前面我们安装了一个简单的kubernetes集群，选用了1个master节点和三个node节点。etcd也没有安装成集群.
这次我们安装一个3个master节点+etcd集群的kubernetes集群.
节点规划
本次选用三个master节点，三个node节点来安装k8s集群。
etcd集群安装在master节点上.
并准备一个虚拟ip来做keepalived。
| 节点 | IP |
|---|---|
| M0 | 10.xx.xx.xx |
| M1 | 10.xx.xx.xx |
| M2 | 10.xx.xx.xx |
| N0 | 10.xx.xx.xx |
| N1 | 10.xx.xx.xx |
| N2 | 10.xx.xx.xx |
virtual_ipaddress： 10.xx.xx.xx
集群启动前的准备(请用root用户执行)
节点准备工作(在每台机器上执行)
包括修改主机名，关闭防火墙等操作。
k8s集群会识别主机名字，确保每个主机名设为不同值。
关闭防火墙是为了避免不必要的网络问题。
# ${hostname}变量请替换成规划的主机名，比如M0, N0, N1
sudo hostnamectl set-hostname ${hostname}
systemctl stop firewalld
systemctl disable firewalld
setenforce 0
sed -i -re '/^\s*SELINUX=/s/^/#/' -e '$i\\SELINUX=disabled' /etc/selinux/config建立ssh的互信，方便后面传文件什么的。可以使用ssh-copy-id命令快速建立，也可以自己手动建立。这个网上教程很多，自己搜一下
安装docker(在每台机器上执行)
yum install docker -y
systemctl enable docker && systemctl start docker修改docker的log driver为json-file,这个不影响安装，只是为了后期安装efk日志收集系统方便。 docker info可以查看当前log driver,centos7默认使用journald.
不同版本的docker可能修改方式不一样，最新官网文档是修改/etc/docker/daemon.json文件，我安装的版本是1.12.6，按如下方式修改。
vim /etc/sysconfig/docker
# 修改为如下，然后重启docker
OPTIONS='--selinux-enabled --log-driver=json-file --signature-verification=false'
systemctl restart docker安装kubeadm, kubelet, kubectl(每台机器上执行)
- kubeadm: 快速创建k8s集群的工具
- kubelet: k8s的基础组件，负责对pod和container的创建和管理，与k8s集群master建立联系
- kubectl: k8s的客户端工具，用来像集群发送命名
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
yum install -y kubelet kubeadm kubectl官网文档上写一些用户在RHEL/Centos7系统上安装时，由于iptables被绕过导致路由错误，需要在
sysctl的config文件中将net.bridge.bridge-nf-call-iptables设置为１.
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system启动kubelet:
systemctl enable kubelet && systemctl start kubelet至此，准备工作就做好了。目前每隔几秒kubelet就会重启，直到收到kubeadm的命令。
所以用systemctl status kubelet看到kubelet没有启动是正常现象，可以多执行几次查看，就会发现kubelet处于不断停止和重启的状态.
安装etcd集群(在三个master节点安装)
创建etcd CA证书
-
安装
cfssl和sfssljsoncurl -o /usr/local/bin/cfssl https://pkg.cfssl.org/R1.2/cfssl_linux-amd64 curl -o /usr/local/bin/cfssljson https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64 chmod +x /usr/local/bin/cfssl* -
ssh到etcd0节点(我这里规划的是master0节点)，执行下面命令
执行完成可以看到/etc/kubernetes/pki/etcd文件夹下生成了ca-config.json和ca-csr.json两个文件mkdir -p /etc/kubernetes/pki/etcd cd /etc/kubernetes/pki/etcd cat >ca-config.json <<EOF { "signing": { "default": { "expiry": "43800h" }, "profiles": { "server": { "expiry": "43800h", "usages": [ "signing", "key encipherment", "server auth", "client auth" ] }, "client": { "expiry": "43800h", "usages": [ "signing", "key encipherment", "client auth" ] }, "peer": { "expiry": "43800h", "usages": [ "signing", "key encipherment", "server auth", "client auth" ] } } } } EOF cat >ca-csr.json <<EOF { "CN": "etcd", "key": { "algo": "rsa", "size": 2048 } } EOF -
生成ca证书
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
生成etcd客户端证书
在etcd0节点执行以下操作,会生成两个文件client.pem， client-key.pem
cat >client.json <<EOF
{
"CN": "client",
"key": {
"algo": "ecdsa",
"size": 256
}
}
EOF
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=client client.json | cfssljson -bare client生成etcd的server和peer证书
-
设置PEER_NAME和PRIVATE_IP环境变量(在每台etcd机器上执行)
# 注意下面ens192是你实际网卡的名字，有可能是eth1之类的。用ip addr查看。 export PEER_NAME=$(hostname) export PRIVATE_IP=$(ip addr show ens192 | grep -Po 'inet \K[\d.]+') -
将刚刚在etcd上生成的CA拷贝到另外两台etcd机器上(在两台etch peers上执行)。
这里需要ssh信任权限，这个在上面已经让你建立好了。mkdir -p /etc/kubernetes/pki/etcd cd /etc/kubernetes/pki/etcd scp root@<etcd0-ip-address>:/etc/kubernetes/pki/etcd/ca.pem . scp root@<etcd0-ip-address>:/etc/kubernetes/pki/etcd/ca-key.pem . scp root@<etcd0-ip-address>:/etc/kubernetes/pki/etcd/client.pem . scp root@<etcd0-ip-address>:/etc/kubernetes/pki/etcd/client-key.pem . scp root@<etcd0-ip-address>:/etc/kubernetes/pki/etcd/ca-config.json . -
在所有etcd机器上执行下面命令，生成peer.pem, peer-key.pem, server.pem, server-key.pem
cfssl print-defaults csr > config.json sed -i '0,/CN/{s/example\.net/'"$PEER_NAME"'/}' config.json sed -i 's/www\.example\.net/'"$PRIVATE_IP"'/' config.json sed -i 's/example\.net/'"$PEER_NAME"'/' config.json cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=server config.json | cfssljson -bare server cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=peer config.json | cfssljson -bare peer
启动etcd集群(在每台etcd机器上执行)
这里有两种方式：在虚拟机上直接运行或在k8s上运行static pods.我这里选用第一种，在虚拟机上直接运行.
-
安装etcd
cd /tmp export ETCD_VERSION=v3.1.10 curl -sSL https://github.com/coreos/etcd/releases/download/${ETCD_VERSION}/etcd-${ETCD_VERSION}-linux-amd64.tar.gz | tar -xzv --strip-components=1 -C /usr/local/bin/ rm -rf etcd-$ETCD_VERSION-linux-amd64* -
生成etcd的环境文件，后面将会用到
touch /etc/etcd.env echo "PEER_NAME=$PEER_NAME" >> /etc/etcd.env echo "PRIVATE_IP=$PRIVATE_IP" >> /etc/etcd.env -
创建etcd服务systemd的配置文件
注意修改下面<etcd0-ip-address>等变量为虚拟机的真实ip地址。m0, m1等为etcd的名字cat >/etc/systemd/system/etcd.service <<EOF [Unit] Description=etcd Documentation=https://github.com/coreos/etcd Conflicts=etcd.service Conflicts=etcd2.service [Service] EnvironmentFile=/etc/etcd.env Type=notify Restart=always RestartSec=5s LimitNOFILE=40000 TimeoutStartSec=0 ExecStart=/usr/local/bin/etcd --name ${PEER_NAME} \ --data-dir /var/lib/etcd \ --listen-client-urls https://${PRIVATE_IP}:2379 \ --advertise-client-urls https://${PRIVATE_IP}:2379 \ --listen-peer-urls https://${PRIVATE_IP}:2380 \ --initial-advertise-peer-urls https://${PRIVATE_IP}:2380 \ --cert-file=/etc/kubernetes/pki/etcd/server.pem \ --key-file=/etc/kubernetes/pki/etcd/server-key.pem \ --client-cert-auth \ --trusted-ca-file=/etc/kubernetes/pki/etcd/ca.pem \ --peer-cert-file=/etc/kubernetes/pki/etcd/peer.pem \ --peer-key-file=/etc/kubernetes/pki/etcd/peer-key.pem \ --peer-client-cert-auth \ --peer-trusted-ca-file=/etc/kubernetes/pki/etcd/ca.pem \ --initial-cluster m0=https://<etcd0-ip-address>:2380,m1=https://<etcd1-ip-address>:2380,m2=https://<etcd2-ip-address>:2380 \ --initial-cluster-token my-etcd-token \ --initial-cluster-state new [Install] WantedBy=multi-user.target EOF -
启动etcd集群
systemctl daemon-reload systemctl start etcd
设置master节点的负载均衡器(keepalived,在三台master节点上执行)
-
安装keepalived
yum install keepalived -y -
修改配置文件
- state: 填写MASTER(主master节点m0)或BACKUP(其他master节点)
- interface: 填写网卡的名字(我这里是ens192)\
- priority: 权重，主master节点应该比其他节点高(比如m0填写101,其他节点填写100)
- auth_pass: 任意随机字符
- virtual_ipaddress: 应该填写为master节点准备的虚拟ip
! Configuration File for keepalived global_defs { router_id LVS_DEVEL } vrrp_script check_apiserver { script "/etc/keepalived/check_apiserver.sh" interval 3 weight -2 fall 10 rise 2 } vrrp_instance VI_1 { state <STATE> interface <INTERFACE> virtual_router_id 51 priority <PRIORITY> authentication { auth_type PASS auth_pass 4be37dc3b4c90194d1600c483e10ad1d } virtual_ipaddress { <VIRTUAL-IP> } track_script { check_apiserver } } -
健康检测脚本
将下面的<VIRTUAL-IP>替换成准备的虚拟ip#!/bin/sh errorExit() { echo "*** $*" 1>&2 exit 1 } curl --silent --max-time 2 --insecure https://localhost:6443/ -o /dev/null || errorExit "Error GET https://localhost:6443/" if ip addr | grep -q <VIRTUAL-IP>; then curl --silent --max-time 2 --insecure https://<VIRTUAL-IP>:6443/ -o /dev/null || errorExit "Error GET https://<VIRTUAL-IP>:6443/" fi -
启动keepalived
systemctl start keepalived
启动k8s集群
启动master0节点
-
生成配置文件：
- <private-ip>: 为master节点的IP地址
- <etcd0-ip>, <etcd1-ip>, <etcd2-ip> : etcd集群的ip地址
- <podCIDR>：POD CIDR，k8s的pod的网络模式。我这里选择flannel，即配置 为10.244.0.0/16。详细信息查看CNI network section
- 为了安装flannel,需要在每台机器上执行
sysctl net.bridge.bridge-nf-call-iptables=1
cat >config.yaml <<EOF apiVersion: kubeadm.k8s.io/v1alpha1 kind: MasterConfiguration api: advertiseAddress: <private-ip> etcd: endpoints: - https://<etcd0-ip-address>:2379 - https://<etcd1-ip-address>:2379 - https://<etcd2-ip-address>:2379 caFile: /etc/kubernetes/pki/etcd/ca.pem certFile: /etc/kubernetes/pki/etcd/client.pem keyFile: /etc/kubernetes/pki/etcd/client-key.pem networking: podSubnet: <podCIDR> apiServerCertSANs: - <load-balancer-ip> apiServerExtraArgs: apiserver-count: "3" EOF -
运行kubeadm
kubeadm init --config=config.yaml
启动master1, master2节点
-
将刚刚master0生成的文件copy到master1和master2机器
scp root@<master0-ip-address>:/etc/kubernetes/pki/ca.crt /etc/kubernetes/pki scp root@<master0-ip-address>:/etc/kubernetes/pki/ca.key /etc/kubernetes/pki scp root@<master0-ip-address>:/etc/kubernetes/pki/sa.key /etc/kubernetes/pki scp root@<master0-ip-address>:/etc/kubernetes/pki/sa.pub /etc/kubernetes/pki scp root@<master0-ip-address>:/etc/kubernetes/pki/front-proxy-ca.crt /etc/kubernetes/pki scp root@<master0-ip-address>:/etc/kubernetes/pki/front-proxy-ca.key /etc/kubernetes/pki scp -r root@<master0-ip-address>:/etc/kubernetes/pki/etcd /etc/kubernetes/pki - 重复master0的操作，生成config.yaml，运行kubeadm.
安装CNI网络
这里跟上面<podCIDR>那里设置的要对应起来。我这里选用的是Flannel,执行下面命令。
官网详解Installing a pod network
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.9.1/Documentation/kube-flannel.yml加入node节点
在每台node机器上执行以下格式的命令，在master节点执行完kubeadm init后会生成下面命令，复制执行就好。
这里统一将node加入到master0管理中。
kubeadm join --token <token> <master-ip>:<master-port> --discovery-token-ca-cert-hash sha256:<hash>完了可以使用kubectl get nodes查看集群是否安装完成。
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