纯手动，另一种是使用 Addon-manager，目前个人感觉 Addon-manager 有点繁琐，所以以下采取纯手动部署 DNS 组件。

5.1 部署DNS

DNS 组件相关文件位于 kubernetes addons 目录下，把相关文件下载下来然后稍作修改即可；

# 创建相关目录

mkdir /data/kubernetes/dns
cd  /data/kubernetes/dns

# 下载对应文件　　

wget https://raw.githubusercontent.com/kubernetes/kubernetes/release-1.7/cluster/addons/dns/kubedns-cm.yaml
wget https://raw.githubusercontent.com/kubernetes/kubernetes/release-1.7/cluster/addons/dns/kubedns-sa.yaml
wget https://raw.githubusercontent.com/kubernetes/kubernetes/release-1.7/cluster/addons/dns/kubedns-svc.yaml.sed
wget https://raw.githubusercontent.com/kubernetes/kubernetes/release-1.7/cluster/addons/dns/kubedns-controller.yaml.sed
mv kubedns-controller.yaml.sed kubedns-controller.yaml
mv kubedns-svc.yaml.sed kubedns-svc.yaml

# 修改配置　　

sed -i 's/$DNS_DOMAIN/cluster.local/gi' kubedns-controller.yaml
sed -i 's/$DNS_SERVER_IP/10.254.0.2/gi' kubedns-svc.yaml

提示：此 "DNS_SERVER_IP" 是你在 kubelet 配置文件中指定的地址，不是随便写的。

# 创建(我把所有 yml 放到的 dns 目录中)

kubectl create -f ./data/kubernetes/dns

# 验证

## 启动一个nginx pod 　

cat > my-nginx.yaml << EOF
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: my-nginx
spec:
  replicas: 2
  template:
    metadata:
      labels:
        run: my-nginx
    spec:
      containers:
      - name: my-nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80
EOF

kubectl create -f my-nginx.yaml

## export 该 Deployment, 生成 my-nginx 服务　　

kubectl expose deploy my-nginx

[root@k8s-master01 ~]# kubectl get services --all-namespaces |grep my-nginx
default       my-nginx     10.254.127.14   <none>        80/TCP          2s

## 创建另一个 Pod，查看 /etc/resolv.conf 是否包含 kubelet 配置的 --cluster-dns 和 --cluster-domain，是否能够将服务 my-nginx 解析到上面显示的 Cluster IP 10.254.127.14;　　

[root@k8s-master01 ~]# kubectl exec  nginx -i -t -- /bin/bash
root@nginx:/# cat /etc/resolv.conf
nameserver 10.254.0.2
search default.svc.cluster.local. svc.cluster.local. cluster.local. localhost
options ndots:5
root@nginx:/# ping my-nginx
PING my-nginx.default.svc.cluster.local (10.254.127.14): 48 data bytes
^C--- my-nginx.default.svc.cluster.local ping statistics ---
3 packets transmitted, 0 packets received, 100% packet loss
root@nginx:/# ping kubernetes
PING kubernetes.default.svc.cluster.local (10.254.0.1): 48 data bytes
^C--- kubernetes.default.svc.cluster.local ping statistics ---
5 packets transmitted, 0 packets received, 100% packet loss
root@nginx:/# ping kube-dns.kube-system.svc.cluster.local
PING kube-dns.kube-system.svc.cluster.local (10.254.0.2): 48 data bytes
^C--- kube-dns.kube-system.svc.cluster.local ping statistics ---
3 packets transmitted, 0 packets received, 100% packet loss

以上均能正常解析出IP地址，表明DNS服务正常；

5.2 自动伸缩DNS服务　　

# 创建项目目录

mkdir /data/kubernetes/dns-autoscaler
cd /data/kubernetes/dns-autoscaler/

# 下载文件　　

wget https://raw.githubusercontent.com/kubernetes/kubernetes/release-1.7/cluster/addons/dns-horizontal-autoscaler/dns-horizontal-autoscaler-rbac.yaml
wget https://raw.githubusercontent.com/kubernetes/kubernetes/release-1.7/cluster/addons/dns-horizontal-autoscaler/dns-horizontal-autoscaler.yaml

然后直接 kubectl create -f 即可，DNS 自动扩容计算公式为 replicas = max( ceil( cores * 1/coresPerReplica ) , ceil( nodes * 1/nodesPerReplica ) )，如果想调整 DNS 数量(负载因子)，只需要调整 ConfigMap 中对应参数即可，具体计算细节参考上面的官方文档;

# 编辑 Config Map

kubectl edit cm kube-dns-autoscaler --namespace=kube-system

提示：整个集群过程，可能存在镜像无法下载的情况。那么，你需要更镜像地址或者将镜像下载到本地。请注意镜像下载的问题，国内推荐阿里云容器镜像以及使用阿里云加速器下载dockerhub中镜像；