一、Kubernetes的基本知识
-
Pod
Pod是若干个相关容器的组合,是一个逻辑概念,Pod包含的容器运行在同一个宿主机上,这些容器使用相同的网络命名空间、IP地址和端口,相互之间能通过localhost来发现和通信,共享一块存储卷空间。在Kubernetes中创建、调度和管理的最小单位是Pod。一个Pod一般只放一个业务容器和一个用于统一网络管理的网络容器。 -
Replication Controller
Replication Controller是用来控制管理Pod副本(Replica,或者称实例),Replication Controller确保任何时候Kubernetes集群中有指定数量的Pod副本在运行,如果少于指定数量的Pod副本,Replication Controller会启动新的Pod副本,反之会杀死多余的以保证数量不变。另外Replication Controller是弹性伸缩、滚动升级的实现核心。 -
Service
Service是真实应用服务的抽象,定义了Pod的逻辑集合和访问这个Pod集合的策略,Service将代理Pod对外表现为一个单一访问接口,外部不需要了解后端Pod如何运行,这给扩展或维护带来很大的好处,提供了一套简化的服务代理和发现机制。 -
Label
Label是用于区分Pod、Service、Replication Controller的Key/Value键值对,实际上Kubernetes中的任意API对象都可以通过Label进行标识。每个API对象可以有多个Label,但是每个Label的Key只能对应一个Value。Label是Service和Replication Controller运行的基础,它们都通过Label来关联Pod,相比于强绑定模型,这是一种非常好的松耦合关系。 -
Node
Kubernets属于主从的分布式集群架构,Kubernets Node(简称为Node,早期版本叫做Minion)运行并管理容器。Node作为Kubernetes的操作单元,将用来分配给Pod(或者说容器)进行绑定,Pod最终运行在Node上,Node可以认为是Pod的宿主机。
需求
目前生产部署Kubernetes集群主要有两种方式:
- 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。
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. 安装要求
部署Kubernetes集群服务器需要满足以下几个条件:
- 一台或多台机器,操作系统 CentOS7.x-86_x64
- 硬件配置:2GB或更多RAM,2个CPU或更多CPU,硬盘30GB或更多
- 集群中所有机器之间网络互通
- 可以访问外网,需要拉取镜像
- 禁止swap分区
软件环境:
软件 | 版本 |
---|---|
操作系统 | CentOS7.6.1810 |
Docker | docker-ce 19.03.11 |
Kubernetes | 1.18 |
服务器整体规划:
角色 | IP | 组件 |
---|---|---|
k8s-master1 | 192.168.0.10 | kube-apiserver,kube-controller-manager,kube-scheduler,etcd |
k8s-master2 | 192.168.0.11 | kube-apiserver,kube-controller-manager,kube-scheduler,etcd |
k8s-node1 | 192.168.0.20 | kubelet,kube-proxy,docker,etcd |
k8s-node2 | 192.168.0.30 | kubelet,kube-proxy,docker,etcd |
Load Balancer (master) | 192.168.0.40 | nginx L4 ,master节点的高可用 192.168.0.41(VIP) |
Load Balancer (Backup) | 192.168.0.41 | nginx L4 |
须知:考虑电脑配置环境较低,这么多虚拟机跑不动,所以这一套高可用集群分两部分实施,先部署一套单Master架构(192.168.0.10/20/30),再扩容为多Master架构(上述规划)。
单Master节点服务器规划:
角色 | IP | 组件 |
---|---|---|
k8s-master | 192.168.0.10 | kube-apiserver,kube-controller-manager,kube-scheduler,etcd |
k8s-node1 | 192.168.0.20 | kubelet,kube-proxy,docker etcd |
k8s-node2 | 192.168.0.30 | kubelet,kube-proxy,docker,etcd |
2. 系统初始化配置
# 关闭防火墙
systemctl stop firewalld
systemctl disable firewalld
# 关闭selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config
setenforce 0
# 关闭swap
swapoff -a
sed -ri 's/.*swap.*/#&/' /etc/fstab
# 根据规划设置主机名
hostnamectl set-hostname < name >
# 在master添加hosts
cat >> /etc/hosts << EOF
192.168.0.10 k8s-master
192.168.0.20 k8s-node1
192.168.0.30 k8s-node2
EOF
# 将桥接的IPv4流量传递到iptables的链
cat > /etc/sysctl.d/k8s.conf << EOF
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system # 生效
sysctl -p /etc/sysctl.d/k8s.conf
# 时间同步
yum install ntpdate -y
ntpdate time.windows.com
组件 | 使用的证书 |
---|---|
etcd | ca.pem,server.pem,server-key.pem |
flannel | ca.pem,server.pem,server-key.pem |
kube-apiserver | ca.pem,server.pem,server-key.pem |
kubelet(自动颁发) | ca.pem,ca-key.pem |
kube-proxy | ca.pem,kube-proxy.pem,kube-proxy-key.pem |
kubectl | ca.pem,admin.pem,admin-key.pem |
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 (k8s-master) | 192.168.0.10 |
etcd-2 (k8s-node1) | 192.168.0.20 |
etcd-3 (k8s-node2) | 192.168.0.30 |
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api-server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。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
2.2.1 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": {
"kubernetes": {
"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
[root@k8s-master etcd]# ll *pem
-rw-------. 1 root root 1675 Jul 10 15:32 ca-key.pem
-rw-r--r--. 1 root root 1265 Jul 10 15:32 ca.pem
2.2.2 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": [
"192.168.0.10",
"192.168.0.20",
"192.168.0.30"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing"
}
]
}
EOF
注: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!为了方便后期扩容也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
[root@k8s-master etcd]# ll server*pem
-rw-------. 1 root root 1679 Jul 10 15:38 server-key.pem
-rw-r--r--. 1 root root 1338 Jul 10 15:38 server.pem
2.3 从Github下载Etcd二进制文件
# 下载地址
#官网写了,因为新版3.4以上版本不支持旧版API,建议换成3.3的etcd
wget 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
在master节点上操作,为简化操作,可以将master节点生成的所有文件拷贝到俩台node节点
2.4.1 创建目录并解压二进制包
mkdir /opt/etcd/{bin,cfg,ssl} -p
tar zxvf etcd-v3.3.22-linux-amd64.tar.gz
chown -R root:root etcd-v3.3.22-linux-amd64
mv etcd-v3.3.22-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/
2.4.2 创建etcd配置文件
cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.0.10:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.0.10:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.0.10:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.0.10:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.0.10:2380,etcd-2=https://192.168.0.20:2380,etcd-3=https://192.168.0.30:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF
- ETCD_NAME:节点名称,集群中唯一
- ETCD_DATA_DIR:数据目录
- ETCD_LISTEN_PEER_URLS:集群通信监听地址
- ETCD_LISTEN_CLIENT_URLS:客户端访问监听地址
- ETCD_INITIAL_ADVERTISE_PEER_URLS:集群通告地址
- ETCD_ADVERTISE_CLIENT_URLS:客户端通告地址
- ETCD_INITIAL_CLUSTER:集群节点地址
- ETCD_INITIAL_CLUSTER_TOKEN:集群Token
- ETCD_INITIAL_CLUSTER_STATE:加入集群的当前状态,new是新集群,existing表示加入已有集群
2.4.3 配置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
2.4.3 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/etcd/ca*pem ~/TLS/etcd/server*pem /opt/etcd/ssl/
2.4.5 启动并设置自启动
systemctl daemon-reload
systemctl restart etcd
systemctl enable etcd
# 如果报错无法启动,则需要将其他etcd节点设置完成后才可以启动
2.4.6 将master节点生成所有的文件拷贝到两台node节点
scp -rp /opt/etcd/ k8s-node1:/opt/
scp -rp /opt/etcd/ k8s-node2:/opt/
scp -rp /usr/lib/systemd/system/etcd.service k8s-node1:/usr/lib/systemd/system/
scp -rp /usr/lib/systemd/system/etcd.service k8s-node2:/usr/lib/systemd/system/
2.4.7 在node节点分别修改etcd.conf配置文件中的节点名称和当前服务器IP
#node1和node2节点都进行修改
vim /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" # 修改此处为当前服务器IP
ETCD_LISTEN_PEER_URLS="https://192.168.0.20:2380" # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://192.168.0.20:2379" # 修改此处为当前服务器IP
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.0.20:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.0.20:2379" # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.0.10:2380,etcd-2=https://192.168.0.20:2380,etcd-3=https://192.168.0.30:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
# 最后启动etcd并设置开机启动
systemctl daemon-reload
systemctl restart etcd
systemctl enable etcd
[root@k8s-master etcd]# netstat -lntup|grep etcd
tcp 0 0 192.168.0.10:2379 0.0.0.0:* LISTEN 10529/etcd
tcp 0 0 192.168.0.10:2380 0.0.0.0:* LISTEN 10529/etcd
#为三台节点都创建系统执行指令命令
cp /opt/etcd/bin/etcdctl /usr/bin/
2.4.8 查看etcd集群状态
[root@k8s-master etcd]# etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://192.168.0.10:2379,https://192.168.0.20:2379,https://192.168.0.30:2379" endpoint health
https://192.168.0.30:2379 is healthy: successfully committed proposal: took = 18.649662ms
https://192.168.0.20:2379 is healthy: successfully committed proposal: took = 20.469511ms
https://192.168.0.10:2379 is healthy: successfully committed proposal: took = 22.428573ms
如果输出上面信息,就说明Etcd集群部署成功。如果有问题先看日志:
/var/log/message
或journalctl -u etcd
三、所有节点部署Docker
image我这里采用yum安装,用二进制安装也一样
# 1. 卸载旧版本
yum remove docker \
docker-client \
docker-client-latest \
docker-common \
docker-latest \
docker-latest-logrotate \
docker-logrotate \
docker-engine
# 2. 使用存储库安装
yum install -y yum-utils
# 3. 设置镜像仓库(修改为国内源地址)
yum-config-manager \
--add-repo \
http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
# 5. 更新索引
yum makecache fast
# 4. 安装docker相关的依赖 默认最新版(docker-ce:社区版 ee:企业版)
yum install docker-ce docker-ce-cli containerd.io -y
#5. 安装特定docker版本(先列出列出可用版本)
yum list docker-ce --showduplicates | sort -r
yum install docker-ce-19.03.9 docker-ce-cli-19.03.9 containerd.io
# 所有节点设置防火墙规则,并让生效
vim /lib/systemd/system/docker.service
[Service]
ExecStartPost=/sbin/iptables -I FORWARD -s 0.0.0.0/0 -j ACCEPT
# 7. 启动docker
systemctl enable docker
systemctl restart docker
# 8. 查看版本
[root@k8s-master ~]# docker --version
Docker version 19.03.11, build 42e35e61f3
# 9. 配置docker镜像加速器
## 镜像加速器:阿里云加速器,daocloud加速器,中科大加速器
## Docker 中国官方镜像加速:https://registry.docker-cn.com
mkdir -p /etc/docker
tee /etc/docker/daemon.json <<-'EOF'
{
"registry-mirrors": ["https://registry.docker-cn.com"]
}
EOF
systemctl daemon-reload
systemctl restart docker
四、部署Master节点
-
kube-apiserver,
-
kube-controller-manager,
-
kube-scheduler
4.1 生成kube-apiserver证书
4.1.1 自签CA证书颁发机构
cd /root/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-master k8s]# ll *pem
-rw-------. 1 root root 1675 Jul 13 14:49 ca-key.pem
-rw-r--r--. 1 root root 1359 Jul 13 14:49 ca.pem
4.1.2 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",
"10.240.0.1",
"172.16.0.1",
"127.0.0.1",
"192.168.0.10",
"192.168.0.11",
"192.168.0.12",
"192.168.0.20",
"192.168.0.21",
"192.168.0.22",
"192.168.0.30",
"192.168.0.31",
"192.168.0.32",
"192.168.0.40",
"192.168.0.41",
"192.168.0.42",
"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
#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
[root@k8s-master k8s]# ll server*pem
-rw-------. 1 root root 1679 Jul 13 14:55 server-key.pem
-rw-r--r--. 1 root root 1700 Jul 13 14:55 server.pem
4.2下载二进制文件包并解压
下载地址: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md#v1183
打开链接会发现里面有很多包,下载一个最新版server包就够了,包含了Master和Node二进制文件。
# 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/
4.3 部署kube-apiserver
4.3.1. 创建配置文件
cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--etcd-servers=https://192.168.0.10:2379,https://192.168.0.20:2379,https://192.168.0.30:2379 \\
--bind-address=192.168.0.10 \\
--secure-port=6443 \\
--advertise-address=192.168.0.10 \\
--allow-privileged=true \\
--service-cluster-ip-range=10.0.0.0/24 \\
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \\
--authorization-mode=RBAC,Node \\
--enable-bootstrap-token-auth=true \\
--token-auth-file=/opt/kubernetes/cfg/token.csv \\
--service-node-port-range=30000-32767 \\
--kubelet-client-certificate=/opt/kubernetes/ssl/server.pem \\
--kubelet-client-key=/opt/kubernetes/ssl/server-key.pem \\
--tls-cert-file=/opt/kubernetes/ssl/server.pem \\
--tls-private-key-file=/opt/kubernetes/ssl/server-key.pem \\
--client-ca-file=/opt/kubernetes/ssl/ca.pem \\
--service-account-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--etcd-cafile=/opt/etcd/ssl/ca.pem \\
--etcd-certfile=/opt/etcd/ssl/server.pem \\
--etcd-keyfile=/opt/etcd/ssl/server-key.pem \\
--audit-log-maxage=30 \\
--audit-log-maxbackup=3 \\
--audit-log-maxsize=100 \\
--audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
EOF
注:上面两个\\
第一个是转义符,第二个是换行符,使用转义符是为了使用EOF保留换行符。
--logtostderr:启用日志
--log-dir:日志目录
--v:日志等级,越小越多
--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,决定是否启用k8s高级功能
--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-https:apiserver主动访问kubectl时默认使用https
--kubelet-client-xxx:apiserver访问kubelet客户端证书
--tls-xxx-file:apiserver https证书
--etcd-xxxfile:连接Etcd集群证书
--audit-log-xxx:审计日志
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。
此图仅用来学习,不为本人原创
image
4.3.2 拷贝刚才生成的证书
cp ~/TLS/k8s/ca*pem ~/TLS/k8s/server*pem /opt/kubernetes/ssl/
4.3.3 创建配置文件中的token文件
# 获取16位token随机值的命令
head -c 16 /dev/urandom | od -An -t x | tr -d ' '
863b2ebebecffbb3a6493ff15dfc57c6
# 添加token文件(格式:token,用户名,UID,用户组)
BOOTSTRAP_TOKEN=863b2ebebecffbb3a6493ff15dfc57c6
cat > /opt/kubernetes/cfg/token.csv <<EOF
${BOOTSTRAP_TOKEN},kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF
4.3.4 配置systemd启动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
4.3.5 启动并设置开机启动
systemctl daemon-reload
systemctl restart kube-apiserver
systemctl enable kube-apiserver
4.3.6 授权kubelet-bootstrapper用户允许请求证书
kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap
4.4 部署controller-manager
5.4.1 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 \\
--master=127.0.0.1:8080 \\
--bind-address=127.0.0.1 \\
--allocate-node-cidrs=true \\
--cluster-cidr=10.244.0.0/16 \\
--service-cluster-ip-range=10.0.0.0/24 \\
--cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem \\
--cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--root-ca-file=/opt/kubernetes/ssl/ca.pem \\
--service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--experimental-cluster-signing-duration=87600h0m0s"
EOF
- –master:通过本地非安全本地端口8080连接apiserver
- –leader-elect:当该组件启动多个时,自动选举(HA)
- –cluster-signing-cert-file / –cluster-signing-key-file:自动为kubelet颁发证书的CA,与apiserver保持一致
4.4.2 配置systemd启动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
4.4.3 启动并设置开机启动
systemctl daemon-reload
systemctl restart kube-controller-manager
systemctl enable kube-controller-manager
4.5 部署kube-scheduler
4.5.1 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 \\
--master=127.0.0.1:8080 \\
--bind-address=127.0.0.1"
EOF
- –master:通过本地非安全本地端口8080连接apiserver。
- –leader-elect:当该组件启动多个时,自动选举(HA)
4.5.2 配置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
4.5.3 启动并设置开机启动
systemctl daemon-reload
systemctl restart kube-scheduler
systemctl enable kube-scheduler
4.6 查看集群状态
所有组件都已经启动成功,通过kubectl工具查看当前集群组件状态
[root@k8s-master TLS]# kubectl get cs
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-0 Healthy {"health":"true"}
etcd-1 Healthy {"health":"true"}
etcd-2 Healthy {"health":"true"}
输出如上内容说明Master节点组件运行正常
五、部署Node节点
5.1 创建工作目录并拷贝二进制文件
如果想把Master也当做Node节点的话,也可以在Master节点上安装kubelet和kube-proxy
# 1.在所有node节点创建工作目录
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}
# 2. 从master节点上解压的kubernetes压缩包中拷贝文件到所有node节点
for ip in 20 30 ;do scp -rp ./kubernetes/server/bin/{kubelet,kube-proxy} 192.168.0.$ip:/opt/kubernetes/bin/ ;done
5.2 部署kubelet
5.2.1 创建配置文件
pod的基础容器镜像改为国内的下载的镜像地址或自己的Docker Hub
registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0
245684979/pause-amd64:3.0
# node1节点
cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-node1 \\
--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=245684979/pause-amd64:3.0"
EOF
# node2节点
cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-node2 \\
--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=245684979/pause-amd64:3.0"
EOF
- –hostname-override:显示主机名称,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,用于实现Kubernetes集群里pod之间的网络通讯
5.2.2 配置参数文件
# node1节点和node2节点配置相同
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
5.2.3 生成bootstrap.kubeconfig文件
在master节点将node节点需要的CA证书文件拷贝过去
[root@k8s-master ~]# scp /opt/kubernetes/ssl/ca.pem k8s-node1:/opt/kubernetes/ssl
[root@k8s-master ~]# scp /opt/kubernetes/ssl/ca.pem k8s-node2:/opt/kubernetes/ssl
在master上查看Token文件的随机值
[root@k8s-master ~]# cat /opt/kubernetes/cfg/token.csv
863b2ebebecffbb3a6493ff15dfc57c6,kubelet-bootstrap,10001,"system:kubelet-bootstrapper"
在master上生成bootstrap.kubeconfig文件
KUBE_APISERVER="https://192.168.0.10:6443" # apiserverIP:PORT
TOKEN="863b2ebebecffbb3a6493ff15dfc57c6" # 与token.csv里保持一致
# 设置集群参数
kubectl config set-cluster kubernetes \
--certificate-authority=/opt/kubernetes/ssl/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=bootstrap.kubeconfig
# 设置客户端认证参数
kubectl config set-credentials "kubelet-bootstrap" \
--token=${TOKEN} \
--kubeconfig=bootstrap.kubeconfig
# 设置上下文参数
kubectl config set-context default \
--cluster=kubernetes \
--user="kubelet-bootstrap" \
--kubeconfig=bootstrap.kubeconfig
# 设置默认上下文
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig
# 保存到配置文件路径下
cp bootstrap.kubeconfig /opt/kubernetes/cfg/
# 拷贝到node节点的/opt/kubernetes/cfg/下
scp -rp /opt/kubernetes/cfg/bootstrap.kubeconfig k8s-node1:/opt/kubernetes/cfg
scp -rp /opt/kubernetes/cfg/bootstrap.kubeconfig k8s-node2:/opt/kubernetes/cfg
5.2.4 配置systemd管理kubelet
# node1节点和node2节点配置相同
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
5.2.5 启动并设置开机启动
systemctl daemon-reload
systemctl restart kubelet
systemctl enable kubelet
5.2.6 批准kubelet证书申请并加入集群
# 查看kubelet证书请求
[root@k8s-master ~]# kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-1-0ue-UfiHoWna5v68PDMgrxk1cPPNFLG3EtoUUCdwk 85s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
node-csr-zjBOatKIi69UhbL7ypngHFw5C7xfjCOZnFyTG4Ux1H0 76s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
# 批准请求
kubectl certificate approve node-csr-1-0ue-UfiHoWna5v68PDMgrxk1cPPNFLG3EtoUUCdwk
kubectl certificate approve node-csr-zjBOatKIi69UhbL7ypngHFw5C7xfjCOZnFyTG4Ux1H0
# 查看node节点状态
[root@k8s-master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-node1 NotReady <none> 1s v1.18.5
k8s-node2 NotReady <none> 1s v1.18.5
#@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
5.4.1 创建配置文件
# node1节点和node2节点配置相同
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
5.4.2 配置参数文件
# node1
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-node1
clusterCIDR: 10.0.0.0/24
EOF
# node2
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-node2
clusterCIDR: 10.0.0.0/24
EOF
5.4.3 生成kube-proxy.kubeconfig文件
在master节点生成kube-proxy证书
# 切换到存放证书目录
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
[root@k8s-master k8s]# ll kube-proxy*pem
-rw-------. 1 root root 1679 Jul 14 15:41 kube-proxy-key.pem
-rw-r--r--. 1 root root 1403 Jul 14 15:41 kube-proxy.pem
5.4.3 生成kube-proxy.kubeconfig文件
在master节点生成kube-proxy.kubeconfig文件
KUBE_APISERVER="https://192.168.0.10:6443"
kubectl config set-cluster kubernetes \
--certificate-authority=/opt/kubernetes/ssl/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-credentials kube-proxy \
--client-certificate=./kube-proxy.pem \
--client-key=./kube-proxy-key.pem \
--embed-certs=true \
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-context default \
--cluster=kubernetes \
--user=kube-proxy \
--kubeconfig=kube-proxy.kubeconfig
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
# 保存到配置文件路径下
cp kube-proxy.kubeconfig /opt/kubernetes/cfg/
# 拷贝到node节点的/opt/kubernetes/cfg/下
scp -rp /opt/kubernetes/cfg/kube-proxy.kubeconfig k8s-node1:/opt/kubernetes/cfg
scp -rp /opt/kubernetes/cfg/kube-proxy.kubeconfig k8s-node2:/opt/kubernetes/cfg
5.4.4 配置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
5.4.5 启动并设置开机启动
systemctl daemon-reload
systemctl restart kube-proxy
systemctl enable kube-proxy
六、部署CNI网络
6.1 Kubernetes网络模型 (CNI)介绍
容器网络接口
kubernetes网络模型设计的基本要求:
- 一个pod一个ip
- 每个pod独立的ip,pod内所有容器共享网络(同一个ip)
- 所有容器都可以与所有其他容器通信
- 所有节点都可以与所有容器通信
目前支持的技术
. image
最常用的是flannel和calic
- Flannel:适合百台以下服务器,小规模集群,使用操作简单
- calico:适合数百台以上,大规模集群
6.2 下载安装包
下载最新版地址:https://github.com/containernetworking/plugins/releases/tag/v0.8.6
wget https://github.com/containernetworking/plugins/releases/download/v0.8.6/cni-plugins-linux-amd64-v0.8.6.tgz
# 解压二进制包并移动到默认工作目录
mkdir -p /opt/cni/bin
tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin
# 在node节点创建cni目录
mkdir -p /opt/cni/bin
# 在master节点上拷贝到node节点的cni目录
scp -rp /opt/cni/bin/* k8s-node1:/opt/cni/bin/
scp -rp /opt/cni/bin/* k8s-node2:/opt/cni/bin/
6.3 部署CNI flannel 网络
所有的节点都需要安装flannel
# 部署CNI网络(网络问题可以多尝试几次)
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
# 默认镜像地址无法访问外网,可以修改为docker hub镜像仓库
# 245684979/flannel:v0.12.0-amd64
sed -ri "s#quay.io/coreos/flannel:.*-amd64#245684979/flannel:v0.11.0-amd64#g" kube-flannel.yml
#添加"--iface=eth0"一句指定网卡
...
containers:
- name: kube-flannel
image: quay.io/coreos/flannel:v0.12.0-amd64
command:
- /opt/bin/flanneld
args:
- --ip-masq
- --kube-subnet-mgr
- --iface=eth0
[root@k8s-master ~]# kubectl apply -f kube-flannel.yml
#查看kube-system下的pod
[root@k8s-master cni]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
kube-flannel-ds-amd64-lklmb 1/1 Running 0 74s
kube-flannel-ds-amd64-t5tcc 1/1 Running 0 74s
#查看node状态
[root@k8s-master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-node1 Ready <none> 2m3s v1.18.5
k8s-node2 Ready <none> 104s v1.18.5
6.4 授权apiserver访问kubelet
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
八、部署Dashboard和CoreDNS
8.1 部署Dashboard
https://github.com/kubernetes/dashboard
wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.3/aio/deploy/recommended.yaml
默认Dashboard只能集群内部访问,修改Service为NodePort类型,暴露到外部
# 修改yaml文件
[root@k8s-master yaml]# vim recommended.yaml (32gg)
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kubernetes-dashboard
spec:
ports:
- port: 443
targetPort: 8443
nodePort: 30001 #添加类型
type: NodePort
selector:
k8s-app: kubernetes-dashboard
# 生成dashboard
kubectl apply -f recommended.yaml
# 查看dashboard状态
[root@k8s-master yaml]# kubectl get pods,svc -n kubernetes-dashboard
NAME READY STATUS RESTARTS AGE
pod/dashboard-metrics-scraper-6b4884c9d5-gqs7b 0/1 ContainerCreating 0 34s
pod/kubernetes-dashboard-7f99b75bf4-mgg46 0/1 ContainerCreating 0 35s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/dashboard-metrics-scraper ClusterIP 10.0.0.105 <none> 8000/TCP 35s
service/kubernetes-dashboard NodePort 10.0.0.80 <none> 443:30001/TCP 35s
查看pod日志
kubectl -n kube-system logs -f kube-flannel-ds-amd64-24jxf
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