3.2 二进制方式安装k8s集群
二进制方式
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降低了部署门槛, 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 。
1.1 安装要求
在开始之前, 部署kubernetes集群集群需要满足一下几个条件:
- 一台或多台机器 , 操作系统CentOS7.x-86_x64
- 硬件配置: 2G或更多RAM , 2个CPU或更多CPU , 硬盘30GB或更多
- 集群中所有集群之间网络互通
- 可以访问外网, 需要拉取镜像, 如果服务器不能上网, 需要提前下载镜像并导入节点
- 禁止swap分区
1.2 准备环境
软件环境:
软件 | 版本 |
---|---|
操作系统 | CentOS7.6_x86_64 |
Docker | 19-ce |
Kubenetes | 1.18 |
服务器整体规划:
角色 | IP | 组件 |
---|---|---|
k8s-master1 | 192.168.31.71 | Kube-apiserver,kube-controller-manager,kube-scheduler,etcd |
K8s-master2 | 192.168.31.74 | Kube-apiserver,kube-controller-manager,kube-scheduler |
K8s-node1 | 192.168.31.72 | Kubelet,kube-proxy,docker, etcd |
K8s-node2 | 192.168.31.73 | Kubelet,kube-proxy,docker ,etcd |
Load Balancer(Master) | 192.168.31.81 192.168.31.88(vip) |
Nginx L4 |
Load Balancer(Backup) | 192.168.31.82 | Nginx L4 |
须知:考虑到有些朋友电脑配置较低, 这么多虚拟机跑不动, 所以这一套高可用集群分两部分实施, 先部署一套单Master架构(192.168.31.71、72、73),再扩容为多Master架构(上述规划),顺便熟悉一下Master扩容流程。
单Master架构图
单Master服务器规划:
角色 | IP | 组件 |
---|---|---|
k8s-master | 192.168.31.71 | Kube-apiserver,kube-controller-manager,kube-scheduler,etcd |
K8s-node1 | 192.168.31.72 | Kubelet,kube-proxy,docker, etcd |
K8s-node2 | 192.168.31.73 | Kubelet,kube-proxy,docker ,etcd |
1.3 操作系统初始化配置
#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 k8s-master
hostnamectl set-hostname k8s-node1
hostnamectl set-hostname k8s-node2
#在master添加hosts
cat >> /etc/hosts << EOF
192.168.31.71 k8s-master
192.168.31.72 k8s-node1
192.168.31.73 k8s-node2
EOF
# 将桥接的IPv4流量传递到iptables的链
cat > /etc/sysctl.d/k8s.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system
#时间同步
yum install ntpdate -y
ntpdate time.windows.com
二部署ETCD 集群
ETCD是一个分布式键值存储系统, kubernetes使用Etcd进行数据存储, 所以先准备一个Etcd数据库, 为了解决单点故障, 应采用集群方式部署, 这里使用3台组件集群, 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台集群故障
节点名称 | IP |
---|---|
etcd-1 | 192.168.31.71 |
etcd-2 | 192.168.31.72 |
etcd-3 | 192.168.31.73 |
注:为了节省集群, 这里与k8s节点机器复用, 也可以独立于k8s 集群之外部署, 只要apiserver能连接到就行 。
2.1 准备cfssl证书生成工具
cfssl是一个开源的证书管理工具, 使用json文件生成证书, 相比openssl更方便使用
赵任意一台服务器操作, 这里用master节点
wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mv cfssl-certinfo_linux-amd64 /usr/local/bin/cfssl-certinfo
2.2 生成Etcd证书
1.自签名证书颁发机构(CA)
创建工作目录
mkdir ~/TLS/{etcd,k8s} -p
cd TLS/etcd/
自签CA:
cat > ca-config.json << EOF
{
"signing": {
"default": {
"expiry": "87600h"
},
"profiles": {
"www": {
"expiry": "87600h",
"usages": [
"signing",
"key encipherment",
"server auth",
"client auth"
]
}
}
}
}
EOF
cat > ca-csr.json << EOF
{
"CN": "etcd CA",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "Beijing",
"ST": "Beijing"
}
]
}
EOF
生成证书:
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
ls *pem
ca-key.pem ca.pem
2.3使用自签CA签发Etcd HTTPS证书
创建证书申请文件:
cat > server-csr.json << EOF
{
"CN": "etcd",
"hosts": [
"192.168.31.71",
"192.168.31.72",
"192.168.31.73"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing"
}
]
}
EOF
注: 上述文件hosts字段中IP为所有etcd节点的集群内部通信IP , 一个都不能少?为了方便后期扩容可以多写几个预留的IP
生成证书:
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json |cfssljson -bare server
ls server*pem
server-key.pem server.pem
2.4 从Github下载二进制文件
下载地址
https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz
2.5 部署Etcd集群
以下在节点1上操作, 为了简化操作, 待会将节点1生成的所有文件拷贝到节点2和节点3
1.创建工作目录并压缩二进制包(三个节点都需要)
mkdir /opt/etcd/{bin,cfg,ssl} -p
tar zxvf etcd-v3.4.9-linux-amd64.tar.gz
mv etcd-v3.4.9-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/
2.创建etcd配置文件
- 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: 客户端通过地址
- 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
Master
cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.71:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF
3.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
4.拷贝刚才生成的证书
把刚才生成的证书拷贝到配置文件中的路径:
cp ~/TLS/etcd/ca*pem ~/TLS/etcd/server*pem /opt/etcd/ssl/
5.启动并设置开机启动
systemctl daemon-reload
systemctl start etcd
systemctl enable etcd
6.将上面节点1所有生成的文件拷贝到节点2和节点3
scp -r /opt/etcd/ root@192.168.31.72:/opt/
scp /usr/lib/systemd/system/etcd.service root@192.168.31.72:/usr/lib/systemd/system/
scp -r /opt/etcd/ root@192.168.31.73:/opt/
scp -r /usr/lib/systemd/system/etcd/service root@192.168.31.73:/usr/lib/systemd/system/
然后在节点2和节点3 分别修改etcd.conf配置文件中的节点名称和当前服务器IP:
Node1
cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-2"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.72:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.72:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.72:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.72:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF
node2
cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-3"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.73:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.73:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.73:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.73:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF
7. 查看集群状态
ETCD_API=3 /opt/etcd/bin/etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379" endpoint health
https://192.168.31.71:2379 is healthy: successfully committed proposal: took = 21.289133ms
https://192.168.31.72:2379 is healthy: successfully committed proposal: took = 165.432479ms
https://192.168.31.73:2379 is healthy: successfully committed proposal: took = 167.897358ms
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
k8s现在使用的是etcd v3,必须提供ca、key、cert,否则会出现Error: context deadline exceeded
不加–endpoint参数时,默认访问的127.0.0.1:2379,而使用–endpoint参数时,必须提供ca,key,cert
8.配置环境变量
#设置etcdctl为v3版本
export ETCDCTL_API=3
#设置etcd的端点信息,即etcd集群的ip:port,以逗号分隔
export ETCDCTL_ENDPOINTS=https://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379
#设置证书的环境变量
export ETCDCTL_CACERT=/opt/etcd/ssl/ca.pem
export ETCDCTL_CERT=/opt/etcd/ssl/server.pem
export ETCDCTL_KEY=/opt/etcd/ssl/server-key.pem
三 安装docker
下载地址:
https://download.docker.com/linux/static/stable/x86_64/docker-19.03.0.tgz
以下在所有节点操作 。 这里采用二进制安装 , 用yum安装也一样
3.1 解压二进制包
tar zxvf docker-19.03.0.tgz
mv docker/* /usr/bin/
3.2 system管理docker
cat > /usr/lib/systemd/system/docker.service << EOF
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target
[Service]
Type=notify
ExecStart=/usr/bin/dockerd
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TimeoutStartSec=0
Delegate=yes
KillMode=process
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s
[Install]
WantedBy=multi-user.target
EOF
3.3 创建配置文件
mkdir /etc/docker
tee /etc/docker/daemon.json <<-'EOF'
{
"registry-mirrors": ["https://f4573wwn.mirror.aliyuncs.com"]
}
EOF
registry-mirrors 阿里云镜像加速器
3.4 启动并设置开机启动
systemctl daemon-reload
systemctl start docker
systemctl enable docker
四、部署master node
4.1 生成kube-apiserver证书
1. 自签证书颁发机构(CA)
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 -
ls *pem
ca-key.pem ca.pem
2.使用自签CA签发kube-apiserver HTTPS证书
创建证书申请文件:
cd ~/install-k8s/TLS/k8s
cat > server-csr.json << EOF
{
"CN": "kubernetes",
"hosts": [
"10.0.0.1",
"127.0.0.1",
"192.168.31.71",
"192.168.31.72",
"192.168.31.73",
"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字段中可以多写几个ip包含master、LB、VIP IP、,一个都不能少 , 为了方便后期扩容可以多写几个预留的IP。
生成证书:
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json |cfssljson -bare server
ls server*pem
server-key.pem server.pem
4.2 从Github下载二进制文件
下载地址:
https://github.com/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md#v1183
https://gitee.com/RaYong8080/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md#v1183
注: 打开链接你会发现里面有很多包 , 下载一个server包就够了 ,包含了master和worker node的二进制文件 。
4.3 解压二进制包(所有节点)
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}
tar xf 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/
scp kubectl root@192.168.31.73:/usr/bin/
4.4 部署kube-apiserver
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://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379 \\
--bind-address=192.168.31.71 \\
--secure-port=6443 \\
--advertise-address=192.168.31.71 \\
--allow-privileged=true \\
--service-cluster-ip-range=10.0.0.0/24 \\
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \\
--authorization-mode=RBAC,Node \\
--enable-bootstrap-token-auth=true \\
--token-auth-file=/opt/kubernetes/cfg/token.csr \\
--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
- --logtostderr: 启动日志
- --v: 日志登记
- --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
- --adverttse-address: 集群通告地址
- --allow-privileged: 启动授权
- --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, 启动RBAC授权和节点自管理
- --enable-bootstrap-token-auth: 启动TLS bootstrap机制
- --token-auth-file: bootstrap token文件
- --service-node-port-range: Service noeport类型默认分配端口范围
- --kubelet-client-xxx: apiserver访问kubelet客户端证书
- --tls-xx-file: apiserver https证书
- --etcd-xxxfile: 连接Etcd集群证书
- --audit-log-xxx: 审计日志
2. 拷贝刚才生成的正式
把刚才生成的正式拷贝到配置文件中的路径:
cp ~/TLS/k8s/ca*pem ~/TLS/k8s/server*pem /opt/kubernetes/ssl/
3.启动TLS Bootstrapping 机制
TLS Bootstraping:Master apiserver启动TLS认证后 ,Node节点kubelet和kube-proxy要与kube-apiserver进展通信 , 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, kebelet会以一个低权限用户自动向apiserver申请证书, kubelet的证书由apiserver动态签署 。 所以强烈建议在Node上使用这种方式, 目前主要用于kubelet ,kube-proxy还是由我们统一颁发一个证书 。
TLS bootstraping 工作流程:
创建上述配置文件中token文件:
cat > /opt/kubernetes/cfg/token.csr << EOF
b231eb5bbb461b30fa239031a1f191d6,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF
格式:token , 用户名 ,UID ,用户组
token也可自行生成替换
head -c 16 /dev/urandom | od -An -t x | tr -d ' '
4.systemd管理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
5.启动并设置开机启动
systemctl daemon-reload
systemctl start kube-apiserver
systemctl enable kube-apiserver
6.授权kubelet-bootstrap用户允许请求证书
kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap
4.5 部署kube-controller-manager
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
- --cluster-cidr: 集群pod分配的ip地址 ,flannel 的Network 地址一致
- --service-cluster-ip-range: 集群service地址
- --leader-elect: 当该组件启动多个时 , 自动选举(HA)
- --cluster-signing-cert-file/--cluster-signing-key-file: 自动为kubelet颁发证书的CA ,与apiserver保持一致
2.systemd管理controller-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
3.启动并设置开机启动
systemctl daemon-reload
systemctl start kube-controller-manager
systemctl enable kube-controller-manager
4.6 部署kube-scheduler
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)
2.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
3.启动并设置开机启动
systemctl daemon-reload
systemctl start kube-scheduler
systemctl enable kube-scheduler
4.查看集群状态
所有组件都已经启动成功, 通过kubectl工具查看当前集群组件状态:
kubectl get cs
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-1 Healthy {"health":"true"}
etcd-0 Healthy {"health":"true"}
etcd-2 Healthy {"health":"true"}
如上输出说明master 节点组件运行正常
五、部署Worker Node
下面还是在master node上操作 , 即同时作为worker node
5.1 创建工作目录并拷贝二进制文件
在所有worder node创建工作目录:
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}
从master节点拷贝
cd kubernetes/server/bin
cp kubelet kube-proxy /opt/kubernetes/bin #本地拷贝
5.2 部署kubelet
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-master \\
--network-plugin=cni \\
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \\
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \\
--config=/opt/kubernetes/cfg/kubelet-config.yml \\
--cert-dir=/opt/kubernetes/ssl \\
--pod-infra-container-image=lizhenliang/pause-amd64:3.0"
EOF
- --hostname-override: 显示名称, 集群中唯一
- --network-plugin: 启用CNI
- --kubeconfig: 空路径, 会自动生成, 后面用于连接apiserver
- --bootstrap-kubeconfig: 首次启动向apiserver申请证书
- --config: 配置参数文件
- --cert-dir: kubelet证书生成目录
- --pod-infra-container-image: 管理Pod网络容器的镜像
2.配置参数文件
cat > /opt/kubernetes/cfg/kubelet-config.yml << EOF
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 0.0.0.0
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS:
- 10.0.0.2
clusterDomain: cluster.local
failSwapOn: false
authentication:
anonymous:
enabled: false
webhook:
cacheTTL: 2m0s
enabled: true
x509:
clientCAFile: /opt/kubernetes/ssl/ca.pem
authorization:
mode: Webhook
webhook:
cacheAuthorizedTTL: 5m0s
cacheUnauthorizedTTL: 30s
evictionHard:
imagefs.available: 15%
memory.available: 100Mi
nodefs.available: 10%
nodefs.inodesFree: 5%
maxOpenFiles: 1000000
maxPods: 110
EOF
3.生成bootstrap.kubeconfig文件
KUBE_APISERVER="https://192.168.31.71:6443" #apiserver IP:port
TOKEN="b231eb5bbb461b30fa239031a1f191d6" #与token.csr 里报错一致
b231eb5bbb461b30fa239031a1f191d6
#生成kubelet bootstrap kubeconfig 配置文件
kubectl config set-cluster kubernetes \
--certificate-authority=/opt/kubernetes/ssl/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=bootstrap.kubeconfig
kubectl config set-credentials "kubelet-bootstrap" \
--token=${TOKEN} \
--kubeconfig=bootstrap.kubeconfig
kubectl config set-context default \
--cluster=kubernetes \
--user="kubelet-bootstrap" \
--kubeconfig=bootstrap.kubeconfig
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig
拷贝配置文件路径:
cp bootstrap.kubeconfig /opt/kubernetes/cfg/
4.systemd管理kubelet
cat > /usr/lib/systemd/system/kubelet.service << EOF
[Unit]
Description=Kubernetes Kubelet
After=docker.service
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kubelet.conf
ExecStart=/opt/kubernetes/bin/kubelet \$KUBELET_OPTS
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
5.启动并设置开机启动
systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet
报错
cat /var/log/messages|grep kubelet|grep -i error
5.3 批准kubelet证书申请并加入集群
#查看kubelet 证书请求
kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-RrAbmArhPhH9U4xm7oMqPY4oauQybeHvub9VMAj9VoM 48s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
#批准申请
kubectl certificate approve node-csr-RrAbmArhPhH9U4xm7oMqPY4oauQybeHvub9VMAj9VoM
# 查看节点
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master NotReady <none> 17s v1.18.3
注由于网络插件还没有部署 , 节点会没有准备就绪NotReady
如果要kubectl 访问 kube-apiserver需要设置
kubectl 默认是访问localhost:8080
配置kubeconfig
#创建配置文件目录
mkdir .kube
#创建kubeconfig
touch config
将 kubeconfig内容放入.kube/config文件中
配置环境变量
添加: KUBECONFIG=$HOME/.kube/config 到环境变量,并刷新:source /etc/profile
export KUBECONFIG
5.4 部署kube-proxy
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-master
clusterCIDR: 10.0.0.0/24
mode: "ipvs"
EOF
3.生成kube-proxy.kubecofig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_APISERVER="https://192.168.31.71:6443"
kubectl config set-cluster kubernetes \
--certificate-authority=/opt/kubernetes/ssl/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-credentials kube-proxy \
--client-certificate=./kube-proxy.pem \
--client-key=./kube-proxy-key.pem \
--embed-certs=true \
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-context default \
--cluster=kubernetes \
--user=kube-proxy \
--kubeconfig=kube-proxy.kubeconfig
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
拷贝到配置文件指定路径:
cp kube-proxy.kubeconfig /opt/kubernetes/cfg/
4. systemd管理kube-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
5.5 部署CNI网络
先准备好CNI二进制文件:
下载地址:
https://github.com/containernetworking/plugins/releases/download/v0.8.6/cni-plugins-linux-amd64-v0.8.6.tgz
解压二进制包并移动到默认工作目录:
mkdir /opt/cni/bin -p
tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin
部署CNI网络:
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
sed -i -r "s#quay.io/coreos/flannel:.*-amd64#lizhenliang/flannel:v0.12.0-amd64#g" kube-flannel.yml
默认镜像地址无法访问, 修改为docker hub镜像仓库。
kubectl apply -f kube-flannel.yml
kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
kube-flannel-ds-amd64-zkt9h 1/1 Running 0 101s
#查看pod状态
kubectl describe pods -n kube-system
5.6 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
5.7 新增加Worker Node
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192.168.31.72/192.168.31.73
scp -r /opt/kubernetes root@192.168.31.72:/opt/
scp -r /opt/kubernetes root@192.168.31.73:/opt/
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.31.72:/usr/lib/systemd/system
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.31.73:/usr/lib/systemd/system
scp -r /opt/cni/ root@192.168.31.72:/opt/
scp -r /opt/cni/ root@192.168.31.73:/opt/
2.删除kubelet证书和kubeconfig文件
rm /opt/kubernetes/cfg/kubelet.kubeconfig
rm -f /opt/kubernetes/ssl/kubelet*
注:这几个文件是证书申请审批后自动生成的, 每个Node不同 , 必须删除重新生成
3.修改主机名
vim /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node1
vim /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node2
4.启动并设置开机自动
systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet
systemctl start kube-proxy
systemctl enable kube-proxy
5.在Master上批准新Node kubelet证书申请
kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-AjchWd-e7ORKHpi6kwm17aIi7SWfao6S-UofT_o-2p8 2m35s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
node-csr-RrAbmArhPhH9U4xm7oMqPY4oauQybeHvub9VMAj9VoM 70m kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Approved,Issued
#node1
kubectl certificate approve node-csr-AjchWd-e7ORKHpi6kwm17aIi7SWfao6S-UofT_o-2p8
kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-AjchWd-e7ORKHpi6kwm17aIi7SWfao6S-UofT_o-2p8 7m34s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Approved,Issued
node-csr-RrAbmArhPhH9U4xm7oMqPY4oauQybeHvub9VMAj9VoM 75m kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Approved,Issued
node-csr-Tmx2_KM58-Nh4kU_ii3Fwu_q8HCgs_xpZD8HGASFB_g 12s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
#node2
kubectl certificate approve node-csr-Tmx2_KM58-Nh4kU_ii3Fwu_q8HCgs_xpZD8HGASFB_g
kubectl delete node k8s-master
kubectl delete node k8s-node1
kubectl delete node k8s-node2
六、部署Dashboard和CoreDNS
6.1 部署Dashboard
https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta8/aio/deploy/recommended.yaml
默认Dashboard只能集群内部访问, 修改Service为NodePort类型, 暴露到外部
vim recommended.yaml
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kubernetes-dashboard
spec:
ports:
- port: 443
targetPort: 8443
nodePort: 30001
type: NodePort
selector:
k8s-app: kubernetes-dashboard
kubectl apply -f recommended.yaml
kubectl get pods,svc -n kubernetes-dashboard
NAME READY STATUS RESTARTS AGE
pod/dashboard-metrics-scraper-694557449d-bxvcg 1/1 Running 0 114s
pod/kubernetes-dashboard-9774cc786-m9q8g 1/1 Running 0 114s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/dashboard-metrics-scraper ClusterIP 10.0.0.48 <none> 8000/TCP 114s
service/kubernetes-dashboard NodePort 10.0.0.122 <none> 443:30001/TCP 56s
访问地址: https://NodeIP:30001
创建service account并绑定默认cluster-admin管理员集群角色:
kubectl create serviceaccount dashboard-admin -n kube-system
kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')
使用输出的token登录Dashboard
6.2 汉化为中文
Dashboard 的页面都已经被汉化了 , 当前支持英文, 中文简体等,根据浏览器的语言自动切换的 。 如果想要强制设置dashboard中显示的语言 , 需要在dashboard 的Deployment yaml配置中增加如下配置:
英文
env:
name: ACCEPT_LANGUAGE
value: english
中文
env:
name: ACCEPT_LANGUAGE
value: zh
这种方式是强制容器显示内容为中文, 经过验证有效(但是可能不全)
6.2部署CoreDNS
CoreDNS用于集群内部Service名称解析
kubectl apply -f coredns.yaml
kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-7b5f8b68d5-jdfmf 1/1 Running 0 116s
coredns-7b5f8b68d5-xqhxw 1/1 Running 0 116s
kube-flannel-ds-amd64-b2rhq 1/1 Running 0 10h
kube-flannel-ds-amd64-g5dnz 1/1 Running 0 9h
kube-flannel-ds-amd64-ltjs6 1/1 Running 0 9h
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
为以上内容 , 表示coredns部署正常
七、高可用架构(扩容多个Master架构)
kubetes作为容器集群系统, 通过健康检查+重启策略实现了Pod故障自我修复能力 , 通过调度算法实现将Pod分布式部署, 并保持预期副本数, 根据Node失效状态自动在其他Node拉起Pod, 实现应用层的高可用性。
针对kubernnetes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个节点组件集群实现高可用 ,本节点将对Master节点高可用进行说明和实施部署 。
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监控工作状态 。 如果Master节点故障, 将无法使用kubectl工具或者API做任何集群管理 。
Master节点主要有三个服务kube-apiserver、kube-controller-manager和kube-scheduler,其中kube-controller-manager和kube-scheduler组件自身通过选择机制已经实现了高可用, 所以Master高可用主要针对kube-apiserver组件,而该组件是以http API提供服务 , 因此对他高可用与Web服务器类似, 增加负载均衡对其负载均衡即可 , 并且可水平扩容 。
多个Master架构图
7.1 安装Docker
部署Master2 node(192.168.31.74)
Master2与已部署的master1所以操作一致 。 所以我们只需要将master 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
1.创建etcd证书目录
在master2创建etcd证书目录
mkdir -p /opt/etcd/ssl
2.拷贝文件(master1操作)
拷贝master1 上所有k8s文件和etcd 证书到master2
scp -r /opt/kubernetes root@192.168.31.74:/opt
scp -r /opt/cni/ root@192.168.31.72:/opt
scp -r /opt/cni/ root@192.168.31.74:/opt
scp -r /opt/etcd/ssl root@192.168.31.74:/opt/etcd
scp /usr/lib/systemd/system/kube* root@192.168.31.74:/usr/lib/systemd/system
scp /usr/bin/kubectl root@192.168.31.74:/usr/bin/
3.删除证书文件
删除kubelet证书和kubernetes文件:
rm -f /opt/kubernetes/cfg/kubelet*
rm -f /opt/kubernetes/ssl/kubelet*
4.修改配置文件IP和主机名
修改apiserver,kubelet和kube-proxy配置文件为本地IP
vi /opt/kubernetes/cfg/kube-apiserver.conf
...
--bind-address=192.168.31.74 \
--advertise-address=192.168.31.74 \
...
vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-master2
vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-master2
5.启动设置开机启动
systemctl daemon-reload
systemctl start kube-apiserver
systemctl start kube-controller-manager
systemctl start kube-scheduler
systemctl start kubelet
systemctl start kube-proxy
systemctl enable kube-apiserver
systemctl enable kube-controller-manager
systemctl enable kube-scheduler
systemctl enable kubelet
systemctl enable kube-proxy
6.查看集群状态
kubectl get cs
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-0 Healthy {"health":"true"}
etcd-2 Healthy {"health":"true"}
etcd-1 Healthy {"health":"true"}
7.批准kubelet证书申请
kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-jvn3j3erGwwkf7HctNYT2aEsb1HA43465ixW1Evo-Zk 39s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
kubectl certificate approve node-csr-jvn3j3erGwwkf7HctNYT2aEsb1HA43465ixW1Evo-Zk
7.3 部署nginx负载均衡
Kube-apiserver高可用架构图:
-
nginx是一个主流web服务器和反向代理服务器, 这里用四层实现对apiserver实现负载均衡。
-
Keepalived 是一个主流高可用软件, 基于VIP绑定实现服务器双机热备, 在上述拓扑中,keepalived主要根据Nginx运行状态判断是否需要故障转移(偏移VIP),例如当Nginx主节点挂掉, VIP会自动绑定在Nginx备节点, 从而保证VIP一直可用, 实现Nginx高可用。
1.安装软件包(主、备)
yum install epel-release -y
yum install nginx keepalived -y
2.Nginx配置文件(主、备一样)
cat > /etc/nginx/nginx.conf << "EOF"
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
include /usr/share/nginx/modules/*.conf;
events {
worker_connections 1024;
}
# 四层负载均衡,为两台Master apiserver组件提供负载均衡
stream {
log_format main '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent';
access_log /var/log/nginx/k8s-access.log main;
upstream k8s-apiserver {
server 192.168.31.71:6443; # Master1 APISERVER IP:PORT
server 192.168.31.74:6443; # Master2 APISERVER IP:PORT
}
server {
listen 6444;
proxy_pass k8s-apiserver;
}
}
http {
log_format main '$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
yum安装的ngixn其实是带stream模块的,但默认没有加载,需要在nginx.conf首行加入:
load_module /usr/lib64/nginx/modules/ngx_stream_module.so;
3.keepalived配置文件(nginx master)
cat > /etc/keepalived/keepalived.conf << EOF
global_defs {
notification_email {
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id NGINX_MASTER
}
vrrp_script check_nginx {
script "/etc/keepalived/check_nginx.sh"
interval 2
weight -20
}
vrrp_instance VI_1 {
state MASTER
interface ens33 # 修改为实际网卡名
virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的
priority 100 # 优先级,备服务器设置 90
advert_int 1 # 指定VRRP 心跳包通告间隔时间,默认1秒
authentication {
auth_type PASS
auth_pass 1111
}
# 虚拟IP
virtual_ipaddress {
192.168.31.88/24
}
track_script {
check_nginx
}
}
EOF
- vrrp_script:指定检查nginx工作状态脚本(根据nginx状态判断是否故障转移)
- virtual_ipaddress:虚拟IP(VIP)
检查nginx状态脚本:
cat > /etc/keepalived/check_nginx.sh << "EOF"
#!/bin/bash
count=$(ps -ef |grep nginx |egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
exit 1
else
exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh
4.keepalived配置文件(Nginx Backup)
cat > /etc/keepalived/keepalived.conf << EOF
global_defs {
notification_email {
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id NGINX_BACKUP
}
vrrp_script check_nginx {
script "/etc/keepalived/check_nginx.sh"
}
vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.31.88/24
}
track_script {
check_nginx
}
}
EOF
上述配置文件中检查nginx运行状态脚本:
cat > /etc/keepalived/check_nginx.sh << "EOF"
#!/bin/bash
count=$(ps -ef |grep nginx |egrep -cv "grep|$$")
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。
5.启动并设置开机启动
systemctl daemon-reload
systemctl start nginx
systemctl start keepalived
systemctl enable nginx
systemctl enable keepalived
FAQ : 如果nginx 启动报错 , 一般是没有stream 模块
操作步骤
1.检查nginx版本
nginx -v
2.检查nginx编译参数
nginx -V
3.下载与之对应的nginx tar 或模块并解压
wget http://nginx.org/download/nginx-1.20.1.tar.gz
4.编译nginx
#./configure 上面的编译命令 --add-module=/usr/local/ #其他模块
./configure 上面的编译命令 --with-stream
make
make install
5.拷贝编译后的可执行文件
依赖
yum -y install libxml2 libxml2-dev libxslt-devel
yum -y install gd-devel
yum -y install perl-devel perl-ExtUtils-Embed
yum -y install GeoIP GeoIP-devel GeoIP-data
yum -y install pcre-devel
yum -y install openssl openssl-devel
6. 查看keepalived工作状态
ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 00:0c:29:04:f7:2c brd ff:ff:ff:ff:ff:ff
inet 192.168.31.80/24 brd 192.168.31.255 scope global noprefixroute ens33
valid_lft forever preferred_lft forever
inet 192.168.31.88/24 scope global secondary ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe04:f72c/64 scope link
valid_lft forever preferred_lft forever
可以看到,在ens33网卡绑定了192.168.31.88 虚拟IP,说明工作正常。
7. Nginx+Keepalived高可用测试
关闭主节点Nginx,测试VIP是否漂移到备节点服务器。
在Nginx Master执行 pkill nginx
在Nginx Backup,ip addr命令查看已成功绑定VIP。
8. 访问负载均衡器测试
找K8s集群中任意一个节点,使用curl查看K8s版本测试,使用VIP访问:
curl -k https://192.168.31.88:6443/version
{
"major": "1",
"minor": "18",
"gitVersion": "v1.18.3",
"gitCommit": "2e7996e3e2712684bc73f0dec0200d64eec7fe40",
"gitTreeState": "clean",
"buildDate": "2020-05-20T12:43:34Z",
"goVersion": "go1.13.9",
"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:
到此还没结束,还有下面最关键的一步。
7.4 修改所有Worker Node连接LB VIP
试想下,虽然我们增加了Master2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Node组件连接都还是Master1,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Node组件配置文件,由原来192.168.31.71修改为192.168.31.88(VIP):
角色 | IP |
---|---|
k8s-master1 | 192.168.31.71 |
k8s-master2 | 192.168.31.74 |
k8s-node1 | 192.168.31.72 |
k8s-node2 | 192.168.31.73 |
也就是通过kubectl get node命令查看到的节点。
在上述所有Worker Node执行:
sed -i 's#192.168.31.71:6443#192.168.31.88:6444#' /opt/kubernetes/cfg/*
systemctl restart kubelet
systemctl restart kube-proxy
检查节点状态:
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master Ready <none> 34h v1.18.3
k8s-master2 Ready <none> 101m v1.18.3
k8s-node1 Ready <none> 33h v1.18.3
k8s-node2 Ready <none> 33h v1.18.3
至此,一套完整的 Kubernetes 高可用集群就部署完成了!
PS: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(内网就行,还免费~),架构与上面一样,直接负载均衡多台Master kube-apiserver即可!
7.5 配置使用ipvs代理
前置条件
modprobe br_netfilter
cat > /etc/sysconfig/modules/ipvs.modules << EOF
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- ip_vs_nq
modprobe -- ip_vs_seq
modprobe -- nf_conntrack_ipv4
EOF
chmod 755 /etc/sysconfig/modules/ipvs.modules && \
bash /etc/sysconfig/modules/ipvs.modules &&\
lsmod | grep -e ip_vs -e nf_conntrack_ipv4
更改ipvs配置文件
cat > /opt/kubernetes/cfg/kube-proxy.conf << EOF
KUBE_PROXY_OPTS="--logtostderr=false \\
--masquerade-all=true \\
--proxy-mode=ipvs \\
--ipvs-min-sync-period=5s \\
--ipvs-sync-period=5s \\
--ipvs-scheduler=rr \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--config=/opt/kubernetes/cfg/kube-proxy-config.yml "
EOF
更改配置参数文件 mode 为ipvs
cat > /opt/kubernetes/cfg/kube-proxy-config.yml << EOF
kind: KubeProxyConfiguration
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 0.0.0.0
metricsBindAddress: 0.0.0.0:10249
clientConnection:
kubeconfig: /opt/kubernetes/cfg/kube-proxy.kubeconfig
hostnameOverride: k8s-master
clusterCIDR: 10.0.0.0/24
mode: "ipvs"
EOF
FAQ
1.在kube-proxy日志里面有很多报错
E0813 10:47:18.983433 454071 proxier.go:722] conntrack return with error: error looking for path of conntrack: exec: "conntrack": executable file not found in $PATH
E0813 10:47:18.983492 454071 proxier.go:722] conntrack return with error: error looking for path of conntrack: exec: "conntrack": executable file not found in $PATH
E0813 10:47:18.983513 454071 proxier.go:722] conntrack return with error: error looking for path of conntrack: exec: "conntrack": executable file not found in $PATH
很容易理解,这个就是conntrack没有安装,那么这个conntrack是干嘛的很多人可能不太理解,它是一个用户态的命令,用于控制内核中ip_conntrack模块的,该模块是用于处理链路追踪的工具。就是iptables和netfilter的关系。
简单介绍一下ip_conntrack模块,数据包(a -> b)经过网关,发生了SNAT,地址信息成为了(m -> b),虽然发生了nat,(a -> b)和(m -> b)应该是属于同一个数据流conntrack的,ip_conntrack需要作记录,以便将两个流绑定在一起,数据从a到b的方向在网关处成了由m到b的方向,属于一个方向,都是源到目的,发生了SNAT后,数据就可以出去了,既然数据离开了网关,我们也就不必关心它了,我们关心的是从b发出的回应a数据到达网关后如何将之绑定到流conntrack,数据回来后由于发生过snat流标示显然是(b -> m),于是ip_conntrack需要将(b-m)也绑定到conntrack,这样才能将数据返回。由于ip_conntrack帮助,可以将两个连接捆绑到一起,通过ip_conntrack来帮助netfilter进行流量转发。
回到kubernetes的问题上面,proxy在删除UDP的service时候也需要清除这些ip_conntrack连接。否则还会还会把流量导入的废弃的pod上面。
修复需要安装conntrack-tools
yum install conntrack-tools