作者:运维人在路上
个人博客:https://www.cnblogs.com/hujinzhong
微信公众号:运维人在路上
Bilibili账号:https://space.bilibili.com/409609392
个人简介:本人是一枚大型电商平台的运维工程师,对开发及运维有一定了解,现分享技术干货,欢迎大家交流!
1)方式一:kubeadm
部署
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。
2)方式二:二进制软件包
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
3)两种方式对比
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)建议最小硬件配置:2核CPU、2G内存、30G硬盘
2)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 | 版本 |
---|---|
操作系统 | CentOS7.x_x64 (mini) |
容器引擎 | Docker CE 19 |
Kubernetes | Kubernetes v1.20 |
角色 | IP | 组件 |
---|---|---|
k8s-master1 | 10.0.0.71 | kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker,etcd,nginx,keepalived |
k8s-master2 | 10.0.0.74 | kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker,nginx,keepalived |
k8s-node1 | 10.0.0.72 | kubelet,kube-proxy,docker,etcd |
k8s-node2 | 10.0.0.73 | kubelet,kube-proxy,docker,etcd |
负载均衡器IP | 10.0.0.88 (VIP) |
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)
单Master架构图:
单Master服务器规划:
角色 | IP | 组件 |
---|---|---|
k8s-master | 10.0.0.71 | kube-apiserver,kube-controller-manager,kube-scheduler,etcd |
k8s-node1 | 10.0.0.72 | kubelet,kube-proxy,docker,etcd |
k8s-node2 | 10.0.0.73 | kubelet,kube-proxy,docker,etcd |
# 1、关闭防火墙
systemctl stop firewalld
systemctl disable firewalld
# 2、关闭selinux
sed -i ‘s/enforcing/disabled/‘ /etc/selinux/config # 永久
setenforce 0 # 临时
# 3、关闭swap
swapoff -a # 临时
sed -ri ‘s/.*swap.*/#&/‘ /etc/fstab # 永久
# 4、根据规划设置主机名
hostnamectl set-hostname <hostname>
# 5、在master添加hosts
cat >> /etc/hosts << EOF
10.0.0.71 k8s-master01
10.0.0.74 k8s-master02
10.0.0.72 k8s-node01
10.0.0.73 k8s-node02
EOF
# 6、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
# 7、时间同步
yum install ntpdate -y
ntpdate time.windows.com
k8s集群需要用到很多证书,先将证书做一个简单的说明:
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 | 10.0.0.71 |
etcd-2 | 10.0.0.72 |
etcd-3 | 10.0.0.73 |
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
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
# 下载软件包
mkdir cfssl && cd 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/bin/cfssl-certinfo
# 1、创建工作目录
mkdir -p ~/TLS/{etcd,k8s} && cd ~/TLS/etcd
# 2、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
# 3、生成证书:会生成ca.pem和ca-key.pem文件
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
# 创建证书请求文件
cat > server-csr.json << EOF
{
"CN": "etcd",
"hosts": [
"10.0.0.71",
"10.0.0.72",
"10.0.0.73"
],
"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,会生成server.pem和server-key.pem文件
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server
1)下载etcd二进制文件
地址:https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz
2)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/
3)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://10.0.0.71:2380"
ETCD_LISTEN_CLIENT_URLS="https://10.0.0.71:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://10.0.0.71:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://10.0.0.71:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://10.0.0.71:2380,etcd-2=https://10.0.0.72:2380,etcd-3=https://10.0.0.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF
配置文件说明:
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
4)systemd管理etcd
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
5)拷贝生成的证书至指定位置
# 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/
6)启动并设置开机启动
systemctl daemon-reload
systemctl start etcd
systemctl enable etcd
注意:此时启动一台etcd会显示hang住,这是因为其他两个节点并没有启动,可以查看日志/var/log/messages
7)将上面节点1所有生成的文件拷贝到节点2和节点3
scp -r /opt/etcd/ root@10.0.0.72:/opt/
scp /usr/lib/systemd/system/etcd.service root@10.0.0.72:/usr/lib/systemd/system/
scp -r /opt/etcd/ root@10.0.0.73:/opt/
scp /usr/lib/systemd/system/etcd.service root@10.0.0.73:/usr/lib/systemd/system/
8)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
vim /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://10.0.0.71:2380" # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://10.0.0.71:2379" # 修改此处为当前服务器IP
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://10.0.0.71:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://10.0.0.71:2379" # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://10.0.0.71:2380,etcd-2=https://10.0.0.72:2380,etcd-3=https://10.0.0.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
9)启动etcd并设置开机启动
systemctl daemon-reload
systemctl start etcd
systemctl enable etcd
10)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://10.0.0.71:2379,https://10.0.0.72:2379,https://10.0.0.73:2379" endpoint health --write-out=table
# 显示结果如下,说明部署成功
+------------------------+--------+-------------+-------+
| ENDPOINT | HEALTH | TOOK | ERROR |
+------------------------+--------+-------------+-------+
| https://10.0.0.72:2379 | true | 15.05078ms | |
| https://10.0.0.71:2379 | true | 15.120261ms | |
| https://10.0.0.73:2379 | true | 17.14033ms | |
+------------------------+--------+-------------+-------+
如果有问题第一步先看日志:/var/log/message
或 journalctl -u etcd
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。
1)解压二进制软件包
tar zxvf docker-19.03.9.tgz
mv docker/* /usr/bin
docker version
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)创建配置文件
mkdir /etc/docker
cat > /etc/docker/daemon.json << EOF
{
"registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF
4)启动并设置开机启动
systemctl daemon-reload
systemctl start docker
systemctl enable docker
cd ~/TLS/k8s
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:生成ca.pem和ca-key.pem文件
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
# 创建证书请求文件
cat > server-csr.json << EOF
{
"CN": "kubernetes",
"hosts": [
"10.0.0.1",
"127.0.0.1",
"10.0.0.71",
"10.0.0.72",
"10.0.0.73",
"10.0.0.74",
"10.0.0.88",
"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
注意: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,生成server.pem和server-key.pem
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare server
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
1)下载并解压二进制软件包
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/
2)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://10.0.0.71:2379,https://10.0.0.72:2379,https://10.0.0.73:2379 \--bind-address=10.0.0.71 \--secure-port=6443 \--advertise-address=10.0.0.71 \--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 \--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
参数说明:
--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
3)拷贝生成的证书
# 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/
4)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:
5)创建token文件
# 格式:token,用户名,UID,用户组
cat > /opt/kubernetes/cfg/token.csv << EOF
c47ffb939f5ca36231d9e3121a252940,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF
token也可自行生成替换:
head -c 16 /dev/urandom | od -An -t x | tr -d ‘ ‘
6)systemd管理apiserver
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
7)启动并设置开机启动
systemctl daemon-reload
systemctl start kube-apiserver
systemctl enable kube-apiserver
1)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 \--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
配置说明:
--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
2)生成kubeconfig文件
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://10.0.0.71:6443"
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
4)启动并设置开机启动
systemctl daemon-reload
systemctl start kube-controller-manager
systemctl enable kube-controller-manager
1)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 \--kubeconfig=/opt/kubernetes/cfg/kube-scheduler.kubeconfig \--bind-address=127.0.0.1"
EOF
参数说明:
--kubeconfig:连接apiserver配置文件
--leader-elect:当该组件启动多个时,自动选举(HA)
2)生成kubeconfig文件
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://10.0.0.71:6443"
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=${KUBE_CONFIG}
3)systemd管理scheduler
cat > /usr/lib/systemd/system/kube-scheduler.service << EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-scheduler.conf
ExecStart=/opt/kubernetes/bin/kube-scheduler \$KUBE_SCHEDULER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
4)启动并设置开机启动
systemctl daemon-reload
systemctl start kube-scheduler
systemctl enable kube-scheduler
5)查看集群状态
生成kubectl连接集群的证书:
cat > admin-csr.json <<EOF
{
"CN": "admin",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing",
"O": "system:masters",
"OU": "System"
}
]
}
EOF
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin
生成kubeconfig文件:
mkdir /root/.kube
KUBE_CONFIG="/root/.kube/config"
KUBE_APISERVER="https://10.0.0.71:6443"
kubectl config set-cluster kubernetes --certificate-authority=/opt/kubernetes/ssl/ca.pem --embed-certs=true --server=${KUBE_APISERVER} --kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials cluster-admin --client-certificate=./admin.pem --client-key=./admin-key.pem --embed-certs=true --kubeconfig=${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
# 如下输出说明Master节点组件运行正常
Warning: v1 ComponentStatus is deprecated in v1.19+
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"}
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
下面还是在Master Node上操作,即同时作为Worker Node
# 在所有worker node创建工作目录(master已创建,新加入节点需要创建)
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}
# 从解压的k8s server压缩包中拷贝文件
cd /root/soft/kubernetes/server/bin
cp kubelet kube-proxy /opt/kubernetes/bin
1)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-master1 \--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
参数说明:
--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kubelet初次加入集群引导kubeconfig文件
KUBE_CONFIG="/opt/kubernetes/cfg/bootstrap.kubeconfig"
KUBE_APISERVER="https://10.0.0.71:6443" # 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=${KUBE_APISERVER} --kubeconfig=${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}
4)systemd管理kubelet
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
5)启动并设置开机启动
systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet
6)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-jaqXhwxFBnD-1ui9omPdF__0SGovk2ZRhszz_QMGJxI 62s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
# 批准申请
kubectl certificate approve node-csr-jaqXhwxFBnD-1ui9omPdF__0SGovk2ZRhszz_QMGJxI
# 查看节点(由于网络插件还没有部署,节点会没有准备就绪 NotReady)
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 NotReady <none> 7s v1.20.4
1)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-master1
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
生成kubeconfig文件:
KUBE_CONFIG="/opt/kubernetes/cfg/kube-proxy.kubeconfig"
KUBE_APISERVER="https://10.0.0.71:6443"
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}
4)systemd管理kube-proxy
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
5)启动并设置开机启动
systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy
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。
下载地址:https://docs.projectcalico.org/
# 部署Calico
kubectl apply -f calico.yaml
kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
calico-kube-controllers-97769f7c7-q9thh 1/1 Running 0 2m12s
calico-node-pjxtr 1/1 Running 0 2m12s
# 等Calico Pod都Running,节点也会准备就绪
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready <none> 18m v1.20.4
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
1)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10.0.0.72/73
scp -r /opt/kubernetes root@10.0.0.72:/opt/
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@10.0.0.72:/usr/lib/systemd/system
scp /opt/kubernetes/ssl/ca.pem root@10.0.0.72:/opt/kubernetes/ssl
2)删除kubelet证书和kubeconfig文件
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
rm -f /opt/kubernetes/cfg/kubelet.kubeconfig
rm -f /opt/kubernetes/ssl/kubelet*
3)修改配置文件中的主机名
vim /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node1
vim /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 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-E0cAzR_Tv7S1l6eThCsx5IeVG20AYSeTLOrgW5mAZFA 70s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
# 同意授权请求
kubectl certificate approve node-csr-E0cAzR_Tv7S1l6eThCsx5IeVG20AYSeTLOrgW5mAZFA
6)查看Node状态
kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready <none> 31m v1.20.4
k8s-node01 Ready <none> 111s v1.20.4
Node2(10.0.0.73 )节点同上。记得修改主机名!
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:
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!
原文:https://www.cnblogs.com/hujinzhong/p/14648961.html