注:该文来源于李振良老师。
《部署一套完整的企业级K8s集群》
v1.20,二进制方式
作者信息 |
李振良(阿良),微信:xyz12366699 |
DevOps实战学院 |
|
说明 |
该文档有导航窗格,方便阅读,如果左侧没有显示,请检查word是否启用。 转载请注明作者,拒绝不道德行为! |
最后更新时间 |
2021-04-06 |
目录
4.5 部署kube-controller-manager.. 20
7.2 部署Nginx+Keepalived高可用负载均衡器.... 47
7.3 修改所有Worker Node连接LB VIP.. 54
一、前置知识点
1.1 生产环境部署K8s集群的两种方式
- 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。
- 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。
小结: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 准备环境
服务器要求:
- 建议最小硬件配置:2核CPU、2G内存、30G硬盘
- 服务器最好可以访问外网,会有从网上拉取镜像需求,如果服务器不能上网,需要提前下载对应镜像并导入节点
软件环境:
软件 |
版本 |
操作系统 |
CentOS7.x_x64 (mini) |
容器引擎 |
Docker CE 19 |
Kubernetes |
Kubernetes v1.20 |
服务器整体规划:
角色 |
IP |
组件 |
k8s-master01 |
192.168.31.71 |
kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker,etcd, nginx,keepalived |
k8s-master2 |
192.168.31.74 |
kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker, nginx,keepalived |
k8s-node1 |
192.168.31.72 |
kubelet,kube-proxy,docker,etcd |
k8s-node2 |
192.168.31.73 |
kubelet,kube-proxy,docker,etcd |
负载均衡器IP |
192.168.31.88 (VIP) |
须知:考虑到有些朋友电脑配置较低,一次性开四台机器会跑不动,所以搭建这套K8s高可用集群分两部分实施,先部署一套单Master架构(3台),再扩容为多Master架构(4台或6台),顺便再熟悉下Master扩容流程。
单Master架构图:
单Master服务器规划:
角色 |
IP |
组件 |
k8s-master |
192.168.31.71 |
kube-apiserver,kube-controller-manager,kube-scheduler,etcd |
k8s-node1 |
192.168.31.72 |
kubelet,kube-proxy,docker,etcd |
k8s-node2 |
192.168.31.73 |
kubelet,kube-proxy,docker,etcd |
1.3 操作系统初始化配置
以上三台服务器同样操作~~~
# 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 192.168.16.80 k8s-master01
192.168.16.81 k8s-master02
192.168.16.82 k8s-node01
192.168.16.83 k8s-node02 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
ntpdate cn.pool.ntp.org
crontab -l
0 5 * * * /usr/sbin/ntpdate -u cn.pool.ntp.org
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 |
IP |
etcd-1 |
192.168.31.71 |
etcd-2 |
192.168.31.72 |
etcd-3 |
192.168.31.73 |
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 -
会生成ca.pem和ca-key.pem文件。
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": [
"192.168.16.80",
"192.168.16.81",
"192.168.16.82",
"192.168.16.83",
"192.168.16.90"
],
"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
会生成server.pem和server-key.pem文件。
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/
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_PEERURLS: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_INITIALCLUSTER_TOKEN:集群Token
- ETCD_INITIALCLUSTER_STATE:加入集群的当前状态,new是新集群,existing表示加入已有集群
cat > /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/
systemctl start etcd
systemctl enable etcd
scp -r /opt/etcd/ [email protected]:/opt/
scp /usr/lib/systemd/system/etcd.service [email protected]:/usr/lib/systemd/system/
scp -r /opt/etcd/ [email protected]:/opt/
scp /usr/lib/systemd/system/etcd.service [email protected]:/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。
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://192.168.16.80:2379,https://192.168.16.82:2379,https://192.168.16.83:2379" endpoint health --write-out=table
+----------------------------+--------+-------------+-------+
| ENDPOINT | HEALTH | TOOK | ERROR |
+----------------------------+--------+-------------+-------+
| https://192.168.31.71:2379 | true | 10.301506ms | |
| https://192.168.31.73:2379 | true | 12.87467ms | |
| https://192.168.31.72:2379 | true | 13.225954ms | |
+----------------------------+--------+-------------+-------+
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
这里使用Docker作为容器引擎,也可以换成别的,例如containerd
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
[root@k8s-master01 DOCKER]# chown -R root.root docker mv docker/* /usr/bin
3.2 systemd管理docker
cat > /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: xyz12366699
4.1 生成kube-apiserver证书
cd ~/TLS/k8s
[root@k8s-master01 k8s]# mkdir kube-apiserver 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 -
会生成ca.pem和ca-key.pem文件。还有ca.csr文件
2. 使用自签CA签发kube-apiserver HTTPS证书
创建证书申请文件:
cat > server-csr.json << EOF
{
"CN": "kubernetes",
"hosts": [
"10.0.0.1",
"127.0.0.1",
"192.168.16.80",
"192.168.16.81",
"192.168.16.82",
"192.168.16.83", "192.168.16.90", "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
会生成server.pem和server-key.pem文件。还有server.csr文件。
4.2 从Github下载二进制文件
下载地址: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.20.md
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-apiserver
cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--etcd-servers=https://192.168.16.80:2379,https://192.168.16.82:2379,https://192.168.16.83:2379 \\
--bind-address=192.168.16.80 \\
--secure-port=6443 \\
--advertise-address=192.168.16.80 \\
--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 \\
--service-account-issuer=api \\
--service-account-signing-key-file=/opt/kubernetes/ssl/server-key.pem \\
--etcd-cafile=/opt/etcd/ssl/ca.pem \\
--etcd-certfile=/opt/etcd/ssl/server.pem \\
--etcd-keyfile=/opt/etcd/ssl/server-key.pem \\
--requestheader-client-ca-file=/opt/kubernetes/ssl/ca.pem \\
--proxy-client-cert-file=/opt/kubernetes/ssl/server.pem \\
--proxy-client-key-file=/opt/kubernetes/ssl/server-key.pem \\
--requestheader-allowed-names=kubernetes \\
--requestheader-extra-headers-prefix=X-Remote-Extra- \\
--requestheader-group-headers=X-Remote-Group \\
--requestheader-username-headers=X-Remote-User \\
--enable-aggregator-routing=true \\
--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
- 1.20版本必须加的参数:--service-account-issuer,--service-account-signing-key-file
- --etcd-xxxfile:连接Etcd集群证书
- --audit-log-xxx:审计日志
- 启动聚合层相关配置:--requestheader-client-ca-file,--proxy-client-cert-file,--proxy-client-key-file,--requestheader-allowed-names,--requestheader-extra-headers-prefix,--requestheader-group-headers,--requestheader-username-headers,--enable-aggregator-routing
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/
cp ~/TLS/k8s/kube-apiserver/ca*pem ~/TLS/k8s/kube-apiserver/server*pem /opt/kubernetes/ssl/
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:
创建上述配置文件中token文件:
cat > /opt/kubernetes/cfg/token.csv << EOF
bfe8e191df6b2afaf9cc9e83f78b5d50,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 ' '
bfe8e191df6b2afaf9cc9e83f78b5d50
cat > /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
systemctl daemon-reload
systemctl start kube-apiserver
systemctl enable kube-apiserver
4.5 部署kube-controller-manager
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 \\
--kubeconfig=/opt/kubernetes/cfg/kube-controller-manager.kubeconfig \\
--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 \\
--cluster-signing-duration=87600h0m0s"
EOF
- --kubeconfig:连接apiserver配置文件
- --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
生成kube-controller-manager证书:
# 切换工作目录 cd ~/TLS/k8s # 创建证书请求文件 cat > kube-controller-manager-csr.json << EOF { "CN": "system:kube-controller-manager", "hosts": [], "key": { "algo": "rsa", "size": 2048 }, "names": [ { "C": "CN", "L": "BeiJing", "ST": "BeiJing", "O": "system:masters", "OU": "System" } ] } EOF # 生成证书 cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager
生成kubeconfig文件(以下是shell命令,直接在终端执行):
KUBE_CONFIG="/opt/kubernetes/cfg/kube-controller-manager.kubeconfig"
KUBE_APISERVER="https://192.168.16.80:6443"
kubectl config set-cluster kubernetes \
--certificate-authority=/opt/kubernetes/ssl/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials kube-controller-manager \
--client-certificate=./kube-controller-manager.pem \
--client-key=./kube-controller-manager-key.pem \
--embed-certs=true \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
--cluster=kubernetes \
--user=kube-controller-manager \
--kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
3. systemd管理controller-manager
cat > /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
systemctl daemon-reload
systemctl start kube-controller-manager
systemctl enable kube-controller-manager
4.6 部署kube-scheduler
cat > /opt/kubernetes/cfg/kube-scheduler.conf << EOF
KUBE_SCHEDULER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--leader-elect \\
--kubeconfig=/opt/kubernetes/cfg/kube-scheduler.kubeconfig \\
--bind-address=127.0.0.1"
EOF
- --kubeconfig:连接apiserver配置文件
- --leader-elect:当该组件启动多个时,自动选举(HA)
生成kube-scheduler证书:
# 切换工作目录 cd ~/TLS/k8s # 创建证书请求文件 cat > kube-scheduler-csr.json << EOF { "CN": "system:kube-scheduler", "hosts": [], "key": { "algo": "rsa", "size": 2048 }, "names": [ { "C": "CN", "L": "BeiJing", "ST": "BeiJing", "O": "system:masters", "OU": "System" } ] } EOF # 生成证书 cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-scheduler-csr.json | cfssljson -bare kube-scheduler
生成kubeconfig文件(以下是shell命令,直接在终端执行):
KUBE_CONFIG="/opt/kubernetes/cfg/kube-scheduler.kubeconfig"
KUBE_APISERVER="https://192.168.16.80:6443"
kubectl config set-cluster kubernetes \
--certificate-authority=/opt/kubernetes/ssl/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials kube-scheduler \
--client-certificate=./kube-scheduler.pem \
--client-key=./kube-scheduler-key.pem \
--embed-certs=true \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
--cluster=kubernetes \
--user=kube-scheduler \
--kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
cat > /usr/lib/systemd/system/kube-scheduler.service << EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-scheduler.conf
ExecStart=/opt/kubernetes/bin/kube-scheduler \$KUBE_SCHEDULER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
systemctl daemon-reload
systemctl start kube-scheduler
systemctl enable kube-scheduler
生成kubectl连接集群的证书:
cat > admin-csr.json <<EOF
{
"CN": "admin",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing",
"O": "system:masters",
"OU": "System"
}
]
}
EOF
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin
生成kubeconfig文件:
mkdir /root/.kube
KUBE_CONFIG="/root/.kube/config"
KUBE_APISERVER="https://192.168.16.80:6443"
kubectl config set-cluster kubernetes \
--certificate-authority=/opt/kubernetes/ssl/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials cluster-admin \
--client-certificate=/root/TLS/k8s/kube-apiserver/admin.pem \
--client-key=/root/TLS/k8s/kube-apiserver/admin-key.pem \
--embed-certs=true \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
--cluster=kubernetes \
--user=cluster-admin \
--kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
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"} token.csv
如上输出说明Master节点组件运行正常。
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
删除错误签名再重新创建
kubectl delete clusterrolebindings kubelet-bootstrap
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: xyz12366699
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 /root/TLS/k8s/kubernetes/server/bin cp kubelet kube-proxy /opt/kubernetes/bin # 本地拷贝
5.2 部署kubelet
cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-master01 \\
--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
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kubelet初次加入集群引导kubeconfig文件
KUBE_CONFIG="/opt/kubernetes/cfg/bootstrap.kubeconfig" KUBE_APISERVER="https://192.168.16.80:6443" # apiserver IP:PORT TOKEN="bfe8e191df6b2afaf9cc9e83f78b5d50" # 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=${KUBE_APISERVER} \ --kubeconfig=${KUBE_CONFIG} kubectl config set-credentials "kubelet-bootstrap" \ --token=${TOKEN} \ --kubeconfig=${KUBE_CONFIG} kubectl config set-context default \ --cluster=kubernetes \ --user="kubelet-bootstrap" \ --kubeconfig=${KUBE_CONFIG} kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
cat > /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
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
#问题
[root@k8s-master01 server]# kubectl get csr
No resources found
# 批准申请 kubectl certificate approve node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A # 查看节点 kubectl get node NAME STATUS ROLES AGE VERSION k8s-master01 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-proxy
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
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-master01
clusterCIDR: 10.0.0.0/24
EOF
# 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
生成kubeconfig文件:
KUBE_CONFIG="/opt/kubernetes/cfg/kube-proxy.kubeconfig"
KUBE_APISERVER="https://192.168.16.80:6443"
kubectl config set-cluster kubernetes \
--certificate-authority=/opt/kubernetes/ssl/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials kube-proxy \
--client-certificate=./kube-proxy.pem \
--client-key=./kube-proxy-key.pem \
--embed-certs=true \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
--cluster=kubernetes \
--user=kube-proxy \
--kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
cat > /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
systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy
5.5 部署网络组件
Calico是一个纯三层的数据中心网络方案,是目前Kubernetes主流的网络方案。
部署Calico:
[root@k8s-master01 opt]# mkdir calico
[root@k8s-master01 calico]# wget https://docs.projectcalico.org/manifests/calico-etcd.yaml
下载配置文件中所需的镜像:
[root@k8s-master01 calico]# docker pull docker.io/calico/cni:v3.19.1
[root@k8s-master01 calico]# docker pull docker.io/calico/pod2daemon-flexvol:v3.19.1
[root@k8s-master01 calico]# docker pull docker.io/calico/node:v3.19.1
[root@k8s-master01 calico]# docker pull docker.io/calico/kube-controllers:v3.19.1
不提前准备好镜像的话,极有可能导致节点下载镜像失败,最终安装失败,千万不要忽略
Docker私有仓库部署
创建宿主机存储目录,即容器镜像存放路径
mkdir -p /opt/data/registry
下载并启动一个registry容器
[root@k8s-master01 ~]# docker search registry
[root@k8s-master01 DOCKER]# docker pull registry
[root@k8s-master01 DOCKER]# docker run -itd -p 5000:5000 -v /opt/data/registry:/var/lib/registry --name private_registry registry
ab2b50736d5110b5483d7adf5e0e540000788d397bd4c3f3af11bb213b961699
配置http访问
[root@k8s-master01 ~]# cat /etc/docker/daemon.json
{
"registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"],
"insecure-registries": ["192.168.16.80:5000"]
}
重启docker,重启registry服务
[root@k8s-master01 calico]# systemctl restart docker
[root@k8s-master01 calico]# docker restart private_registry
private_registry
[root@k8s-master01 calico]# ps -a
PID TTY TIME CMD
修改tag
docker tag calico/node:v3.19.1 192.168.16.80:5000/calico/node:v3.19.1
docker tag calico/pod2daemon-flexvol:v3.19.1 192.168.16.80:5000/calico/pod2daemon-flexvol:v3.19.1
docker tag calico/cni:v3.19.1 192.168.16.80:5000/calico/cni:v3.19.1
docker tag calico/kube-controllers:v3.19.1 192.168.16.80:5000/calico/kube-controllers:v3.19.1
上传
docker push 192.168.16.80:5000/calico/node:v3.19.1
docker push 192.168.16.80:5000/calico/pod2daemon-flexvol:v3.19.1
docker push 192.168.16.80:5000/calico/cni:v3.19.1
docker push 192.168.16.80:5000/calico/kube-controllers :v3.19.1
查看本地仓库镜像
其它机器拉取192.168.16.80:5000本地镜像
修改docker启动脚本
/usr/lib/systemd/system/docker.service
ExecStart=/usr/bin/dockerd --insecure-registry 192.168.16.80:5000
再重载重启dokcer即可拉取该本地镜像文件
[root@k8s-node01 ~]# systemctl daemon-reload
[root@k8s-node01 ~]# systemctl restart docker
[root@k8s-node01 ~]# docker pull 192.168.16.80:5000/calico/node:v3.19.1
修改配置文件calio-etcd.yaml
① 将配置文件/opt/calico/calico-etcd.yaml中的镜像换成本地镜像地址
② 修改etcd数据库地址以及证书认证
[root@k8s-master01 calico]# mkdir -p /opt/calico/calicoTSL
[root@k8s-master01 calico]# ll
-rw-r--r-- 1 root root 19068 Jun 8 14:29 calico-etcd.yaml
drwxr-xr-x 2 root root 6 Jun 8 17:08 calicoTSL
把/opt/etcd/ssl/中的认证文件拷贝到/opt/calico/calicoTSL
[root@k8s-master01 calicoTSL]# cp /opt/etcd/ssl/ca.pem etcd-ca
[root@k8s-master01 calicoTSL]# cp /opt/etcd/ssl/server-key.pem etcd-key
[root@k8s-master01 calicoTSL]# cp /opt/etcd/ssl/server.pem etcd-cert
③ 修改集群网段
- name: CALICO_IPV4POOL_CIDR
value: "10.0.0.0/24"
(--service-cluster-ip-range=10.0.0.0/24)
④ 配置calico环境变量
env:
# The location of the etcd cluster.
- name: KUBERNETES_SERVICE_HOST
value: "192.168.16.80"
- name: KUBERNETES_SERVICE_PORT
value: "6443"
- name: KUBERNETES_SERVICE_PORT_HTTPS
value: "6443"
kubectl apply -f calico.yaml
kubectl get pods -n kube-system
等Calico Pod都Running,节点也会准备就绪:
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master Ready <none> 37m v1.20.4
5.6 授权apiserver访问kubelet
应用场景:例如kubectl logs
cat > 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 Node
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 [email protected]:/opt/
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service [email protected]:/usr/lib/systemd/system
scp /opt/kubernetes/ssl/ca.pem [email protected]:/opt/kubernetes/ssl
rm -f /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
vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node1
vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-node1
systemctl daemon-reload
systemctl start kubelet kube-proxy
systemctl enable kubelet kube-proxy
5. 在Master上批准新Node kubelet证书申请
# 查看证书请求 kubectl get csr NAME AGE SIGNERNAME REQUESTOR CONDITION node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro 89s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending # 授权请求 kubectl certificate approve node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master01 Ready <none> 47m v1.20.4
k8s-node1 Ready <none> 6m49s v1.20.4
Node2(192.168.31.73 )节点同上。记得修改主机名!
六、部署Dashboard和CoreDNS
6.1 部署Dashboard
kubectl apply -f kubernetes-dashboard.yaml
# 查看部署
kubectl get pods,svc -n kubernetes-dashboard
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。
6.2 部署CoreDNS
CoreDNS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
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。
至此一个单Master集群就搭建完成了!这个环境就足以满足学习实验了,如果你的服务器配置较高,可继续扩容多Master集群!
七、扩容多Master(高可用架构)
Kubernetes作为容器集群系统,通过健康检查+重启策略实现了Pod故障自我修复能力,通过调度算法实现将Pod分布式部署,并保持预期副本数,根据Node失效状态自动在其他Node拉起Pod,实现了应用层的高可用性。
针对Kubernetes集群,高可用性还应包含以下两个层面的考虑:Etcd数据库的高可用性和Kubernetes Master组件的高可用性。 而Etcd我们已经采用3个节点组建集群实现高可用,本节将对Master节点高可用进行说明和实施。
Master节点扮演着总控中心的角色,通过不断与工作节点上的Kubelet和kube-proxy进行通信来维护整个集群的健康工作状态。如果Master节点故障,将无法使用kubectl工具或者API做任何集群管理。
Master节点主要有三个服务kube-apiserver、kube-controller-manager和kube-scheduler,其中kube-controller-manager和kube-scheduler组件自身通过选择机制已经实现了高可用,所以Master高可用主要针对kube-apiserver组件,而该组件是以HTTP API提供服务,因此对他高可用与Web服务器类似,增加负载均衡器对其负载均衡即可,并且可水平扩容。
多Master架构图:
7.1 部署Master2 Node
现在需要再增加一台新服务器,作为Master2 Node,IP是192.168.31.74。
为了节省资源你也可以将之前部署好的Worker Node1复用为Master2 Node角色(即部署Master组件)
Master2 与已部署的Master1所有操作一致。所以我们只需将Master1所有K8s文件拷贝过来,再修改下服务器IP和主机名启动即可。
scp /usr/bin/docker* [email protected]:/usr/bin scp /usr/bin/runc [email protected]:/usr/bin scp /usr/bin/containerd* [email protected]:/usr/bin scp /usr/lib/systemd/system/docker.service [email protected]:/usr/lib/systemd/system scp -r /etc/docker [email protected]:/etc # 在Master2启动Docker systemctl daemon-reload systemctl start docker systemctl enable docker
2. 创建etcd证书目录
在Master2创建etcd证书目录:
mkdir -p /opt/etcd/ssl
拷贝Master1上所有K8s文件和etcd证书到Master2:
scp -r /opt/kubernetes [email protected]:/opt
scp -r /opt/etcd/ssl [email protected]:/opt/etcd
scp /usr/lib/systemd/system/kube* [email protected]:/usr/lib/systemd/system
scp /usr/bin/kubectl [email protected]:/usr/bin
scp -r ~/.kube [email protected]:~
删除kubelet证书和kubeconfig文件:
rm -f /opt/kubernetes/cfg/kubelet.kubeconfig
rm -f /opt/kubernetes/ssl/kubelet*
修改apiserver、kubelet和kube-proxy配置文件为本地IP:
vi /opt/kubernetes/cfg/kube-apiserver.conf
...
--bind-address=192.168.31.74 \
--advertise-address=192.168.31.74 \
...
vi /opt/kubernetes/cfg/kube-controller-manager.kubeconfig
server: https://192.168.31.74:6443
vi /opt/kubernetes/cfg/kube-scheduler.kubeconfig
server: https://192.168.31.74:6443
vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-master2
vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-master2
vi ~/.kube/config
...
server: https://192.168.31.74:6443
6. 启动设置开机启动
systemctl daemon-reload
systemctl start kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxy
systemctl enable kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxy
kubectl get cs
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-1 Healthy {"health":"true"}
etcd-2 Healthy {"health":"true"}
etcd-0 Healthy {"health":"true"}
8. 批准kubelet证书申请
# 查看证书请求 kubectl get csr NAME AGE SIGNERNAME REQUESTOR CONDITION node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU 85m kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending # 授权请求 kubectl certificate approve node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU # 查看Node kubectl get node NAME STATUS ROLES AGE VERSION k8s-master01 Ready <none> 34h v1.20.4 k8s-master2 Ready <none> 2m v1.20.4 k8s-node1 Ready <none> 33h v1.20.4 k8s-node2 Ready <none> 33h v1.20.4
如果你在学习中遇到问题或者文档有误可联系阿良~ 微信: xyz12366699
7.2 部署Nginx+Keepalived高可用负载均衡器
kube-apiserver高可用架构图:
- Nginx是一个主流Web服务和反向代理服务器,这里用四层实现对apiserver实现负载均衡。
- Keepalived是一个主流高可用软件,基于VIP绑定实现服务器双机热备,在上述拓扑中,Keepalived主要根据Nginx运行状态判断是否需要故障转移(漂移VIP),例如当Nginx主节点挂掉,VIP会自动绑定在Nginx备节点,从而保证VIP一直可用,实现Nginx高可用。
注1:为了节省机器,这里与K8s Master节点机器复用。也可以独立于k8s集群之外部署,只要nginx与apiserver能通信就行。
注2:如果你是在公有云上,一般都不支持keepalived,那么你可以直接用它们的负载均衡器产品,直接负载均衡多台Master kube-apiserver,架构与上面一样。
在两台Master节点操作。
1. 安装软件包(主/备)
yum install epel-release -y
yum install nginx keepalived -y
2. Nginx配置文件(主/备一样)
cat > /etc/nginx/nginx.conf << "EOF" user nginx; worker_processes auto; error_log /var/log/nginx/error.log; pid /run/nginx.pid; include /usr/share/nginx/modules/*.conf; events { worker_connections 1024; } # 四层负载均衡,为两台Master apiserver组件提供负载均衡 stream { log_format main '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent'; access_log /var/log/nginx/k8s-access.log main; upstream k8s-apiserver { server 192.168.31.71:6443; # Master1 APISERVER IP:PORT server 192.168.31.74:6443; # Master2 APISERVER IP:PORT } server { listen 16443; # 由于nginx与master节点复用,这个监听端口不能是6443,否则会冲突 proxy_pass k8s-apiserver; } } http { log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"'; access_log /var/log/nginx/access.log main; sendfile on; tcp_nopush on; tcp_nodelay on; keepalive_timeout 65; types_hash_max_size 2048; include /etc/nginx/mime.types; default_type application/octet-stream; server { listen 80 default_server; server_name _; location / { } } } EOF
3. keepalived配置文件(Nginx Master)
cat > /etc/keepalived/keepalived.conf << EOF global_defs { notification_email { [email protected] [email protected] [email protected] } notification_email_from [email protected] smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id NGINX_MASTER } vrrp_script check_nginx { script "/etc/keepalived/check_nginx.sh" } vrrp_instance VI_1 { state MASTER interface ens33 # 修改为实际网卡名 virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的 priority 100 # 优先级,备服务器设置 90 advert_int 1 # 指定VRRP 心跳包通告间隔时间,默认1秒 authentication { auth_type PASS auth_pass 1111 } # 虚拟IP virtual_ipaddress { 192.168.31.88/24 } track_script { check_nginx } } EOF
- vrrp_script:指定检查nginx工作状态脚本(根据nginx状态判断是否故障转移)
- virtual_ipaddress:虚拟IP(VIP)
准备上述配置文件中检查nginx运行状态的脚本:
cat > /etc/keepalived/check_nginx.sh << "EOF"
#!/bin/bash
count=$(ss -antp |grep 16443 |egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
exit 1
else
exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh
4. keepalived配置文件(Nginx Backup)
cat > /etc/keepalived/keepalived.conf << EOF global_defs { notification_email { [email protected] [email protected] [email protected] } notification_email_from [email protected] smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id NGINX_BACKUP } vrrp_script check_nginx { script "/etc/keepalived/check_nginx.sh" } vrrp_instance VI_1 { state BACKUP interface ens33 virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的 priority 90 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.31.88/24 } track_script { check_nginx } } EOF
准备上述配置文件中检查nginx运行状态的脚本:
cat > /etc/keepalived/check_nginx.sh << "EOF"
#!/bin/bash
count=$(ss -antp |grep 16443 |egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
exit 1
else
exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh
注:keepalived根据脚本返回状态码(0为工作正常,非0不正常)判断是否故障转移。
systemctl daemon-reload
systemctl start nginx keepalived
systemctl enable nginx keepalived
ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 00:0c:29:04:f7:2c brd ff:ff:ff:ff:ff:ff
inet 192.168.31.80/24 brd 192.168.31.255 scope global noprefixroute ens33
valid_lft forever preferred_lft forever
inet 192.168.31.88/24 scope global secondary ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe04:f72c/64 scope link
valid_lft forever preferred_lft forever
可以看到,在ens33网卡绑定了192.168.31.88 虚拟IP,说明工作正常。
7. Nginx+Keepalived高可用测试
关闭主节点Nginx,测试VIP是否漂移到备节点服务器。
在Nginx Master执行 pkill nginx;
在Nginx Backup,ip addr命令查看已成功绑定VIP。
找K8s集群中任意一个节点,使用curl查看K8s版本测试,使用VIP访问:
curl -k https://192.168.31.88:16443/version
{
"major": "1",
"minor": "20",
"gitVersion": "v1.20.4",
"gitCommit": "e87da0bd6e03ec3fea7933c4b5263d151aafd07c",
"gitTreeState": "clean",
"buildDate": "2021-02-18T16:03:00Z",
"goVersion": "go1.15.8",
"compiler": "gc",
"platform": "linux/amd64"
}
可以正确获取到K8s版本信息,说明负载均衡器搭建正常。该请求数据流程:curl -> vip(nginx) -> apiserver
通过查看Nginx日志也可以看到转发apiserver IP:
tail /var/log/nginx/k8s-access.log -f
192.168.31.71 192.168.31.71:6443 - [02/Apr/2021:19:17:57 +0800] 200 423
192.168.31.71 192.168.31.72:6443 - [02/Apr/2021:19:18:50 +0800] 200 423
到此还没结束,还有下面最关键的一步。
7.3 修改所有Worker Node连接LB VIP
试想下,虽然我们增加了Master2 Node和负载均衡器,但是我们是从单Master架构扩容的,也就是说目前所有的Worker Node组件连接都还是Master1 Node,如果不改为连接VIP走负载均衡器,那么Master还是单点故障。
因此接下来就是要改所有Worker Node(kubectl get node命令查看到的节点)组件配置文件,由原来192.168.31.71修改为192.168.31.88(VIP)。
在所有Worker Node执行:
sed -i 's#192.168.31.71:6443#192.168.31.88:16443#' /opt/kubernetes/cfg/*
systemctl restart kubelet kube-proxy
检查节点状态:
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master01 Ready <none> 32d v1.20.4
k8s-master2 Ready <none> 10m v1.20.4
k8s-node1 Ready <none> 31d v1.20.4
k8s-node2 Ready <none> 31d v1.20.4
至此,一套完整的 Kubernetes 高可用集群就部署完成了!