####1.1 环境准备
服务器要求
• 建议最小硬件配置:2核CPU、2G内存、30G硬盘
软件环境
软件 | 版本 |
---|---|
操作系统 | CentOS7.x_x64 |
容器引擎 | Docker CE 19 |
Kubernetes | Kubernetes v1.20 |
服务器整体规划
角色 | IP | 组件 |
---|---|---|
k8s-matser1 | 172.21.51.71 | kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker,etcd,nginx,keepalived |
k8s-master2 | 172.21.51.74 | kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-porxy,docker,nginx,Keepalived |
k8s-node1 | 172.21.51.72 | kubelet,kubeproxy,docker,etcd |
k8s-node2 | 172.31.51.73 | kubelet,kube-porxy,docker,etcd |
负载均衡器 | 172.21.51.88(VIP) | |
也可以将etcd集群和负载均衡单独分离出来 |
单master架构图
单master服务器规划
角色 | IP | 组件 |
---|---|---|
k8s-master | 172.21.51.71 | kube-apiserver,kube-controller-manager,kube-scheduler,etcd,docker |
k8s-node1 | 172.21.51.72 | kubelet,kube-proxy,docker,etcd |
k8s-node2 | 172.21.51.73 | kubelet,kube-proxy,docker,etcd |
# 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
172.21.51.71 k8s-master1
172.21.51.72 k8s-node1
172.21.51.73 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
# 配置yum源
cd /etc/yum.repos.d/ && mkdir backup_$(date +%F)
mv ./*.repo backup_
wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
yum makecache && cd
# 安装常用
yum install -y ntpdate vim wget tree httpd-tools lrzsz net-tools bridge-utils unzip telnet
# 时间同步
ntpdate time.windows.com
# 关闭 networkmanager服务
systemctl enable NetworkManager
systemctl stop NetworkManager
###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,可容忍机器故障数量等于总数除以二减去一。
节点名称 | IP |
---|---|
etcd-1 | 172.21.51.71 |
etcd-2 | 172.21.51.72 |
etcd-3 | 172.21.51.73 |
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。
在任意一台服务操作,这里了使用master节点部署。
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
# 准备目录
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 -
# 如下:会生成ca.pem 和 ca-key.pem文件
[root@k8s-master1 etcd]# ll
total 8
-rw-r--r--. 1 root root 287 Aug 14 14:12 ca-config.json
-rw-r--r--. 1 root root 209 Aug 14 14:13 ca-csr.json
[root@k8s-master1 etcd]# cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
2021/08/14 14:13:17 [INFO] generating a new CA key and certificate from CSR
2021/08/14 14:13:17 [INFO] generate received request
2021/08/14 14:13:17 [INFO] received CSR
2021/08/14 14:13:17 [INFO] generating key: rsa-2048
2021/08/14 14:13:17 [INFO] encoded CSR
2021/08/14 14:13:17 [INFO] signed certificate with serial number 13042066667921354585937734212236512385297354843
[root@k8s-master1 etcd]# ls
ca-config.json ca.csr ca-csr.json ca-key.pem ca.pem
创建证书申请文件
cat > server-csr.json << EOF
{
"CN": "etcd",
"hosts": [
"172.21.51.71",
"172.21.51.72",
"172.21.51.73",
"172.21.51.81",
"172.21.51.82",
"172.21.51.83"
],
"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,只能多,不能少,为了方便后期扩容,可以多写几个预留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
# 提示如下:会生成server.pem和server-key.pem文件
[root@k8s-master1 etcd]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server
2021/08/14 14:31:33 [INFO] generate received request
2021/08/14 14:31:33 [INFO] received CSR
2021/08/14 14:31:33 [INFO] generating key: rsa-2048
2021/08/14 14:31:33 [INFO] encoded CSR
2021/08/14 14:31:33 [INFO] signed certificate with serial number 463187719751335716138642349093857998280805876080
2021/08/14 14:31:33 [WARNING] This certificate lacks a "hosts" field. This makes it unsuitable for
websites. For more information see the Baseline Requirements for the Issuance and Management
of Publicly-Trusted Certificates, v.1.1.6, from the CA/Browser Forum (https://cabforum.org);
specifically, section 10.2.3 ("Information Requirements").
[root@k8s-master1 etcd]# echo $?
0
[root@k8s-master1 etcd]# ls
ca-config.json ca.csr ca-csr.json ca-key.pem ca.pem server.csr server-csr.json server-key.pem server.pem
下载地址:https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz
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
cd /opt/
mkdir -p /opt/etcd/{bin,cfg,ssl} -p
wget https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz
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://172.21.51.71:2380"
ETCD_LISTEN_CLIENT_URLS="https://172.21.51.71:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.21.51.71:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://172.21.51.71:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://172.21.51.71:2380,etcd-2=https://172.21.51.72:2380,etcd-3=https://172.21.51.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF
参数解释:
ETCD_NAME= 节点名称,集群中必须唯一
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= 集群通过地址
ETCD_ADVERTISE_CLIENT_URLS= 客户端通过地址
ETCD_INITIAL_CLUSTER= 集群各节点地址
ETCD_INITIAL_CLUSTER_TOKEN= 集群token
ETCD_INITIAL_CLUSTER_STATE= 加入集群的当前状态,new 是新机器,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
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/
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-2" # 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://172.21.51.72:2380" # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://172.21.51.72:2379" # 修改此处为当前服务器IP
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.21.51.72:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://172.21.51.72:2379" # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://172.21.51.71:2380,etcd-2=https://172.21.51.72:2380,etcd-3=https://172.21.51.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
systemctl daemon-reload
systemctl start etcd
systemctl enable etcd
systemctl status etcd
查看启动日志
journalctl -fu etcd
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://172.21.51.71:2379,https://172.21.51.72:2379,https://172.21.51.73:2379" endpoint health --write-out=table
[root@k8s-master1 ~]# ETCDCTL=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://172.21.51.71:2379,https://172.21.51.72:2379,https://172.21.51.73:2379" endpoint health --write-out=table
+---------------------------+--------+-------------+-------+
| ENDPOINT | HEALTH | TOOK | ERROR |
+---------------------------+--------+-------------+-------+
| https://172.21.51.71:2379 | true | 8.964636ms | |
| https://172.21.51.72:2379 | true | 10.973473ms | |
| https://172.21.51.73:2379 | true | 11.852294ms | |
+---------------------------+--------+-------------+-------+
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
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。
wget https://download.docker.com/linux/static/stable/x86_64/docker-19.03.9.tgz
tar zxvf docker-19.03.9.tgz
mv docker/* /usr/bin
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
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
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
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
[root@k8s-master1 k8s]# cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
2021/08/14 23:48:47 [INFO] generating a new CA key and certificate from CSR
2021/08/14 23:48:47 [INFO] generate received request
2021/08/14 23:48:47 [INFO] received CSR
2021/08/14 23:48:47 [INFO] generating key: rsa-2048
2021/08/14 23:48:47 [INFO] encoded CSR
2021/08/14 23:48:47 [INFO] signed certificate with serial number 429434885767963696370191351654043895485854229933
会生成ca.pem 和ca-key.pem 文件
[root@k8s-master1 k8s]# ls
ca-config.json ca.csr ca-csr.json ca-key.pem ca.pem
创建证书申请文件
cat > server-csr.json << EOF
{
"CN": "kubernetes",
"hosts": [
"10.0.0.1",
"127.0.0.1",
"172.21.51.71",
"172.21.51.72",
"172.21.51.73",
"172.21.51.74",
"172.21.51.81",
"172.21.51.82",
"172.21.51.83",
"172.21.51.84",
"172.21.51.85",
"172.21.51.88",
"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
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。
wget https://dl.k8s.io/v1.20.9/kubernetes-server-linux-amd64.tar.gz
####4.3 解压二进制包
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}
tar xzf 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://172.21.51.71:2379,https://172.21.51.72:2379,https://172.21.51.73:2379 \\
--bind-address=172.21.51.71 \\
--secure-port=6443 \\
--advertise-address=172.21.51.71 \\
--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:上面两个反斜杠 \ \ 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,0-8
• --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
更多参数参考官网:https://kubernetes.io/docs/reference/command-line-tools-reference/kube-apiserver/
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/
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。
创建上述配置文件中token文件
#
[root@k8s-master1 ~]# head -c 16 /dev/urandom | od -An -t x | tr -d ' '
b3b4dba5e64a204dc03479e03ecf1588
cat > /opt/kubernetes/cfg/token.csv << EOF
b3b4dba5e64a204dc03479e03ecf1588,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF
格式:token,用户名,UID,用户组
token 也可以自行生成替换:
head -c 16 /dev/urandom | od -An -t x | tr -d ' '
命令注释:
head 显示文件的开头部分
-c, --bytes=[-]NUM 显示前NUM字节;如果NUM前有"-",那么会打印除了文件末尾的NUM字节以外的其他内容。
od 输出文件的八进制、十六进制等格式编码的字节
-A:<字码基数>:选择以何种基数计算字码;
-t<输出格式>或--format=<输出格式>:设置输出格式;
tr
将字符进行替换压缩和删除
-d或——delete:删除所有属于第一字符集的字符;
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
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
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://172.21.51.71:6443"
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}
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
生成证书文件
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
KUBE_CONFIG="/opt/kubernetes/cfg/kube-scheduler.kubeconfig"
KUBE_APISERVER="https://172.21.51.71:6443"
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=${KUBE_CONFIG}
cat > /usr/lib/systemd/system/kube-scheduler.service << EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-scheduler.conf
ExecStart=/opt/kubernetes/bin/kube-scheduler \$KUBE_SCHEDULER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
systemctl daemon-reload
systemctl start kube-scheduler
systemctl enable kube-scheduler
生成kubectl连接集群的证书
cat > admin-csr.json <
生成kubeconfig文件
mkdir /root/.kube
KUBE_CONFIG="/root/.kube/config"
KUBE_APISERVER="https://172.21.51.71:6443"
kubectl config set-cluster kubernetes \
--certificate-authority=/opt/kubernetes/ssl/ca.pem \
--embed-certs=true \
--server=${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
[root@k8s-master1 k8s]# kubectl get cs
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"}
如上输出说明master节点组件运行正常。
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,主从复用
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
从master节点拷贝:
cd /root/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-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
• --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
KUBE_CONFIG="/opt/kubernetes/cfg/bootstrap.kubeconfig"
KUBE_APISERVER="https://172.21.51.71:6443" # apiserver IP:PORT
TOKEN="b3b4dba5e64a204dc03479e03ecf1588" # 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
查看kubelet证书请求
[root@k8s-master1 bin]# kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-CwXx8GWIrGkN6OQeNyA9O08dYQWremUrLYJjH9bKa6k 45s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
# 批准申请
kubectl certificate approve node-csr-CwXx8GWIrGkN6OQeNyA9O08dYQWremUrLYJjH9bKa6k
# 查看节点
[root@k8s-master1 bin]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 NotReady 13s v1.20.9
由于网络插件还没部署,所有节点没有准备就绪,NotReady
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-master1
clusterCIDR: 10.244.0.0/16
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://172.21.51.71:6443"
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}
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
calico是一个纯三层的数据中心网络方案,是目前kubernetes主流网络方案
部署calico
mkdir -p /home/yaml
cd /home/yaml
wget https://docs.projectcalico.org/manifests/calico.yaml
#修改YAML:
#下载完后还需要修改里面定义Pod网络(CALICO_IPV4POOL_CIDR),与前面kube-controller-manager配置文件指定的cluster-cidr网段一样10.244.0.0/16
sed -i "3685,3686s/# //" calico.yaml
sed -i "3686s#192.168.0.0/16#10.244.0.0/16#" calico.yaml
# 网络插件下载地址
wget https://github.com/containernetworking/plugins/releases/download/v1.0.0/cni-plugins-linux-amd64-v1.0.0.tgz
kubectl apply -f calico.yaml
kubectl get pods -n kube-system
等Calico Pod都Running,节点也会准备就绪:
[root@k8s-master1 yaml]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready 80m v1.20.9
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
在Master节点将Worker Node涉及文件拷贝到新节点172.21.51.72/73
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
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
vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node2
vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-node2
systemctl daemon-reload
systemctl start kubelet kube-proxy
systemctl enable kubelet kube-proxy
systemctl status kube-proxy
# 查看证书请求
[root@k8s-master1 yaml]# kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-7_86FVcMARHpAsrJ-yWWBXyOpg4R-RkgXVkygl3nK_Q 63s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
node-csr-CwXx8GWIrGkN6OQeNyA9O08dYQWremUrLYJjH9bKa6k 94m kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Approved,Issued
node-csr-xVyN-IRcm9QKYLaIBjFx0eZGqAtgstWvAZuanLTUbVo 62s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
# 授权请求
kubectl certificate approve node-csr-7_86FVcMARHpAsrJ-yWWBXyOpg4R-RkgXVkygl3nK_Q
kubectl certificate approve node-csr-xVyN-IRcm9QKYLaIBjFx0eZGqAtgstWvAZuanLTUbVo
# 这里不小心把node2当成node1 加入了,master端有批准了,导致node无法加入,后面在etcd中删除对应的证书申请,重新加入恢复正常,Linux一切皆是文件
[root@k8s-master1 ~]# kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-7_86FVcMARHpAsrJ-yWWBXyOpg4R-RkgXVkygl3nK_Q 42m kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Approved,Issued
node-csr-CwXx8GWIrGkN6OQeNyA9O08dYQWremUrLYJjH9bKa6k 136m kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Approved,Issued
node-csr-Dc73TLG03NpqmGYfXSCCNORzMHKUvhyFLYzobPTfVMM 7s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
kubectl certificate approve node-csr-Dc73TLG03NpqmGYfXSCCNORzMHKUvhyFLYzobPTfVMM
[root@k8s-master1 ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready 138m v1.20.9
k8s-node1 Ready 43m v1.20.9
k8s-node2 Ready 17s v1.20.9
wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta8/aio/deploy/recommended.yaml
[root@k8s-master1 ~]# cd /home/yaml/
[root@k8s-master1 yaml]# ls
apiserver-to-kubelet-rbac.yaml calico.yaml
[root@k8s-master1 yaml]# vim 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:
# 修改Service为NodePort类型,文件的45行上下
......
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kubernetes-dashboard
spec:
ports:
- port: 443
targetPort: 8443
selector:
k8s-app: kubernetes-dashboard
type: NodePort # 加上type=NodePort变成NodePort类型的服务
---
...
kubectl apply -f recommended.yaml
[root@k8s-master1 yaml]# kubectl get pods,svc -n kubernetes-dashboard
NAME READY STATUS RESTARTS AGE
pod/dashboard-metrics-scraper-7445d59dfd-kf4fr 1/1 Running 0 46s
pod/kubernetes-dashboard-7d8466d688-7cknh 1/1 Running 0 46s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/dashboard-metrics-scraper ClusterIP 10.0.0.238 8000/TCP 46s
service/kubernetes-dashboard NodePort 10.0.0.184 443:30026/TCP 46s
访问地址:https://NodeIP:30026 https://172.21.51.71:30026/
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}')
root@k8s-master1 yaml]# kubectl create serviceaccount dashboard-admin -n kube-system
serviceaccount/dashboard-admin created
[root@k8s-master1 yaml]# kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
clusterrolebinding.rbac.authorization.k8s.io/dashboard-admin created
[root@k8s-master1 yaml]# kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')
Name: dashboard-admin-token-9nrwn
Namespace: kube-system
Labels:
Annotations: kubernetes.io/service-account.name: dashboard-admin
kubernetes.io/service-account.uid: f58b4bfb-171b-4ccd-8714-7fa6bbe4f05a
Type: kubernetes.io/service-account-token
Data
====
ca.crt: 1359 bytes
namespace: 11 bytes
token: eyJhbGciOiJSUzI1NiIsImtpZCI6InMwWC0tYzVybnRCM3hDLW9GMGtlZk50LWRPZWV5RFNDbm5LTHBWUVhXUlEifQ.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.bRTyoT_F9LKpX5U9d0iDM6Jtw7IBDptGMnxST7UYlQ5F8oQ8CeHORTzrmFZQ_1qVzWj6SjvUfXv_mPvIrnPTTvhYiS9-xxeIQCeCV5r4Sx2gqFkFxNipOt995trKxBZ4JtQQ8bPdKedXur5LYUg1SEtZsx8bNCPFNDpcYjh7NwH02xs9Sxs6OUUjNDswumk2JleAAwiIqxpCcFhflz5Xsbo6fCtqwnzWapIv84PAoDQYXOPBCIavvu8M7VA76UHQoX5ZgSnpUZw-A3TmeFKjEiuoRl_5ZN_LZ-zAReJ4ws0OiSDlh2tOxqZViPTaKOIltdEyrJCeoZhkrZLIKpJnpw
[root@k8s-master1 yaml]#
coreDNS用于集群内部service名称解析
apiVersion: v1
kind: ServiceAccount
metadata:
name: coredns
namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
labels:
kubernetes.io/bootstrapping: rbac-defaults
name: system:coredns
rules:
- apiGroups:
- ""
resources:
- endpoints
- services
- pods
- namespaces
verbs:
- list
- watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
annotations:
rbac.authorization.kubernetes.io/autoupdate: "true"
labels:
kubernetes.io/bootstrapping: rbac-defaults
name: system:coredns
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: system:coredns
subjects:
- kind: ServiceAccount
name: coredns
namespace: kube-system
---
apiVersion: v1
kind: ConfigMap
metadata:
name: coredns
namespace: kube-system
data:
Corefile: |
.:53 {
errors
health {
lameduck 5s
}
ready
kubernetes cluster.local in-addr.arpa ip6.arpa {
fallthrough in-addr.arpa ip6.arpa
}
prometheus :9153
forward . /etc/resolv.conf {
max_concurrent 1000
}
cache 30
loop
reload
loadbalance
}
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: coredns
namespace: kube-system
labels:
k8s-app: kube-dns
kubernetes.io/name: "CoreDNS"
spec:
# replicas: not specified here:
# 1. Default is 1.
# 2. Will be tuned in real time if DNS horizontal auto-scaling is turned on.
strategy:
type: RollingUpdate
rollingUpdate:
maxUnavailable: 1
selector:
matchLabels:
k8s-app: kube-dns
template:
metadata:
labels:
k8s-app: kube-dns
spec:
priorityClassName: system-cluster-critical
serviceAccountName: coredns
tolerations:
- key: "CriticalAddonsOnly"
operator: "Exists"
nodeSelector:
kubernetes.io/os: linux
affinity:
podAntiAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 100
podAffinityTerm:
labelSelector:
matchExpressions:
- key: k8s-app
operator: In
values: ["kube-dns"]
topologyKey: kubernetes.io/hostname
containers:
- name: coredns
image: coredns/coredns:1.8.0
imagePullPolicy: IfNotPresent
resources:
limits:
memory: 170Mi
requests:
cpu: 100m
memory: 70Mi
args: [ "-conf", "/etc/coredns/Corefile" ]
volumeMounts:
- name: config-volume
mountPath: /etc/coredns
readOnly: true
ports:
- containerPort: 53
name: dns
protocol: UDP
- containerPort: 53
name: dns-tcp
protocol: TCP
- containerPort: 9153
name: metrics
protocol: TCP
securityContext:
allowPrivilegeEscalation: false
capabilities:
add:
- NET_BIND_SERVICE
drop:
- all
readOnlyRootFilesystem: true
livenessProbe:
httpGet:
path: /health
port: 8080
scheme: HTTP
initialDelaySeconds: 60
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 5
readinessProbe:
httpGet:
path: /ready
port: 8181
scheme: HTTP
dnsPolicy: Default
volumes:
- name: config-volume
configMap:
name: coredns
items:
- key: Corefile
path: Corefile
---
apiVersion: v1
kind: Service
metadata:
name: kube-dns
namespace: kube-system
annotations:
prometheus.io/port: "9153"
prometheus.io/scrape: "true"
labels:
k8s-app: kube-dns
kubernetes.io/cluster-service: "true"
kubernetes.io/name: "CoreDNS"
spec:
selector:
k8s-app: kube-dns
clusterIP: 10.0.0.2
ports:
- name: dns
port: 53
protocol: UDP
- name: dns-tcp
port: 53
protocol: TCP
- name: metrics
port: 9153
protocol: TCP
kubectl apply -f coredns.yaml
kubectl get pods -n kube-system
docker pull coredns/coredns:1.8.0
[root@k8s-master1 yaml]# 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
kubernetes作为容器集群系统,通过监控检查+重启策略实现了pod故障自我修复能力,听过调度算法实现将pod分布式部署,并保存预期副本数,根据node失效状态自动在其他node上拉取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,所有master高可用主要针对kube-apiserver组件,而该组件以Http api提供服务,因此对他高可用与web服务器类型,增加负载均衡器对其负载均衡即可,并且可以水平宽容。
多master架构图:
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
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]:~
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=172.21.51.74 \
--advertise-address=172.21.51.74 \
...
vi /opt/kubernetes/cfg/kube-controller-manager.kubeconfig
server: https://172.21.51.74:6443
vi /opt/kubernetes/cfg/kube-scheduler.kubeconfig
server: https://172.21.51.74:6443
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://172.21.51.74:6443
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
[root@k8s-master2 ~]# kubectl get cs
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"}
[root@k8s-master2 ~]# kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-KjsoM5QmVBJmCjnyU4u1Hdm2ipxwCOo4qewY3X_egNc 80s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
[root@k8s-master2 ~]# kubectl certificate approve node-csr-KjsoM5QmVBJmCjnyU4u1Hdm2ipxwCOo4qewY3X_egNc
certificatesigningrequest.certificates.k8s.io/node-csr-KjsoM5QmVBJmCjnyU4u1Hdm2ipxwCOo4qewY3X_egNc approved
[root@k8s-master2 ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready 4h13m v1.20.9
k8s-master2 Ready 43s v1.20.9
k8s-node1 Ready 158m v1.20.9
k8s-node2 Ready 115m v1.20.9
yum install bash-completion -y
source /usr/share/bash-completion/bash_completion
source <(kubectl completion bash)
echo "source <(kubectl completion bash)" >> ~/.bashrc
kube-apiserver高可用架构图
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。如阿里云slb。
yum install epel-release -y
yum install nginx keepalived -y
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 $upstream_bytes_sent';
access_log /var/log/nginx/k8s-access.log main;
upstream k8s-apiserver {
server 172.21.51.71:6443; # Master1 APISERVER IP:PORT
server 172.21.51.74:6443; # Master2 APISERVER IP:PORT
}
server {
listen 16443; # 由于nginx与master节点复用,这个监听端口不能是6443,否则会冲突
proxy_pass k8s-apiserver;
}
}
http {
log_format main '$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
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 {
172.21.51.88/24
}
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|$$")
if [ "$count" -eq 0 ];then
exit 1
else
exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh
cat > /etc/keepalived/keepalived.conf << EOF
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id NGINX_BACKUP
}
vrrp_script check_nginx {
script "/etc/keepalived/check_nginx.sh"
}
vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.21.51.88/24
}
track_script {
check_nginx
}
}
EOF
准备上述配置文件中检查nginx运行状态的脚本:
cat > /etc/keepalived/check_nginx.sh << "EOF"
#!/bin/bash
count=$(ss -antp |grep 16443 |egrep -cv "grep|$$")
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
[root@k8s-master1 ~]# systemctl status nginx
● nginx.service - The nginx HTTP and reverse proxy server
Loaded: loaded (/usr/lib/systemd/system/nginx.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Sun 2021-08-15 06:14:50 CST; 26s ago
Process: 56349 ExecStartPre=/usr/sbin/nginx -t (code=exited, status=1/FAILURE)
Process: 56347 ExecStartPre=/usr/bin/rm -f /run/nginx.pid (code=exited, status=0/SUCCESS)
Aug 15 06:14:50 k8s-master1 systemd[1]: Starting The nginx HTTP and reverse proxy server...
Aug 15 06:14:50 k8s-master1 nginx[56349]: nginx: [emerg] unknown directive "stream" in /etc/nginx/nginx.conf:13
Aug 15 06:14:50 k8s-master1 nginx[56349]: nginx: configuration file /etc/nginx/nginx.conf test failed
Aug 15 06:14:50 k8s-master1 systemd[1]: nginx.service: control process exited, code=exited status=1
Aug 15 06:14:50 k8s-master1 systemd[1]: Failed to start The nginx HTTP and reverse proxy server.
Aug 15 06:14:50 k8s-master1 systemd[1]: Unit nginx.service entered failed state.
Aug 15 06:14:50 k8s-master1 systemd[1]: nginx.service failed.
需要下stream模块
yum install nginx-mod-stream -y
nginx -t
[root@k8s-master1 ~]# ip addr | grep 172
inet 172.21.51.71/24 brd 172.21.51.255 scope global noprefixroute ens33
inet 172.21.51.88/24 scope global secondary ens33
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
可以看到,在ens33网卡绑定了172.21.51.88 虚拟IP,说明工作正常。
关闭主节点nginx,测试vip是否漂移到备节点服务器
[root@k8s-master1 ~]# systemctl stop nginx
[root@k8s-master2 ~]# ip addr | grep 88
inet 172.21.51.88/24 scope global secondary ens33
找k8s集群中任意一个节点,使用curl ,使用curl查看k8s版本测试,使用vip访问
[root@k8s-node2 ~]# curl -k https://172.21.51.88:16443/version
{
"major": "1",
"minor": "20",
"gitVersion": "v1.20.9",
"gitCommit": "7a576bc3935a6b555e33346fd73ad77c925e9e4a",
"gitTreeState": "clean",
"buildDate": "2021-07-15T20:56:38Z",
"goVersion": "go1.15.14",
"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
[root@k8s-master2 ~]# tail /var/log/nginx/k8s-access.log -f
172.21.51.73 172.21.51.74:6443 - [15/Aug/2021:06:31:27 +0800] 200 420
172.21.51.73 172.21.51.71:6443 - [15/Aug/2021:06:31:32 +0800] 200 420
172.21.51.73 172.21.51.71:6443 - [15/Aug/2021:06:31:34 +0800] 200 420
172.21.51.73 172.21.51.74:6443 - [15/Aug/2021:06:31:35 +0800] 200 420
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172.21.51.71修改为172.21.51.88(VIP)。
在所有Worker Node执行:
sed -i 's#172.21.51.71:6443#172.21.51.88:16443#' /opt/kubernetes/cfg/*
systemctl restart kubelet kube-proxy
检查节点状态
[root@k8s-master1 ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready 4h56m v1.20.9
k8s-master2 Ready 44m v1.20.9
k8s-node1 Ready 3h22m v1.20.9
k8s-node2 Ready 158m v1.20.9
failed state.
Aug 15 06:14:50 k8s-master1 systemd[1]: nginx.service failed.
需要下stream模块
yum install nginx-mod-stream -y
nginx -t
###### 6. 查看keepalived工作状态
[root@k8s-master1 ~]# ip addr | grep 172
inet 172.21.51.71/24 brd 172.21.51.255 scope global noprefixroute ens33
inet 172.21.51.88/24 scope global secondary ens33
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
可以看到,在ens33网卡绑定了172.21.51.88 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
[root@k8s-master1 ~]# systemctl stop nginx
[root@k8s-master2 ~]# ip addr | grep 88
inet 172.21.51.88/24 scope global secondary ens33
##### 8.访问负载均衡器测试
找k8s集群中任意一个节点,使用curl ,使用curl查看k8s版本测试,使用vip访问
[root@k8s-node2 ~]# curl -k https://172.21.51.88:16443/version
{
“major”: “1”,
“minor”: “20”,
“gitVersion”: “v1.20.9”,
“gitCommit”: “7a576bc3935a6b555e33346fd73ad77c925e9e4a”,
“gitTreeState”: “clean”,
“buildDate”: “2021-07-15T20:56:38Z”,
“goVersion”: “go1.15.14”,
“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
[root@k8s-master2 ~]# tail /var/log/nginx/k8s-access.log -f
172.21.51.73 172.21.51.74:6443 - [15/Aug/2021:06:31:27 +0800] 200 420
172.21.51.73 172.21.51.71:6443 - [15/Aug/2021:06:31:32 +0800] 200 420
172.21.51.73 172.21.51.71:6443 - [15/Aug/2021:06:31:34 +0800] 200 420
172.21.51.73 172.21.51.74:6443 - [15/Aug/2021:06:31:35 +0800] 200 420
#### 7.4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172.21.51.71修改为172.21.51.88(VIP)。
在所有Worker Node执行:
sed -i ‘s#172.21.51.71:6443#172.21.51.88:16443#’ /opt/kubernetes/cfg/*
systemctl restart kubelet kube-proxy
检查节点状态
[root@k8s-master1 ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready 4h56m v1.20.9
k8s-master2 Ready 44m v1.20.9
k8s-node1 Ready 3h22m v1.20.9
k8s-node2 Ready 158m v1.20.9
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