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k3s高可用部署

说明:

# 影响k3s 高可用的阻力就是所有master 节点的证书统一,解决方案是先成功部署一个master 节点然后把节点生成
证书复制到其它master节点包括token,同时使用etcd 作为数据库

环境说明:

# 操作系统:centos8  1905
#k3s版本:v0.9.1
#etcd 版本: v3.4.1
# etcd 服务器IP:192.168.30.50,192.168.30.51,192.168.30.52 
# 安装目录:/apps/业务
# 服务器节点IP:192.168.30.50,192.168.30.51,192.168.30.52 node节点192.168.30.53,vip 节点:192.168.30.59
# k3s 集群域名: cluster.local
# k3s api 接口域名:api.k3s.tyong.com
# k3s cluster-cidr:10.48.0.0/12
# k3s service-cidr:10.64.0.0/16
#k3s cluster-DNS:10.64.0.2

二进制准备:

# 所有节点
# 下载etcd 二进制
wget https://github.com/etcd-io/etcd/releases/download/v3.4.1/etcd-v3.4.1-linux-amd64.tar.gz
# 解压二进制文件
tar -xvf etcd-v3.4.1-linux-amd64.tar.gz
# 创建etcd 运行目录
mkdir -p /apps/etcd/{bin,conf,ssl,data}
# 复制二进制到运行目录
cd etcd-v3.4.1-linux-amd64
mv mv etcd* /apps/etcd/bin
# 下载K3S
wget https://github.com/rancher/k3s/releases/download/v0.9.1/k3s
# 可执行权限
chmod +x k3s
# 复制k3s 到运行目录
mv k3s /usr/local/bin/
# 创建软链方便使用
cd /usr/local/bin/
ln -sf k3s kubectl
ln -sf k3s crictl
ln -sf k3s ctr
# 习惯修改
vi  ~/.bashrc
alias docker='k3s crictl'
. ~/.bashrc

对系统做简单优化

# 设置 system.conf
cat >> /etc/systemd/system.conf << EOF
DefaultLimitMEMLOCK=infinity
DefaultLimitCORE=infinity
DefaultCPUAccounting=yes
DefaultMemoryAccounting=yes
DefaultLimitNOFILE=1024000
DefaultLimitNPROC=1024000
EOF
# 设置关闭防火墙及SELINUX
sed -i 's/SELINUX=.*/SELINUX=disabled/g' /etc/selinux/config 
systemctl stop firewalld && systemctl disable firewalld
setenforce 0
# 关闭Swap
swapoff -a && sysctl -w vm.swappiness=0
vi /etc/fstab
#/dev/mapper/centos-swap swap swap defaults 0 0
# 设置 sysctl.conf 内核配置
true > /etc/sysctl.conf
cat >> /etc/sysctl.conf << EOF
 net.ipv4.ip_forward = 1
 net.ipv4.conf.default.rp_filter = 1
 net.ipv4.conf.default.accept_source_route = 0
 kernel.sysrq = 0
 kernel.core_uses_pid = 1
 net.ipv4.tcp_syncookies = 1
 fs.file-max = 1024000
 fs.nr_open = 1024000
 vm.swappiness = 0
 vm.max_map_count = 2048000
 vm.overcommit_memory = 1
 kernel.sem =5010 641280 5010 128
 kernel.pid_max = 4194303
 kernel.msgmnb = 65536
 kernel.msgmax = 65536
 kernel.shmmax = 68719476736
 kernel.shmall = 4294967296
 net.ipv4.tcp_max_tw_buckets = 6000
 net.ipv4.tcp_sack = 1
 net.ipv4.tcp_window_scaling = 1
 net.ipv4.tcp_mem = 786432 1697152 1945728
 net.ipv4.tcp_rmem = 4096 87380 16777216
 net.ipv4.tcp_wmem = 4096 65536 16777216
 net.core.wmem_default = 8388608
 net.core.rmem_default = 8388608
 net.core.rmem_max = 16777216
 net.core.wmem_max = 16777216
 net.core.netdev_max_backlog = 2048000
 net.core.somaxconn = 65535
 net.ipv4.tcp_max_orphans = 3276800
 net.ipv4.tcp_max_syn_backlog = 2048000
 net.ipv4.tcp_mem = 94500000 915000000 927000000
 net.ipv4.tcp_fin_timeout = 1
 net.ipv4.tcp_keepalive_time = 600
 net.ipv4.tcp_keepalive_probes = 10
 net.ipv4.tcp_keepalive_intvl = 30
 net.ipv4.ip_local_port_range = 1024 65535
 net.ipv4.neigh.default.gc_stale_time=120
 net.ipv4.conf.default.rp_filter=0
 net.ipv4.conf.all.rp_filter=0
 net.ipv4.conf.all.arp_announce=2
 net.ipv4.conf.lo.arp_announce=2
 sunrpc.tcp_slot_table_entries=256
EOF
/sbin/sysctl -p
# 设置limits.conf
cat >> /etc/security/limits.conf << EOF
 *           soft   nproc       1024000
 *           hard   nproc       1024000
 *           soft   nofile      1024000
 *           hard   nofile      1024000
 *           soft   core        1024000
 *           hard   core        1024000
 ######big mem ########
 #*           hard    memlock    unlimited  
 #*           soft    memlock    unlimited
EOF
# centos8 已经取消20-nproc.conf 文件
# 设置NetworkManager 配置静态IP
vi /etc/sysconfig/network-scripts/ifcfg-eth0
TYPE=Ethernet
BOOTPROTO=static
DEFROUTE=yes
NAME=eth0
DEVICE=eth0
ONBOOT=yes
IPADDR="192.168.30.50"
PREFIX="24"
GATEWAY="192.168.30.1"
DNS1="192.168.30.10"
# 生效配置 
nmcli c reload
# centos8 已经取消network 访问管理网络 其它节点参考

部署etcd

# 操作节点:192.168.30.50
# 部署go 环境变量,当然也可以在工作机器部署
#安装及配置CFSSL
yum install go
vi ~/.bash_profile
GOBIN=/root/go/bin/
PATH=$PATH:$GOBIN:$HOME/bin
export PATH
go get  github.com/cloudflare/cfssl/cmd/cfssl
go get  github.com/cloudflare/cfssl/cmd/cfssljson
# 创建etcdCA 证书配置
mkdir -p /apps/work/k8s/cfssl/ && \
cat << EOF | tee /apps/work/k8s/cfssl/ca-config.json
{
"signing": {
"default": {
"expiry": "87600h"
},
"profiles": {
"kubernetes": {
"usages": [
"signing",
"key encipherment",
"server auth",
"client auth"
],
"expiry": "87600h"
}
}
}
}
EOF
---------------------------------------------------------------------
mkdir -p /apps/work/k8s/cfssl/etcd
cat << EOF | tee /apps/work/k8s/cfssl/etcd/etcd-ca-csr.json
{
"CN": "etcd",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "GuangDong",
"L": "GuangZhou",
"O": "cluster",
"OU": "ETCD"
}
]
}
EOF
# 生成ca证书
----------------------------------------------------------------------
cfssl gencert -initca \
/apps/work/k8s/cfssl/etcd/etcd-ca-csr.json | \
cfssljson -bare ./etcd-ca
# 创建etcd server 证书配置
-----------------------------------------------------------------------------
export ETCD_SERVER_IPS=" \
\"192.168.30.50\", \
\"192.168.30.51\", \
\"192.168.30.52\" \
" && \
export ETCD_SERVER_HOSTNAMES=" \
\"k3s-001\", \
\"k3s-002\", \
\"k3s-003\" \
" && \
cat << EOF | tee /apps/work/k8s/cfssl/etcd/etcd_server.json
{
"CN": "etcd",
"hosts": [
"127.0.0.1",
${ETCD_SERVER_IPS},
${ETCD_SERVER_HOSTNAMES}
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "GuangDong",
"L": "GuangZhou",
"O": "cluster",
"OU": "ETCD"
}
]
}
EOF
# 生成etcd server 证书
-----------------------------------------------------------------------------
cfssl gencert \
-ca=./etcd-ca.pem \
-ca-key=./etcd-ca-key.pem \
-config=/apps/work/k8s/cfssl/ca-config.json \
-profile=kubernetes \
/apps/work/k8s/cfssl/etcd/etcd_server.json | \
cfssljson -bare ./etcd_server
# 创建member证书 k3s-01 节点
--------------------------------------------------------------------------------------
export ETCD_MEMBER_1_IP=" \
    \"192.168.30.50\" \
" && \
export ETCD_MEMBER_1_HOSTNAMES="k3s-001\
" && \
cat << EOF | tee /apps/work/k8s/cfssl/etcd/${ETCD_MEMBER_1_HOSTNAMES}.json
{
  "CN": "etcd",
  "hosts": [
    "127.0.0.1",
    ${ETCD_MEMBER_1_IP},
    "${ETCD_MEMBER_1_HOSTNAMES}"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "GuangDong",
      "L": "GuangZhou",
      "O": "cluster",
      "OU": "ETCD"
    }
  ]
}
EOF
# 生成k3s-01 节点证书
-----------------------------------------------------------------------------
cfssl gencert \
    -ca=./etcd-ca.pem \
    -ca-key=./etcd-ca-key.pem \
    -config=/apps/work/k8s/cfssl/ca-config.json \
    -profile=kubernetes \
    /apps/work/k8s/cfssl/etcd/${ETCD_MEMBER_1_HOSTNAMES}.json | \
    cfssljson -bare ./etcd_member_${ETCD_MEMBER_1_HOSTNAMES}
# 创建生成k3s-02 节点配置
-----------------------------------------------------------------------------
export ETCD_MEMBER_2_IP=" \
    \"192.168.30.51\" \
" && \
export ETCD_MEMBER_2_HOSTNAMES="k3s-002\
" && \
cat << EOF | tee /apps/work/k8s/cfssl/etcd/${ETCD_MEMBER_2_HOSTNAMES}.json
{
  "CN": "etcd",
  "hosts": [
    "127.0.0.1",
    ${ETCD_MEMBER_2_IP},
    "${ETCD_MEMBER_2_HOSTNAMES}"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "GuangDong",
      "L": "GuangZhou",
      "O": "cluster",
      "OU": "ETCD"
    }
  ]
}
EOF  
# 生成k3s-02 节点证书
--------------------------------------------------------------------------
cfssl gencert \
    -ca=./etcd-ca.pem \
    -ca-key=./etcd-ca-key.pem \
    -config=/apps/work/k8s/cfssl/ca-config.json \
    -profile=kubernetes \
    /apps/work/k8s/cfssl/etcd/${ETCD_MEMBER_2_HOSTNAMES}.json | \
    cfssljson -bare ./etcd_member_${ETCD_MEMBER_2_HOSTNAMES}
# 创建k3s-03 节点配置
--------------------------------------------------------------------------    
export ETCD_MEMBER_3_IP=" \
    \"192.168.30.52\" \
" && \
export ETCD_MEMBER_3_HOSTNAMES="k3s-003\
" && \
cat << EOF | tee /apps/work/k8s/cfssl/etcd/${ETCD_MEMBER_3_HOSTNAMES}.json
{
  "CN": "etcd",
  "hosts": [
    "127.0.0.1",
    ${ETCD_MEMBER_3_IP},
    "${ETCD_MEMBER_3_HOSTNAMES}"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "GuangDong",
      "L": "GuangZhou",
      "O": "cluster",
      "OU": "ETCD"
    }
  ]
}
EOF
#  生成k3s-03 节点证书
------------------------------------------------------------------------------
cfssl gencert \
    -ca=./etcd-ca.pem \
    -ca-key=./etcd-ca-key.pem \
    -config=/apps/work/k8s/cfssl/ca-config.json \
    -profile=kubernetes \
    /apps/work/k8s/cfssl/etcd/${ETCD_MEMBER_3_HOSTNAMES}.json | \
    cfssljson -bare ./etcd_member_${ETCD_MEMBER_3_HOSTNAMES}
# 创建etcd client 证书
-----------------------------------------------------------------------------------    
cat << EOF | tee /apps/work/k8s/cfssl/etcd/etcd_client.json
{
"CN": "client",
"hosts": [""],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "GuangDong",
"L": "GuangZhou",
"O": "cluster",
"OU": "ETCD"
}
]
}
EOF
# 生成etcd client 证书
--------------------------------------------------------------
cfssl gencert \
-ca=./etcd-ca.pem \
-ca-key=./etcd-ca-key.pem \
-config=/apps/work/k8s/cfssl/ca-config.json \
-profile=kubernetes \
/apps/work/k8s/cfssl/etcd/etcd_client.json | \
cfssljson -bare ./etcd_client
# 配置etcd01 启动文件
vi /apps/etcd/conf/etcd
------------------------------------------------------------------------------------------------------------------------------------------------
ETCD_OPTS="--name=k3s-001 \
           --data-dir=/apps/etcd/data/default.etcd \
           --listen-peer-urls=https://192.168.30.50:2380 \
           --listen-client-urls=https://192.168.30.50:2379,https://127.0.0.1:2379 \
           --advertise-client-urls=https://192.168.30.50:2379 \
           --initial-advertise-peer-urls=https://192.168.30.50:2380 \
           --initial-cluster=k3s-001=https://192.168.30.50:2380,k3s-002=https://192.168.30.51:2380,k3s-003=https://192.168.30.52:2380 \
           --initial-cluster-token=k3s-001=https://192.168.30.50:2380,k3s-002=https://192.168.30.51:2380,k3s-003=https://192.168.30.52:2380 \
           --initial-cluster-state=new \
           --heartbeat-interval=6000 \
           --election-timeout=30000 \
           --snapshot-count=5000 \
           --auto-compaction-retention=1 \
           --max-request-bytes=33554432 \
           --quota-backend-bytes=17179869184 \
           --trusted-ca-file=/apps/etcd/ssl/etcd-ca.pem \
           --cert-file=/apps/etcd/ssl/etcd_server.pem \
           --key-file=/apps/etcd/ssl/etcd_server-key.pem \
           --peer-cert-file=/apps/etcd/ssl/etcd_member_k3s-001.pem \
           --peer-key-file=/apps/etcd/ssl/etcd_member_k3s-001-key.pem \
           --peer-client-cert-auth \
           --peer-trusted-ca-file=/apps/etcd/ssl/etcd-ca.pem"
# 创建etcd 启动文件
------------------------------------------------------------------------
vi /usr/lib/systemd/system/etcd.service
---------------------------------------------------------------------
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
LimitNOFILE=1024000
LimitNPROC=1024000
LimitCORE=infinity
LimitMEMLOCK=infinity
User=etcd
Group=etcd

EnvironmentFile=-/apps/etcd/conf/etcd
ExecStart=/apps/etcd/bin/etcd $ETCD_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target
-----------------------------------------------------------------
# 创建etcd 用户
useradd etcd -s /sbin/nologin -M
-----------------------------------------------------------------
# 给予/apps/etcd 目录etcd用户权限
chown -R etcd:etcd /apps/etcd
----------------------------------------------------------------
# k3s-02 节点创建etcd 用户
useradd etcd -s /sbin/nologin -M
-----------------------------------------------------------------
# k3s-03 节点创建etcd 用户
useradd etcd -s /sbin/nologin -M
-----------------------------------------------------------------
# 分发文件到  k3s-02  k3s-03 节点
scp -r /apps/etcd 192.168.30.51:/apps/
scp -r /apps/etcd 192.168.30.52:/apps/
# 分发启动文件到 k3s-02  k3s-03 节点
scp  /usr/lib/systemd/system/etcd.service  192.168.30.51: /usr/lib/systemd/system/etcd.service
scp  /usr/lib/systemd/system/etcd.service  192.168.30.52: /usr/lib/systemd/system/etcd.service
# 修改k3s-02 /apps/etcd/conf/etcd 文件
vi /apps/etcd/conf/etcd
--------------------------------------------------------------------------
ETCD_OPTS="--name=k3s-002 \
           --data-dir=/apps/etcd/data/default.etcd \
           --listen-peer-urls=https://192.168.30.51:2380 \
           --listen-client-urls=https://192.168.30.51:2379,https://127.0.0.1:2379 \
           --advertise-client-urls=https://192.168.30.51:2379 \
           --initial-advertise-peer-urls=https://192.168.30.51:2380 \
           --initial-cluster=k3s-001=https://192.168.30.50:2380,k3s-002=https://192.168.30.51:2380,k3s-003=https://192.168.30.52:2380 \
           --initial-cluster-token=k3s-001=https://192.168.30.50:2380,k3s-002=https://192.168.30.51:2380,k3s-003=https://192.168.30.52:2380 \
           --initial-cluster-state=new \
           --heartbeat-interval=6000 \
           --election-timeout=30000 \
           --snapshot-count=5000 \
           --auto-compaction-retention=1 \
           --max-request-bytes=33554432 \
           --quota-backend-bytes=17179869184 \
           --trusted-ca-file=/apps/etcd/ssl/etcd-ca.pem \
           --cert-file=/apps/etcd/ssl/etcd_server.pem \
           --key-file=/apps/etcd/ssl/etcd_server-key.pem \
           --peer-cert-file=/apps/etcd/ssl/etcd_member_k3s-002.pem \
           --peer-key-file=/apps/etcd/ssl/etcd_member_k3s-002-key.pem \
           --peer-client-cert-auth \
           --peer-trusted-ca-file=/apps/etcd/ssl/etcd-ca.pem"
# 修改 修改k3s-03 /apps/etcd/conf/etcd 文件
----------------------------------------------------------------------------
vi /apps/etcd/conf/etcd
----------------------------------------------------------------------------
ETCD_OPTS="--name=k3s-003 \
           --data-dir=/apps/etcd/data/default.etcd \
           --listen-peer-urls=https://192.168.30.52:2380 \
           --listen-client-urls=https://192.168.30.52:2379,https://127.0.0.1:2379 \
           --advertise-client-urls=https://192.168.30.52:2379 \
           --initial-advertise-peer-urls=https://192.168.30.52:2380 \
           --initial-cluster=k3s-001=https://192.168.30.50:2380,k3s-002=https://192.168.30.51:2380,k3s-003=https://192.168.30.52:2380 \
           --initial-cluster-token=k3s-001=https://192.168.30.50:2380,k3s-002=https://192.168.30.51:2380,k3s-003=https://192.168.30.52:2380 \
           --initial-cluster-state=new \
           --heartbeat-interval=6000 \
           --election-timeout=30000 \
           --snapshot-count=5000 \
           --auto-compaction-retention=1 \
           --max-request-bytes=33554432 \
           --quota-backend-bytes=17179869184 \
           --trusted-ca-file=/apps/etcd/ssl/etcd-ca.pem \
           --cert-file=/apps/etcd/ssl/etcd_server.pem \
           --key-file=/apps/etcd/ssl/etcd_server-key.pem \
           --peer-cert-file=/apps/etcd/ssl/etcd_member_k3s-003.pem \
           --peer-key-file=/apps/etcd/ssl/etcd_member_k3s-003-key.pem \
           --peer-client-cert-auth \
           --peer-trusted-ca-file=/apps/etcd/ssl/etcd-ca.pem"
-----------------------------------------------------------------------------
# 启动etcd 集群 k3s-01 k3s-02 k3s-03
systemctl start etcd
# 设置开机启动  k3s-01 k3s-02 k3s-03
systemctl enable etcd
----------------------------------------------------------------------------------
# 验证K3S 是否正常
vi  /etc/profile
export ETCDCTL_API=3
export ENDPOINTS=https://192.168.30.50:2379,https://192.168.30.51:2379,https://192.168.30.52:2379
# 生效环境变量 
.  /etc/profile
# 配置命令别名 alias
vi  /root/.bashrc
alias etcdctl='/apps/etcd/bin/etcdctl   --endpoints=${ENDPOINTS}   --cacert=/apps/etcd/ssl/etcd-ca.pem'
# 生效
. /root/.bashrc
# 验证集群
etcdctl  member list
etcdctl endpoint status
https://192.168.30.50:2379, 7b98f2ed4d780753, 3.3.12, 290 MB, true, 37886, 82704406
https://192.168.30.51:2379, 47fa5d2eb78a7751, 3.3.12, 289 MB, false, 37886, 82704408
https://192.168.30.52:2379, 76c6cd81499cf7ba, 3.3.12, 289 MB, false, 37886, 82704433
# etcd 集群正常

k3s master 节点部署

# 添加一个虚拟IP
ip addr add 192.168.30.59/24 dev eth0
# 安装依赖
--------------------------------------------
dnf install epel-release
---------------------------
dnf install   dnf-utils ipvsadm telnet wget net-tools conntrack ipset jq iptables curl sysstat libseccomp socat nfs-utils fuse fuse-devel
------------------------------------------------
# centos 8 不能自动加载ipvs 创建开机加载
cat << EOF > /etc/sysconfig/modules/ipvs.modules
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF
# /etc/sysconfig/modules/ipvs.modules 可执行权限
chmod +x /etc/sysconfig/modules/ipvs.modules
# 执行 /etc/sysconfig/modules/ipvs.modules
/etc/sysconfig/modules/ipvs.modules
-----------------------------------
mkdir -p /apps/k3s
# 操作节点k3s-01 节点
# 创建k3s env
vi /etc/sysconfig/k3s.env
----------------------------------------------
K3S_SERVER_OPTS='--data-dir=/apps/k3s \
         --no-deploy=traefik \
         --no-deploy=coredns \
         --no-deploy=servicelb \
         --no-deploy=helm-install-traefik \
         --kube-proxy-arg="proxy-mode=ipvs" \
         --kube-proxy-arg="masquerade-all=true" \
         --cluster-cidr="10.48.0.0/12" \
         --service-cidr="10.64.0.0/16" \
         --cluster-dns="10.64.0.2" \
         --cluster-domain="cluster.local" \
         --tls-san="192.168.30.51" \
         --tls-san="192.168.30.52" \
         --tls-san="192.168.30.59" \
         --tls-san="192.168.30.50" \
         --tls-san="api.k3s.tyong.com" \
         --tls-san="kubernetes" \
         --tls-san="kubernetes.default" \
         --tls-san="kubernetes.default.svc" \
         --tls-san="kubernetes.default.svc.cluster.local" \
         --storage-endpoint=etcd \
         --kube-apiserver-arg="etcd-cafile=/apps/etcd/ssl/etcd-ca.pem" \
         --kube-apiserver-arg="etcd-certfile=/apps/etcd/ssl/etcd_client.pem" \
         --kube-apiserver-arg="etcd-keyfile=/apps/etcd/ssl/etcd_client-key.pem" \
         --kube-apiserver-arg="etcd-prefix=/registry" \
         --kube-apiserver-arg="etcd-servers=https://192.168.30.50:2379,https://192.168.30.51:2379,https://192.168.30.52:2379" \
         --kube-apiserver-arg="runtime-config=api/all=true" \
         --kube-apiserver-arg="enable-admission-plugins=DefaultStorageClass,DefaultTolerationSeconds,LimitRanger,NamespaceExists,NamespaceLifecycle,NodeRestriction,OwnerReferencesPermissionEnforcement,PodNodeSelector,PersistentVolumeClaimResize,PodPreset,PodTolerationRestriction,ResourceQuota,ServiceAccount,StorageObjectInUseProtection,MutatingAdmissionWebhook,ValidatingAdmissionWebhook" \
         --kube-apiserver-arg="disable-admission-plugins=DenyEscalatingExec,ExtendedResourceToleration,ImagePolicyWebhook,LimitPodHardAntiAffinityTopology,NamespaceAutoProvision,Priority,EventRateLimit,PodSecurityPolicy" \
         --kube-controller-arg="horizontal-pod-autoscaler-use-rest-clients=true" \
         --pause-image=docker.io/juestnow/pause-amd64:3.1 \
         --resolv-conf="/etc/resolv.conf"'
----------------------------------------------------------------------------------------------------------------------------------
# 创建k3s 启动文件
vi /etc/systemd/system/k3s.service
-----------------------------------------------------------------------------------------------------------------------------
[Unit]
Description=Lightweight Kubernetes
Documentation=https://k3s.io
After=network-online.target

[Service]
Type=notify
EnvironmentFile=/etc/sysconfig/k3s.env
ExecStartPre=-/sbin/modprobe br_netfilter
ExecStartPre=-/sbin/modprobe overlay
ExecStart=/usr/local/bin/k3s \
    server $K3S_SERVER_OPTS \

KillMode=process
Delegate=yes
LimitNOFILE=1024000
LimitNPROC=1024000
LimitCORE=infinity
TasksMax=infinity
TimeoutStartSec=0
Restart=always
RestartSec=5s

[Install]
WantedBy=multi-user.target
# 启动k3s
systemctl enable k3s && systemctl start k3s
# 等待K3S 启动正常 然后关闭k3s
-----------------------------------------------
systemctl stop k3s
--------------------------------
# 复制K3S 生成的配置文件到其它master节点
scp -r /etc/rancher 192.168.30.51:/etc/rancher
scp -r /etc/rancher 192.168.30.52:/etc/rancher
scp -r /apps/k3s   192.168.30.51:/apps/
scp -r /apps/k3s    192.168.30.52:/apps/
-------------------------------------------
#启动 k3s-01 节点
-------------------------------------------
systemctl start k3s
-------------------------------------------
ssh 192.168.30.51,52 
systemctl enable k3s && systemctl start k3s
---------------------------------------------
# 验证k3s 节点是否启动正常
k3s  kubectl get node
# kubeconfig 文件生成账号密码 操作K3S 集群用到admin 权限
cat /etc/rancher/k3s/k3s.yaml
# 远程操作
scp /etc/rancher/k3s/k3s.yaml /root/.kube/config
vim /root/.kube/config
#127.0.0.1 改成远程服务器IP 192.168.30.50,51,52 测试所有节点是否能正常返回如果都返回正常证明集群部署成功

k3s agent 部署

# 依赖coredns 可以先部署coredns 也可以把--no-deploy=coredns  删除这边使用自建coredns
--------------------------------------------------------------------------------------------------------------------------
vi coredns.yaml
-------------------------------------------------------------------------------------------------------------------------
# __MACHINE_GENERATED_WARNING__

apiVersion: v1
kind: ServiceAccount
metadata:
  name: coredns
  namespace: kube-system
  labels:
      kubernetes.io/cluster-service: "true"
      addonmanager.kubernetes.io/mode: Reconcile
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
    addonmanager.kubernetes.io/mode: Reconcile
  name: system:coredns
rules:
- apiGroups:
  - ""
  resources:
  - endpoints
  - services
  - pods
  - namespaces
  verbs:
  - list
  - watch
- apiGroups:
  - ""
  resources:
  - nodes
  verbs:
  - get
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
    addonmanager.kubernetes.io/mode: EnsureExists
  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
  labels:
      addonmanager.kubernetes.io/mode: EnsureExists
data:
  Corefile: |
    .:53 {
        errors
        health
        kubernetes mddgame.local in-addr.arpa ip6.arpa {
            pods insecure
            upstream /etc/resolv.conf
            fallthrough in-addr.arpa ip6.arpa
        }
        prometheus :9153
        forward . /etc/resolv.conf
        cache 30
        reload
        loadbalance
    }
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: coredns
  namespace: kube-system
  labels:
    k8s-app: kube-dns
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
    kubernetes.io/name: "CoreDNS"
spec:
  # replicas: not specified here:
  # 1. In order to make Addon Manager do not reconcile this replicas parameter.
  # 2. Default is 1.
  # 3. 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
      annotations:
        seccomp.security.alpha.kubernetes.io/pod: 'docker/default'
    spec:
      priorityClassName: system-cluster-critical
      serviceAccountName: coredns
      tolerations:
        - key: "CriticalAddonsOnly"
          operator: "Exists"
      nodeSelector:
        beta.kubernetes.io/os: linux
      containers:
      - name: coredns
        image: coredns/coredns
        imagePullPolicy: Always
        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
        livenessProbe:
          httpGet:
            path: /health
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 60
          timeoutSeconds: 5
          successThreshold: 1
          failureThreshold: 5
        readinessProbe:
          httpGet:
            path: /health
            port: 8080
            scheme: HTTP
        securityContext:
          allowPrivilegeEscalation: false
          capabilities:
            add:
            - NET_BIND_SERVICE
            drop:
            - all
          readOnlyRootFilesystem: true
      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"
    addonmanager.kubernetes.io/mode: Reconcile
    kubernetes.io/name: "CoreDNS"
spec:
  selector:
    k8s-app: kube-dns
  clusterIP: 10.64.0.2
  ports:
  - name: dns
    port: 53
    protocol: UDP
  - name: dns-tcp
    port: 53
    protocol: TCP
  - name: metrics
    port: 9153
    protocol: TCP

# 创建coredns dns
k3s   kubectl apply -f coredns.yaml
k3s   kubectl  get pod -A
# 等待部署完成
# 安装依赖
--------------------------------------------
dnf install epel-release
---------------------------
dnf install   dnf-utils ipvsadm telnet wget net-tools conntrack ipset jq iptables curl sysstat libseccomp socat nfs-utils fuse fuse-devel
------------------------------------------------
# centos 8 不能自动加载ipvs 创建开机加载
cat << EOF > /etc/sysconfig/modules/ipvs.modules
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF
# /etc/sysconfig/modules/ipvs.modules 可执行权限
chmod +x /etc/sysconfig/modules/ipvs.modules
# 执行 /etc/sysconfig/modules/ipvs.modules
/etc/sysconfig/modules/ipvs.modules
-----------------------------------
# 获取token 任意master 节点 所有master 节点token 一点要一致
---------------------------------------------
cat /apps/k3s/server/node-token
K1000966fac151ec94a53040dadd727a4ef1ccac022aa8747f0b601ca33665417ea::node:0aa3ce3afaf275fd33ae6a2a9580d3a0
-----------------------------------------------------------------------------------------------------------------
# 创建k3s agent env
vi /etc/sysconfig/k3a.env
----------------------------------------------------------
K3S_AGENT_OPTS='--data-dir=/apps/k3s \
         --kube-proxy-arg="proxy-mode=ipvs" \
         --kube-proxy-arg="masquerade-all=true" \
         --pause-image=docker.io/juestnow/pause-amd64:3.1 \
         --resolv-conf="/etc/resolv.conf" \
         --server=https://192.168.30.59:6443 \
         --token=K1000966fac151ec94a53040dadd727a4ef1ccac022aa8747f0b601ca33665417ea::node:0aa3ce3afaf275fd33ae6a2a9580d3a0'
--------------------------------------------------------------------------------------------------------------------------------
# 创建 启动脚本
vi /etc/systemd/system/k3a.service
----------------------------------------------------------------------------------------------------
[Unit]
Description=Lightweight Kubernetes
Documentation=https://k3s.io
After=network-online.target

[Service]
Type=notify
EnvironmentFile=/etc/sysconfig/k3a.env
ExecStartPre=-/sbin/modprobe br_netfilter
ExecStartPre=-/sbin/modprobe overlay
ExecStart=/usr/local/bin/k3s \
     agent $K3S_AGENT_OPTS \

KillMode=process
Delegate=yes
LimitNOFILE=1024000
LimitNPROC=1024000
LimitCORE=infinity
TasksMax=infinity
TimeoutStartSec=0
Restart=always
RestartSec=5s

[Install]
WantedBy=multi-user.target
-----------------------------------------------------------------------------
# 启动 k3s agent
systemctl enable k3a && systemctl start k3a
# 验证 agent 是否加入集群
k3s kubectl get node
# 应该有work 名字的节点
# 这个与K8S 集群几乎没任何区别可以部署监控及kubernetes-dashboard及所有应用
# k3s 默认使用containerd kubelet 还是不能监控pod 网络当然切换成docker 就可以
# 单mater 部署这里就不展开讨论,网络上很多这样的示例。
# agent 会t同时连接3台master 节点任意节点关闭都不会对agent 节点有影响可以不用考虑 haproxy做代理

文章题目:k3s高可用部署
标题来源:http://njwzjz.com/article/pihipc.html