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部署一套完整的Kubernetes高可用集群(上)

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部署一套完整的Kubernetes高可用集群(上)

一、前置知识点
1.1 生产环境可部署Kubernetes集群的两种方式目前生产部署Kubernetes集群主要有两种方式:
kubeadm
Kubeadm是一个K8s部署工具,提供kubeadm init和kubeadm join,用于快速部署Kubernetes集群。
官方地址:https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm/
二进制包
从github下载发行版的二进制包,手动部署每个组件,组成Kubernetes集群。
Kubeadm降低部署门槛,但屏蔽了很多细节,遇到问题很难排查。如果想更容易可控,推荐使用二进制包部署Kubernetes集群,虽然手动部署麻烦点,期间可以学习很多工作原理,也利于后期维护。
1.2 安装要求在开始之前,部署Kubernetes集群机器需要满足以下几个条件:
一台或多台机器,操作系统 CentOS7.x-86_x64
硬件配置:2GB或更多RAM,2个CPU或更多CPU,硬盘30GB或更多
集群中所有机器之间网络互通
可以访问外网,需要拉取镜像,如果服务器不能上网,需要提前下载镜像并导入节点
禁止swap分区
1.3 准备环境软件环境:
软件版本操作系统CentOS7.8_x64 (mini)Docker19-ceKubernetes1.18服务器整体规划:
角色IP组件k8s-master1192.168.31.71kube-apiserver,kube-controller-manager,kube-scheduler,etcdk8s-master2192.168.31.74kube-apiserver,kube-controller-manager,kube-schedulerk8s-node1192.168.31.72kubelet,kube-proxy,docker etcdk8s-node2192.168.31.73kubelet,kube-proxy,docker,etcdLoad Balancer(Master)192.168.31.81 ,192.168.31.88 (VIP)Nginx L4Load Balancer(Backup)192.168.31. 82Nginx L4须知:考虑到有些朋友电脑配置较低,这么多虚拟机跑不动,所以这一套高可用集群分两部分实施,先部署一套单Master架构(192.168.31.71/72/73),再扩容为多Master架构(上述规划),顺便熟悉下Master扩容流程。
单Master架构图:
部署一套完整的Kubernetes高可用集群(上)
单Master服务器规划:
角色IP组件k8s-master192.168.31.71kube-apiserver,kube-controller-manager,kube-scheduler,etcdk8s-node1192.168.31.72kubelet,kube-proxy,docker etcdk8s-node2192.168.31.73kubelet,kube-proxy,docker,etcd1.4 操作系统初始化配置# 关闭防火墙
systemctl stop firewalld
systemctl disable firewalld

# 关闭selinux
sed -i ‘s/enforcing/disabled/’ /etc/selinux/config # 永久
setenforce 0 # 临时

# 关闭swap
swapoff -a # 临时
sed -ri ‘s/.*swap.*/#&/’ /etc/fstab # 永久

# 根据规划设置主机名
hostnamectl set-hostname <hostname>

# 在master添加hosts
cat >> /etc/hosts << EOF
192.168.31.71 k8s-master
192.168.31.72 k8s-node1
192.168.31.73 k8s-node2
EOF

# 将桥接的IPv4流量传递到iptables的链
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl –system # 生效


# 时间同步
yum install ntpdate -y
ntpdate time.windows.com
二、部署Etcd集群Etcd 是一个分布式键值存储系统,Kubernetes使用Etcd进行数据存储,所以先准备一个Etcd数据库,为解决Etcd单点故障,应采用集群方式部署,这里使用3台组建集群,可容忍1台机器故障,当然,你也可以使用5台组建集群,可容忍2台机器故障。
节点名称IPetcd-1192.168.31.71etcd-2192.168.31.72etcd-3192.168.31.73注:为了节省机器,这里与K8s节点机器复用。也可以独立于k8s集群之外部署,只要apiserver能连接到就行。
2.1 准备cfssl证书生成工具cfssl是一个开源的证书管理工具,使用json文件生成证书,相比openssl更方便使用。
找任意一台服务器操作,这里用Master节点。
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/bin/cfssl-certinfo
2.2 生成Etcd证书1. 自签证书颁发机构(CA)创建工作目录:
mkdir -p ~/TLS/{etcd,k8s}


cd TLS/etcd
自签CA:
cat > ca-config.json << EOF
{
"signing": {
"default": {
"expiry": "87600h"
},
"profiles": {
"www": {
"expiry": "87600h",
"usages": [
"signing",
"key encipherment",
"server auth",
"client auth"
]
}
}
}
}
EOF


cat > ca-csr.json << EOF
{
"CN": "etcd CA",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "Beijing",
"ST": "Beijing"
}
]
}
EOF
生成证书:
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -


ls *pem
ca-key.pem ca.pem
2. 使用自签CA签发Etcd HTTPS证书创建证书申请文件:
cat > server-csr.json << EOF
{
"CN": "etcd",
"hosts": [
"192.168.31.71",
"192.168.31.72",
"192.168.31.73"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing"
}
]
}
EOF


注:上述文件hosts字段中IP为所有etcd节点的集群内部通信IP,一个都不能少!为了方便后期扩容可以多写几个预留的IP。
生成证书:
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server


ls server*pem
server-key.pem server.pem
2.3 从Github下载二进制文件下载地址:https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz
2.4 部署Etcd集群以下在节点1上操作,为简化操作,待会将节点1生成的所有文件拷贝到节点2和节点3.
1. 创建工作目录并解压二进制包mkdir /opt/etcd/{bin,cfg,ssl} -p
tar zxvf etcd-v3.4.9-linux-amd64.tar.gz
mv etcd-v3.4.9-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/
2. 创建etcd配置文件cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.71:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF
ETCD_NAME:节点名称,集群中唯一
ETCD_DATA_DIR:数据目录
ETCD_LISTEN_PEER_URLS:集群通信监听地址
ETCD_LISTEN_CLIENT_URLS:客户端访问监听地址
ETCD_INITIAL_ADVERTISE_PEER_URLS:集群通告地址
ETCD_ADVERTISE_CLIENT_URLS:客户端通告地址
ETCD_INITIAL_CLUSTER:集群节点地址
ETCD_INITIAL_CLUSTER_TOKEN:集群Token
ETCD_INITIAL_CLUSTER_STATE:加入集群的当前状态,new是新集群,existing表示加入已有集群
3. systemd管理etcdcat > /usr/lib/systemd/system/etcd.service << EOF
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd.conf
ExecStart=/opt/etcd/bin/etcd
--cert-file=/opt/etcd/ssl/server.pem
--key-file=/opt/etcd/ssl/server-key.pem
--peer-cert-file=/opt/etcd/ssl/server.pem
--peer-key-file=/opt/etcd/ssl/server-key.pem
--trusted-ca-file=/opt/etcd/ssl/ca.pem
--peer-trusted-ca-file=/opt/etcd/ssl/ca.pem
--logger=zap
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
4. 拷贝刚才生成的证书把刚才生成的证书拷贝到配置文件中的路径:
cp ~/TLS/etcd/ca*pem ~/TLS/etcd/server*pem /opt/etcd/ssl/
5. 启动并设置开机启动systemctl daemon-reload
systemctl start etcd
systemctl enable etcd
6. 将上面节点1所有生成的文件拷贝到节点2和节点3scp -r /opt/etcd/ root@192.168.31.72:/opt/
scp /usr/lib/systemd/system/etcd.service root@192.168.31.72:/usr/lib/systemd/system/
scp -r /opt/etcd/ root@192.168.31.73:/opt/
scp /usr/lib/systemd/system/etcd.service root@192.168.31.73:/usr/lib/systemd/system/
然后在节点2和节点3分别修改etcd.conf配置文件中的节点名称和当前服务器IP:
vi /opt/etcd/cfg/etcd.conf
#[Member]
ETCD_NAME="etcd-1" # 修改此处,节点2改为etcd-2,节点3改为etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.71:2380" # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379" # 修改此处为当前服务器IP


#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379" # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
最后启动etcd并设置开机启动,同上。
7. 查看集群状态ETCDCTL_API=3 /opt/etcd/bin/etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379" endpoint health


https://192.168.31.71:2379 is healthy: successfully committed proposal: took = 8.154404ms
https://192.168.31.73:2379 is healthy: successfully committed proposal: took = 9.044117ms
https://192.168.31.72:2379 is healthy: successfully committed proposal: took = 10.000825ms
如果输出上面信息,就说明集群部署成功。如果有问题第一步先看日志:/var/log/message 或 journalctl -u etcd
三、安装Docker下载地址:https://download.docker.com/linux/static/stable/x86_64/docker-19.03.9.tgz
以下在所有节点操作。这里采用二进制安装,用yum安装也一样。
3.1 解压二进制包tar zxvf docker-19.03.9.tgz
mv docker/* /usr/bin
3.2 systemd管理dockercat > /usr/lib/systemd/system/docker.service << EOF
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target
[Service]
Type=notify
ExecStart=/usr/bin/dockerd
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TimeoutStartSec=0
Delegate=yes
KillMode=process
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s
[Install]
WantedBy=multi-user.target
EOF
3.3 创建配置文件mkdir /etc/docker
cat > /etc/docker/daemon.json << EOF
{
"registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF
registry-mirrors 阿里云镜像加速器
3.4 启动并设置开机启动systemctl daemon-reload
systemctl start docker
systemctl enable docker
四、部署Master Node如果你在学习中遇到问题或者文档有误可联系阿良~ 微信: init1024
4.1 生成kube-apiserver证书1. 自签证书颁发机构(CA)cat > ca-config.json << EOF
{
"signing": {
"default": {
"expiry": "87600h"
},
"profiles": {
"kubernetes": {
"expiry": "87600h",
"usages": [
"signing",
"key encipherment",
"server auth",
"client auth"
]
}
}
}
}
EOF
cat > ca-csr.json << EOF
{
"CN": "kubernetes",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "Beijing",
"ST": "Beijing",
"O": "k8s",
"OU": "System"
}
]
}
EOF
生成证书:
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -


ls *pem
ca-key.pem ca.pem
2. 使用自签CA签发kube-apiserver HTTPS证书创建证书申请文件:
cd TLS/k8s
cat > server-csr.json << EOF
{
"CN": "kubernetes",
"hosts": [
"10.0.0.1",
"127.0.0.1",
"192.168.31.71",
"192.168.31.72",
"192.168.31.73",
"192.168.31.74",
"192.168.31.81",
"192.168.31.82",
"192.168.31.88",
"kubernetes",
"kubernetes.default",
"kubernetes.default.svc",
"kubernetes.default.svc.cluster",
"kubernetes.default.svc.cluster.local"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing",
"O": "k8s",
"OU": "System"
}
]
}
EOF
注:上述文件hosts字段中IP为所有Master/LB/VIP IP,一个都不能少!为了方便后期扩容可以多写几个预留的IP。
生成证书:
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare server


ls server*pem
server-key.pem server.pem
4.2 从Github下载二进制文件下载地址: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md#v1183
注:打开链接你会发现里面有很多包,下载一个server包就够了,包含了Master和Worker Node二进制文件。
4.3 解压二进制包mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}
tar zxvf kubernetes-server-linux-amd64.tar.gz
cd kubernetes/server/bin
cp kube-apiserver kube-scheduler kube-controller-manager /opt/kubernetes/bin
cp kubectl /usr/bin/
4.4 部署kube-apiserver1. 创建配置文件cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \
--v=2 \
--log-dir=/opt/kubernetes/logs \
--etcd-servers=https://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379 \
--bind-address=192.168.31.71 \
--secure-port=6443 \
--advertise-address=192.168.31.71 \
--allow-privileged=true \
--service-cluster-ip-range=10.0.0.0/24 \
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \
--authorization-mode=RBAC,Node \
--enable-bootstrap-token-auth=true \
--token-auth-file=/opt/kubernetes/cfg/token.csv \
--service-node-port-range=30000-32767 \
--kubelet-client-certificate=/opt/kubernetes/ssl/server.pem \
--kubelet-client-key=/opt/kubernetes/ssl/server-key.pem \
--tls-cert-file=/opt/kubernetes/ssl/server.pem \
--tls-private-key-file=/opt/kubernetes/ssl/server-key.pem \
--client-ca-file=/opt/kubernetes/ssl/ca.pem \
--service-account-key-file=/opt/kubernetes/ssl/ca-key.pem \
--etcd-cafile=/opt/etcd/ssl/ca.pem \
--etcd-certfile=/opt/etcd/ssl/server.pem \
--etcd-keyfile=/opt/etcd/ssl/server-key.pem \
--audit-log-maxage=30 \
--audit-log-maxbackup=3 \
--audit-log-maxsize=100 \
--audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
EOF
注:上面两个 第一个是转义符,第二个是换行符,使用转义符是为了使用EOF保留换行符。
–logtostderr:启用日志
—v:日志等级
–log-dir:日志目录
–etcd-servers:etcd集群地址
–bind-address:监听地址
–secure-port:https安全端口
–advertise-address:集群通告地址
–allow-privileged:启用授权
–service-cluster-ip-range:Service虚拟IP地址段
–enable-admission-plugins:准入控制模块
–authorization-mode:认证授权,启用RBAC授权和节点自管理
–enable-bootstrap-token-auth:启用TLS bootstrap机制
–token-auth-file:bootstrap token文件
–service-node-port-range:Service nodeport类型默认分配端口范围
–kubelet-client-xxx:apiserver访问kubelet客户端证书
–tls-xxx-file:apiserver https证书
–etcd-xxxfile:连接Etcd集群证书
–audit-log-xxx:审计日志
2. 拷贝刚才生成的证书把刚才生成的证书拷贝到配置文件中的路径:
cp ~/TLS/k8s/ca*pem ~/TLS/k8s/server*pem /opt/kubernetes/ssl/
3. 启用 TLS Bootstrapping 机制TLS Bootstraping:Master apiserver启用TLS认证后,Node节点kubelet和kube-proxy要与kube-apiserver进行通信,必须使用CA签发的有效证书才可以,当Node节点很多时,这种客户端证书颁发需要大量工作,同样也会增加集群扩展复杂度。为了简化流程,Kubernetes引入了TLS bootstraping机制来自动颁发客户端证书,kubelet会以一个低权限用户自动向apiserver申请证书,kubelet的证书由apiserver动态签署。所以强烈建议在Node上使用这种方式,目前主要用于kubelet,kube-proxy还是由我们统一颁发一个证书。
TLS bootstraping 工作流程:
部署一套完整的Kubernetes高可用集群(上)
创建上述配置文件中token文件:
cat > /opt/kubernetes/cfg/token.csv << EOF
c47ffb939f5ca36231d9e3121a252940,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF
格式:token,用户名,UID,用户组
token也可自行生成替换:
head -c 16 /dev/urandom | od -An -t x | tr -d ' '
4. systemd管理apiservercat > /usr/lib/systemd/system/kube-apiserver.service << EOF
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-apiserver.conf
ExecStart=/opt/kubernetes/bin/kube-apiserver $KUBE_APISERVER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
5. 启动并设置开机启动systemctl daemon-reload
systemctl start kube-apiserver
systemctl enable kube-apiserver
6. 授权kubelet-bootstrap用户允许请求证书kubectl create clusterrolebinding kubelet-bootstrap
--clusterrole=system:node-bootstrapper
--user=kubelet-bootstrap
4.5 部署kube-controller-manager1. 创建配置文件cat > /opt/kubernetes/cfg/kube-controller-manager.conf << EOF
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=false \
--v=2 \
--log-dir=/opt/kubernetes/logs \
--leader-elect=true \
--master=127.0.0.1:8080 \
--bind-address=127.0.0.1 \
--allocate-node-cidrs=true \
--cluster-cidr=10.244.0.0/16 \
--service-cluster-ip-range=10.0.0.0/24 \
--cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem \
--cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem \
--root-ca-file=/opt/kubernetes/ssl/ca.pem \
--service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem \
--experimental-cluster-signing-duration=87600h0m0s"
EOF
–master:通过本地非安全本地端口8080连接apiserver。
–leader-elect:当该组件启动多个时,自动选举(HA)
–cluster-signing-cert-file/–cluster-signing-key-file:自动为kubelet颁发证书的CA,与apiserver保持一致
2. systemd管理controller-managercat > /usr/lib/systemd/system/kube-controller-manager.service << EOF
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-controller-manager.conf
ExecStart=/opt/kubernetes/bin/kube-controller-manager $KUBE_CONTROLLER_MANAGER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
3. 启动并设置开机启动systemctl daemon-reload
systemctl start kube-controller-manager
systemctl enable kube-controller-manager
4.6 部署kube-scheduler1. 创建配置文件cat > /opt/kubernetes/cfg/kube-scheduler.conf << EOF
KUBE_SCHEDULER_OPTS="--logtostderr=false
--v=2
--log-dir=/opt/kubernetes/logs
--leader-elect
--master=127.0.0.1:8080
--bind-address=127.0.0.1"
EOF
–master:通过本地非安全本地端口8080连接apiserver。
–leader-elect:当该组件启动多个时,自动选举(HA)
2. systemd管理schedulercat > /usr/lib/systemd/system/kube-scheduler.service << EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-scheduler.conf
ExecStart=/opt/kubernetes/bin/kube-scheduler $KUBE_SCHEDULER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
3. 启动并设置开机启动systemctl daemon-reload
systemctl start kube-scheduler
systemctl enable kube-scheduler
4. 查看集群状态所有组件都已经启动成功,通过kubectl工具查看当前集群组件状态:
kubectl get cs
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-2 Healthy {"health":"true"}
etcd-1 Healthy {"health":"true"}
etcd-0 Healthy {"health":"true"}
如上输出说明Master节点组件运行正常。
五、部署Worker Node如果你在学习中遇到问题或者文档有误可联系阿良~ 微信: init1024
下面还是在Master Node上操作,即同时作为Worker Node

5.1 创建工作目录并拷贝二进制文件在所有worker node创建工作目录:
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}
从master节点拷贝:
cd kubernetes/server/bin
cp kubelet kube-proxy /opt/kubernetes/bin # 本地拷贝
5.2 部署kubelet1. 创建配置文件cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \
--v=2 \
--log-dir=/opt/kubernetes/logs \
--hostname-override=k8s-master \
--network-plugin=cni \
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \
--config=/opt/kubernetes/cfg/kubelet-config.yml \
--cert-dir=/opt/kubernetes/ssl \
--pod-infra-container-image=lizhenliang/pause-amd64:3.0"
EOF
–hostname-override:显示名称,集群中唯一
–network-plugin:启用CNI
–kubeconfig:空路径,会自动生成,后面用于连接apiserver
–bootstrap-kubeconfig:首次启动向apiserver申请证书
–config:配置参数文件
–cert-dir:kubelet证书生成目录
–pod-infra-container-image:管理Pod网络容器的镜像
2. 配置参数文件cat > /opt/kubernetes/cfg/kubelet-config.yml << EOF
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 0.0.0.0
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS:
- 10.0.0.2
clusterDomain: cluster.local
failSwapOn: false
authentication:
anonymous:
enabled: false
webhook:
cacheTTL: 2m0s
enabled: true
x509:
clientCAFile: /opt/kubernetes/ssl/ca.pem
authorization:
mode: Webhook
webhook:
cacheAuthorizedTTL: 5m0s
cacheUnauthorizedTTL: 30s
evictionHard:
imagefs.available: 15%
memory.available: 100Mi
nodefs.available: 10%
nodefs.inodesFree: 5%
maxOpenFiles: 1000000
maxPods: 110
EOF
3. 生成bootstrap.kubeconfig文件KUBE_APISERVER="https://192.168.31.71:6443" # apiserver IP:PORT
TOKEN="c47ffb939f5ca36231d9e3121a252940" # 与token.csv里保持一致


# 生成 kubelet bootstrap kubeconfig 配置文件
kubectl config set-cluster kubernetes
--certificate-authority=/opt/kubernetes/ssl/ca.pem
--embed-certs=true
--server=${KUBE_APISERVER}
--kubeconfig=bootstrap.kubeconfig
kubectl config set-credentials "kubelet-bootstrap"
--token=${TOKEN}
--kubeconfig=bootstrap.kubeconfig
kubectl config set-context default
--cluster=kubernetes
--user="kubelet-bootstrap"
--kubeconfig=bootstrap.kubeconfig
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig
拷贝到配置文件路径:
cp bootstrap.kubeconfig /opt/kubernetes/cfg
4. systemd管理kubeletcat > /usr/lib/systemd/system/kubelet.service << EOF
[Unit]
Description=Kubernetes Kubelet
After=docker.service
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kubelet.conf
ExecStart=/opt/kubernetes/bin/kubelet $KUBELET_OPTS
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
5. 启动并设置开机启动systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet
5.3 批准kubelet证书申请并加入集群# 查看kubelet证书请求
kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A 6m3s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending

# 批准申请
kubectl certificate approve node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ–K6M4G7bjhk8A


# 查看节点
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master NotReady <none> 7s v1.18.3
注:由于网络插件还没有部署,节点会没有准备就绪 NotReady
5.4 部署kube-proxy1. 创建配置文件cat > /opt/kubernetes/cfg/kube-proxy.conf << EOF
KUBE_PROXY_OPTS="--logtostderr=false \
--v=2 \
--log-dir=/opt/kubernetes/logs \
--config=/opt/kubernetes/cfg/kube-proxy-config.yml"
EOF
2. 配置参数文件cat > /opt/kubernetes/cfg/kube-proxy-config.yml << EOF
kind: KubeProxyConfiguration
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 0.0.0.0
metricsBindAddress: 0.0.0.0:10249
clientConnection:
kubeconfig: /opt/kubernetes/cfg/kube-proxy.kubeconfig
hostnameOverride: k8s-master
clusterCIDR: 10.0.0.0/24
EOF
3. 生成kube-proxy.kubeconfig文件生成kube-proxy证书:
# 切换工作目录
cd TLS/k8s

# 创建证书请求文件
cat > kube-proxy-csr.json << EOF
{
“CN”: “system:kube-proxy”,
“hosts”: [],
“key”: {
“algo”: “rsa”,
“size”: 2048
},
“names”: [
{
“C”: “CN”,
“L”: “BeiJing”,
“ST”: “BeiJing”,
“O”: “k8s”,
“OU”: “System”
}
]
}
EOF

# 生成证书
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy


ls kube-proxy*pem
kube-proxy-key.pem kube-proxy.pem
生成kubeconfig文件:
KUBE_APISERVER="https://192.168.31.71:6443"


kubectl config set-cluster kubernetes
--certificate-authority=/opt/kubernetes/ssl/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
拷贝到配置文件指定路径:
cp kube-proxy.kubeconfig /opt/kubernetes/cfg/
4. systemd管理kube-proxycat > /usr/lib/systemd/system/kube-proxy.service << EOF
[Unit]
Description=Kubernetes Proxy
After=network.target
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-proxy.conf
ExecStart=/opt/kubernetes/bin/kube-proxy $KUBE_PROXY_OPTS
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
5. 启动并设置开机启动systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy
5.5 部署CNI网络先准备好CNI二进制文件:
下载地址:https://github.com/containernetworking/plugins/releases/download/v0.8.6/cni-plugins-linux-amd64-v0.8.6.tgz
解压二进制包并移动到默认工作目录:
mkdir /opt/cni/bin
tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin
部署CNI网络:
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
sed -i -r "s#quay.io/coreos/flannel:.*-amd64#lizhenliang/flannel:v0.12.0-amd64#g" kube-flannel.yml
默认镜像地址无法访问,修改为docker hub镜像仓库。
kubectl apply -f kube-flannel.yml

kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
kube-flannel-ds-amd64-2pc95 1/1 Running 0 72s


kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master Ready <none> 41m v1.18.3
部署好网络插件,Node准备就绪。
5.6 授权apiserver访问kubeletcat > apiserver-to-kubelet-rbac.yaml << EOF
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
annotations:
rbac.authorization.kubernetes.io/autoupdate: "true"
labels:
kubernetes.io/bootstrapping: rbac-defaults
name: system:kube-apiserver-to-kubelet
rules:
- apiGroups:
- ""
resources:
- nodes/proxy
- nodes/stats
- nodes/log
- nodes/spec
- nodes/metrics
- pods/log
verbs:
- "*"
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: system:kube-apiserver
namespace: ""
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: system:kube-apiserver-to-kubelet
subjects:
- apiGroup: rbac.authorization.k8s.io
kind: User
name: kubernetes
EOF


kubectl apply -f apiserver-to-kubelet-rbac.yaml
5.7 新增加Worker Node1. 拷贝已部署好的Node相关文件到新节点在master节点将Worker Node涉及文件拷贝到新节点192.168.31.72/73
scp -r /opt/kubernetes root@192.168.31.72:/opt/

scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.31.72:/usr/lib/systemd/system

scp -r /opt/cni/ root@192.168.31.72:/opt/


scp /opt/kubernetes/ssl/ca.pem root@192.168.31.72:/opt/kubernetes/ssl
2. 删除kubelet证书和kubeconfig文件rm /opt/kubernetes/cfg/kubelet.kubeconfig
rm -f /opt/kubernetes/ssl/kubelet*
注:这几个文件是证书申请审批后自动生成的,每个Node不同,必须删除重新生成。
3. 修改主机名vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node1


vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-node1
4. 启动并设置开机启动systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet
systemctl start kube-proxy
systemctl enable kube-proxy
5. 在Master上批准新Node kubelet证书申请kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro 89s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending


kubectl certificate approve node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro
6. 查看Node状态kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master Ready <none> 65m v1.18.3
k8s-node1 Ready <none> 12m v1.18.3
k8s-node2 Ready <none> 81s v1.18.3
Node2(192.168.31.73 )节点同上。记得修改主机名!
六、部署Dashboard和CoreDNS6.1 部署Dashboard$ wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta8/aio/deploy/recommended.yaml
默认Dashboard只能集群内部访问,修改Service为NodePort类型,暴露到外部:
vi recommended.yaml
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kubernetes-dashboard
spec:
ports:
- port: 443
targetPort: 8443
nodePort: 30001
type: NodePort
selector:
k8s-app: kubernetes-dashboard


kubectl apply -f recommended.yaml
kubectl get pods,svc -n kubernetes-dashboard
NAME READY STATUS RESTARTS AGE
pod/dashboard-metrics-scraper-694557449d-z8gfb 1/1 Running 0 2m18s
pod/kubernetes-dashboard-9774cc786-q2gsx 1/1 Running 0 2m19s


NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/dashboard-metrics-scraper ClusterIP 10.0.0.141 <none> 8000/TCP 2m19s
service/kubernetes-dashboard NodePort 10.0.0.239 <none> 443:30001/TCP 2m19s
访问地址:https://NodeIP:30001
创建service account并绑定默认cluster-admin管理员集群角色:
kubectl create serviceaccount dashboard-admin -n kube-system
kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')
使用输出的token登录Dashboard。
部署一套完整的Kubernetes高可用集群(上)
部署一套完整的Kubernetes高可用集群(上)
6.2 部署CoreDNSCoreDNS用于集群内部Service名称解析。
kubectl apply -f coredns.yaml


kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-5ffbfd976d-j6shb 1/1 Running 0 32s
kube-flannel-ds-amd64-2pc95 1/1 Running 0 38m
kube-flannel-ds-amd64-7qhdx 1/1 Running 0 15m
kube-flannel-ds-amd64-99cr8 1/1 Running 0 26m
DNS解析测试:
kubectl run -it --rm dns-test --image=busybox:1.28.4 sh
If you don't see a command prompt, try pressing enter.

/ # nslookup kubernetes
Server: 10.0.0.2
Address 1: 10.0.0.2 kube-dns.kube-system.svc.cluster.local


Name: kubernetes
Address 1: 10.0.0.1 kubernetes.default.svc.cluster.local
解析没问题。
至此,单Master集群部署完成,下一篇扩容为多Master集群~

原文始发于微信公众号(DevOps技术栈):部署一套完整的Kubernetes高可用集群(上)

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