k8s1.20.5

1.前提知識 https://www.cnblogs.com/lizexiong/p/14882419.html

1.1 生產環境部署K8s集羣的兩種方式

  kubeadm

  Kubeadm是一個K8s部署工具,提供kubeadm init和kubeadm join,用於快速部署Kubernetes集羣。

  二進制包

  從github下載發行版的二進制包,手動部署每個組件,組成Kubernetes集羣。

  小結:Kubeadm降低部署門檻,但屏蔽了很多細節,遇到問題很難排查。如果想更容易可控,推薦使用二進制包部署Kubernetes集羣,雖然手動部署麻煩點,期間可以學習很多工作原理,也利於後期維護。

 

1.2 環境信息

  服務器要求:

  • 建議最小硬件配置:2核CPU、2G內存、30G硬盤
  • 服務器最好可以訪問外網,會有從網上拉取鏡像需求,如果服務器不能上網,需要提前下載對應鏡像並導入節點
軟件 版本
linux Centos 7.9.2009
Kubernetes 1.20.7
Docker 20.10.7
Etcd 3.4.9
Calico 3.19.1

 

角色 IP 組件 主機名

Master01

Load Balancer(Master)

172.21.161.110

172.21.161.120(vip)

kube-apiserver

kube-controller-manager

kube-scheduler

kubelet

kube-proxy

Nginx L4

master01

Master02

Load Balancer(Backup)

172.21.161.111

kube-apiserver

kube-controller-manager

kube-scheduler

kubelet

kube-proxy

Nginx L4

master02
etcd01 172.21.161.112 etcd  etcd01
etcd02 172.21.161.113 etcd  etcd02
etcd03 172.21.161.114 etcd  etcd03
Node01 172.21.161.115

kubelet

kube-proxy

docker

flannel

node01
Node02 172.21.161.116

kubelet

kube-proxy

docker

flannel

node02
public 172.21.161.149 跳板機 public

  這裏爲了使搭建過程更清晰,儘量將各角色分配到不同的機器上。每個機器都部署屬於自己的角色。比如生成證書就在public跳板機上去生成,然後推送到對應服務器。

 

1.3 拓撲信息

  單Master架構圖

  單Master服務器規劃:

角色 IP 組件 主機名
Master01 172.21.161.110

kube-apiserver

kube-controller-manager

kube-scheduler

master01
etcd01 172.21.161.112 etcd etcd01
etcd02 172.21.161.113 etcd etcd02
etcd03 172.21.161.114 etcd etcd03
Node01 172.21.161.115

kubelet

kube-proxy

docker

node01
Node02 172.21.161.116

kubelet

kube-proxy

docker

node02
public 172.21.161.149 跳板機 public

 

1.4 操作系統初始化設置

複製代碼
# 關閉防火牆 
systemctl stop firewalld 
systemctl disable firewalld 
 
# 關閉selinux 
sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久 
setenforce 0  # 臨時 
     
# 關閉swap 
swapoff -a  # 臨時 
sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久 
     
# 根據規劃設置主機名 
hostnamectl set-hostname <hostname> 
     
# 在需要的主機添加hosts,這裏一定要是追加,否則覆蓋了默認的記錄,在Calico和許多服務會出現問題
cat >> /etc/hosts << EOF 
172.21.161.110 master01
172.21.161.111 master02
172.21.161.115 node01
172.21.161.116 node02
172.21.161.112 etcd01    
172.21.161.113 etcd02
172.21.161.114 etcd03
172.21.161.149 public
EOF
     
# 將橋接的IPv4流量傳遞到iptables的鏈 
cat > /etc/sysctl.d/k8s.conf << EOF 
net.bridge.bridge-nf-call-ip6tables = 1 
net.bridge.bridge-nf-call-iptables = 1 
EOF
sysctl --system  # 生效 
     
# 時間同步 
yum install ntpdate chrony -y 
ntpdate time.windows.com
複製代碼

 

2.部署Etcd集羣

  Etcd是一個分佈式鍵值存儲系統,Kubernetes使用Etcd進行數據存儲,所以先準備一個Etcd數據庫,爲解決Etcd單點故障,應採用集羣方式部署,這裏使用3臺組建集羣,可容忍1臺機器故障,當然,你也可以使用5臺組建集羣,可容忍2臺機器故障。

 

2.1 準備cfssl證書生成工具

  cfssl是一個開源的證書管理工具,使用json文件生成證書,相比openssl更方便使用。

  找一臺服務器操作,這裏用public節點。證書的生成以及分配都在public上操作

複製代碼
#public節點操作
mkdir -p /k8s-deploy/cfssl/
cd /k8s-deploy/cfssl
wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo
複製代碼

  爲什麼需要證書?

  K8s所有組件採用https加密通信,這些組件一般由兩套根證書生成:K8S組件(apiserver)和Etcd。

  按照需求分類來說,這裏所有的服務組件controller-manager、scheduler、kubelet、kube-proxy、kubeclt等需要訪問apiserver,這裏需要一套。Apiserver訪問etcd集羣又是一套單獨的。所以這裏2套證書是2個不同自籤CA頒發的。

 

2.2 生成Etcd證書

  1.自簽證書頒發機構(CA)

  簽發證書都在public機器上。

  創建工作目錄:

#public節點操作
mkdir -p /k8s-deploy/cfssl/TLS/{etcd,k8s}
cd /k8s-deploy/cfssl/TLS/etcd

  自籤CA:

複製代碼
#public節點操作
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": "ShangHai",
            "ST": "ShangHai"
        }
    ]
}
EOF
複製代碼

  生成證書:

cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

  會生成ca.pem和ca-key.pem文件

  2.使用自籤CA簽發Etcd HTTPS證書

  創建證書申請文件:

複製代碼
#public節點操作
cat > server-csr.json << EOF
{
    "CN": "etcd",
    "hosts": [
    "172.21.161.112",
    "172.21.161.113",
    "172.21.161.114"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "ShangHai",
            "ST": "ShangHai"
        }
    ]
}
EOF
複製代碼

  注意:上述文件hosts字段中IP爲所有etcd節點的集羣內部通信IP,一個都不能少!爲了方便後期擴容可以多寫幾個預留的IP。

  生成證書:

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server

  會生成server.pem和server-key.pem文件。

 

2.3 從Github下載二進制文件

  下載地址:https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz

 

2.4 部署Etcd集羣

  以下在etcd節點1上操作,爲簡化操作,待會將節點1生成的所有文件拷貝到節點2和節點3.

  1.創建工作目錄並解壓二進制包

#etcd01節點操作
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.創建etcd配置文件

複製代碼
#etcd01節點操作
cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://172.21.161.112:2380"
ETCD_LISTEN_CLIENT_URLS="https://172.21.161.112:2379"
 
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.21.161.112:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://172.21.161.112:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://172.21.161.112:2380,etcd-2=https://172.21.161.113:2380,etcd-3=https://172.21.161.114:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF
複製代碼
  • ETCD_NAME:節點名稱,集羣中唯一
  • ETCD_DATA_DIR:數據目錄
  • ETCD_LISTEN_PEER_URLS:集羣通信監聽地址
  • ETCD_LISTEN_CLIENT_URLS:客戶端訪問監聽地址
  • ETCD_INITIAL_ADVERTISE_PEERURLS:集羣通告地址
  • ETCD_ADVERTISE_CLIENT_URLS:客戶端通告地址
  • ETCD_INITIAL_CLUSTER:集羣節點地址
  • ETCD_INITIALCLUSTER_TOKEN:集羣Token
  • ETCD_INITIALCLUSTER_STATE:加入集羣的當前狀態,new是新集羣,existing表示加入已有集羣

  3.systemd管理etcd

複製代碼
#etcd01節點操作
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
複製代碼

  4.拷貝剛纔生成的證書

  在public上把剛纔生成的證書拷貝到etcd01配置文件中的路徑:(只有這裏是在public上操作,其餘都是在etc01上操作)

[[email protected] etcd]# scp -r /k8s-deploy/cfssl/TLS/etcd/ca*pem /k8s-deploy/cfssl/TLS/etcd/server*pem [email protected]:/opt/etcd/ssl

  5.啓動並設置開機啓動

#etcd01節點操作
systemctl daemon-reload
#啓動的時候會hold住,因爲其它兩個節點沒有配置,一直在尋找其它節點
systemctl start etcd
systemctl enable etcd

  6.將上面節點1所有生成的文件拷貝到節點2和節點3

#etcd01節點操作
scp -r /opt/etcd/ [email protected]:/opt/
scp /usr/lib/systemd/system/etcd.service [email protected]:/usr/lib/systemd/system/
scp -r /opt/etcd/ [email protected]:/opt/
scp /usr/lib/systemd/system/etcd.service [email protected]:/usr/lib/systemd/system/

  然後在節點2和節點3分別修改etcd.conf配置文件中的節點名稱和當前服務器IP:(總共5處)

複製代碼
vi /opt/etcd/cfg/etcd.conf
#[Member]
ETCD_NAME="etcd-1"   # 修改此處,節點2改爲etcd-2,節點3改爲etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://172.21.161.112:2380"   # 修改此處爲當前服務器IP
ETCD_LISTEN_CLIENT_URLS="https:// 172.21.161.112:2379" # 修改此處爲當前服務器IP

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https:// 172.21.161.112:2380" # 修改此處爲當前服務器IP
ETCD_ADVERTISE_CLIENT_URLS="https:// 172.21.161.112:2379" # 修改此處爲當前服務器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://172.21.161.112:2380,etcd-2=https://172.21.161.113:2380,etcd-3=https://172.21.161.114:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
複製代碼

  最後啓動etcd並設置開機啓動,同上。

  7.查看集羣狀態

複製代碼
[[email protected] bin]# ETCDCTL_API=3 /opt/etcd/bin/etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://172.21.161.112:2379,https://172.21.161.113:2379,https://172.21.161.114:2379" endpoint health --write-out=table
+-----------------------------+--------+-------------+-------+
|          ENDPOINT           | HEALTH |    TOOK     | ERROR |
+-----------------------------+--------+-------------+-------+
| https://172.21.161.112:2379 |   true | 50.191672ms |       |
| https://172.21.161.113:2379 |   true | 52.394036ms |       |
| https://172.21.161.114:2379 |   true | 46.009422ms |       |
+-----------------------------+--------+-------------+-------+
複製代碼

  如果有問題查看日誌:/var/log/message或者journalctl -f -u etcd

 

3.安裝Docker

  這裏使用Docker作爲容器引擎,也可以換成別的,例如containerd

  下載地址:https://download.docker.com/linux/static/stable/x86_64/docker-20.10.7.tgz

  以下在所有節點操作。這裏採用二進制安裝,用yum安裝也一樣。本節其實已經用yum安裝一遍了,這裏只是做一個源碼的演示。

 

3.1 解壓二進制包

tar zxvf docker-20.10.7.tgz
mv docker/* /usr/bin

 

3.2 systemd管理docker

複製代碼
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
複製代碼

 

3.3 創建配置文件

mkdir /etc/docker
cat > /etc/docker/daemon.json << EOF
{
  "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF
  • registry-mirrors 阿里雲鏡像加速器

 

3.4 啓動並設置開機啓動

systemctl daemon-reload
systemctl start docker
systemctl enable docker

 

4.部署Master

4.1 生成kube-apiserver證書

  1.自簽證書頒發機構(CA)

  證書操作在public機器上,這是另一套獨立etcd的自籤ca證書

複製代碼
# 切換工作目錄(public)
cd /k8s-deploy/cfssl/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": "ShangHai",
            "ST": "ShangHai",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF
複製代碼

  生成證書:

cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

  會生成ca.pem和ca-key.pem文件。

  2.使用自籤CA簽發kube-apiserver HTTPS證書

  創建證書申請文件:

複製代碼
#public節點操作
cat > server-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "172.21.161.110",
      "172.21.161.111",
      "172.21.161.120",
      "kubernetes",
      "kubernetes.default",
      "kubernetes.default.svc",
      "kubernetes.default.svc.cluster",
      "kubernetes.default.svc.cluster.local"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "ShangHai",
            "ST": "ShangHai",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF
複製代碼

  注:上述文件hosts字段中IP爲所有Master/LB/VIP IP,一個都不能少!爲了方便後期擴容可以多寫幾個預留的IP。

  生成證書:

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare server

  會生成server.pem和server-key.pem文件。

 

4.2 從Github下載二進制文件

  下載地址: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.20.md

  注:打開鏈接你會發現裏面有很多包,下載一個server包就夠了,包含了Master和Worker Node二進制文件。

 

4.3 解壓二進制包

#master01節點操作
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/

 

4.4 部署kube-apiserver

  1.創建配置文件

複製代碼
#master01節點操作
cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--etcd-servers=https://172.21.161.112:2379,https://172.21.161.113:2379,https://172.21.161.114:2379 \\
--bind-address=172.21.161.110 \\
--secure-port=6443 \\
--advertise-address=172.21.161.110 \\
--allow-privileged=true \\
--service-cluster-ip-range=10.0.0.0/24 \\
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \\
--authorization-mode=RBAC,Node \\
--enable-bootstrap-token-auth=true \\
--token-auth-file=/opt/kubernetes/cfg/token.csv \\
--service-node-port-range=30000-32767 \\
--kubelet-client-certificate=/opt/kubernetes/ssl/server.pem \\
--kubelet-client-key=/opt/kubernetes/ssl/server-key.pem \\
--tls-cert-file=/opt/kubernetes/ssl/server.pem  \\
--tls-private-key-file=/opt/kubernetes/ssl/server-key.pem \\
--client-ca-file=/opt/kubernetes/ssl/ca.pem \\
--service-account-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--service-account-issuer=api \\
--service-account-signing-key-file=/opt/kubernetes/ssl/server-key.pem \\
--etcd-cafile=/opt/etcd/ssl/ca.pem \\
--etcd-certfile=/opt/etcd/ssl/server.pem \\
--etcd-keyfile=/opt/etcd/ssl/server-key.pem \\
--requestheader-client-ca-file=/opt/kubernetes/ssl/ca.pem \\
--proxy-client-cert-file=/opt/kubernetes/ssl/server.pem \\
--proxy-client-key-file=/opt/kubernetes/ssl/server-key.pem \\
--requestheader-allowed-names=kubernetes \\
--requestheader-extra-headers-prefix=X-Remote-Extra- \\
--requestheader-group-headers=X-Remote-Group \\
--requestheader-username-headers=X-Remote-User \\
--enable-aggregator-routing=true \\
--audit-log-maxage=30 \\
--audit-log-maxbackup=3 \\
--audit-log-maxsize=100 \\
--audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
EOF

複製代碼

  注:上面兩個\\第一個是轉義符,第二個是換行符,使用轉義符是爲了使用EOF保留換行符。

  • --logtostderr:啓用日誌
  • ---v:日誌等級
  • --log-dir:日誌目錄
  • --etcd-servers:etcd集羣地址
  • --bind-address:監聽地址
  • --secure-port:https安全端口
  • --advertise-address:集羣通告地址
  • --allow-privileged:啓用授權
  • --service-cluster-ip-range:Service虛擬IP地址段
  • --enable-admission-plugins:准入控制模塊
  • --authorization-mode:認證授權,啓用RBAC授權和節點自管理
  • --enable-bootstrap-token-auth:啓用TLS bootstrap機制
  • --token-auth-file:bootstrap token文件
  • --service-node-port-range:Service nodeport類型默認分配端口範圍
  • --kubelet-client-xxx:apiserver訪問kubelet客戶端證書
  • --tls-xxx-file:apiserver https證書
  • 1.20版本必須加的參數:--service-account-issuer,--service-account-signing-key-file
  • --etcd-xxxfile:連接Etcd集羣證書
  • --audit-log-xxx:審計日誌
  • 啓動聚合層相關配置:--requestheader-client-ca-file,--proxy-client-cert-file,--proxy-client-key-file,--requestheader-allowed-names,--requestheader-extra-headers-prefix,--requestheader-group-headers,--requestheader-username-headers,--enable-aggregator-routing

  2.拷貝剛纔生成的證書(public)

  把剛纔生成的證書拷貝到配置文件中的路徑:

[[email protected] k8s]#scp -r /k8s-deploy/cfssl/TLS/k8s/ca*pem /k8s-deploy/cfssl/TLS/k8s/server*pem [email protected]:/opt/kubernetes/ssl

  注意,因爲etcd和master不在一臺機器部署,這裏etcd的證書也要拷貝

#首先master01要創建目錄mkdir /opt/etcd/ssl -p
[[email protected] bin]# mkdir /opt/etcd/ssl -p
[[email protected] k8s]# scp -r /k8s-deploy/cfssl/TLS/etcd/ca*pem /k8s-deploy/cfssl/TLS/etcd/server*pem [email protected]:/opt/etcd/ssl

  3.啓用 TLS Bootstrapping 機制

  TLS Bootstraping:Master apiserver啓用TLS認證後,Node節點kubelet和kube-proxy要與kube-apiserver進行通信,必須使用CA簽發的有效證書纔可以,當Node節點很多時,這種客戶端證書頒發需要大量工作,同樣也會增加集羣擴展複雜度。爲了簡化流程,Kubernetes引入了TLS bootstraping機制來自動頒發客戶端證書,kubelet會以一個低權限用戶自動向apiserver申請證書,kubelet的證書由apiserver動態簽署。所以強烈建議在Node上使用這種方式,目前主要用於kubelet,kube-proxy還是由我們統一頒發一個證書。

  TLS bootstraping 工作流程:

  創建上述配置文件中token文件:

#master01節點操作
cat > /opt/kubernetes/cfg/token.csv << EOF
c47ffb939f5ca36231d9e3121a252940,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF

  格式:token,用戶名,UID,用戶組

  token也可自行生成替換:

head -c 16 /dev/urandom | od -An -t x | tr -d ' '

  4.systemd管理apiserver

複製代碼
#master01節點操作
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
複製代碼

  5.啓動並設置開機啓動

#master01節點操作
systemctl daemon-reload
systemctl start kube-apiserver 
systemctl enable kube-apiserver

  啓動會有異常,這裏不影響運行及後續操作,可以忽略,具體解決辦法參考以下鏈接

  https://github.com/kubernetes/kubernetes/issues/76956

 

4.5 部署kube-controller-manager

  1.創建配置文件

複製代碼
#master01節點操作
cat > /opt/kubernetes/cfg/kube-controller-manager.conf << EOF
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--leader-elect=true \\
--kubeconfig=/opt/kubernetes/cfg/kube-controller-manager.kubeconfig \\
--bind-address=127.0.0.1 \\
--allocate-node-cidrs=true \\
--cluster-cidr=10.244.0.0/16 \\
--service-cluster-ip-range=10.0.0.0/24 \\
--cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem \\
--cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem  \\
--root-ca-file=/opt/kubernetes/ssl/ca.pem \\
--service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--cluster-signing-duration=87600h0m0s"
EOF
複製代碼
  • --kubeconfig:連接apiserver配置文件
  • --leader-elect:當該組件啓動多個時,自動選舉(HA)
  • --cluster-signing-cert-file/--cluster-signing-key-file:自動爲kubelet頒發證書的CA,與apiserver保持一致

  2.生成kubeconfig證書以及配置文件

  生成kube-controller-manager證書:(public)

複製代碼
# 切換工作目錄(public,證書一般要切換回public機器操作)
cd /k8s-deploy/cfssl/TLS/k8s/

# 創建證書請求文件
cat > kube-controller-manager-csr.json << EOF
{
  "CN": "system:kube-controller-manager",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "ShangHai", 
      "ST": "ShangHai",
      "O": "system:masters",
      "OU": "System"
    }
  ]
}
EOF

# 生成證書
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager
複製代碼

  生成kubeconfig文件(以下是shell命令,直接在終端執行):

  這裏生成的證書文件因爲在public,所以要拷貝到master01的相應目錄

[[email protected] k8s]# scp -r /k8s-deploy/cfssl/TLS/k8s/kube-controller-manager*pem [email protected]:/opt/kubernetes/ssl
複製代碼
#master01節點操作
KUBE_CONFIG="/opt/kubernetes/cfg/kube-controller-manager.kubeconfig"
KUBE_APISERVER="https://172.21.161.110:6443"

kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials kube-controller-manager \
  --client-certificate=/opt/kubernetes/ssl/kube-controller-manager.pem \
  --client-key=/opt/kubernetes/ssl/kube-controller-manager-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-controller-manager \
  --kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
#這裏配置文件就不展示了
複製代碼

  3.systemd管理controller-manager

複製代碼
#master01節點操作
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
複製代碼

  4.啓動並設置開機啓動

#master01節點操作
systemctl daemon-reload
systemctl start kube-controller-manager
systemctl enable kube-controller-manager

  5.可能出現的問題

  對後續不影響,時間充裕的可以嘗試排錯。

 

4.6 部署kube-scheduler  

  1.創建配置文件

複製代碼
#master01節點操作
cat > /opt/kubernetes/cfg/kube-scheduler.conf << EOF
KUBE_SCHEDULER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--leader-elect \\
--kubeconfig=/opt/kubernetes/cfg/kube-scheduler.kubeconfig \\
--bind-address=127.0.0.1"
EOF
複製代碼
  • --kubeconfig:連接apiserver配置文件
  • --leader-elect:當該組件啓動多個時,自動選舉(HA)

  2.生成kubeconfig證書以及配置文件

  生成kube-scheduler證書:

複製代碼
# 切換工作目錄(public,證書一般要切換回public機器操作)
cd /k8s-deploy/cfssl/TLS/k8s/

# 創建證書請求文件
cat > kube-scheduler-csr.json << EOF
{
  "CN": "system:kube-scheduler",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "ShangHai",
      "ST": "ShangHai",
      "O": "system:masters",
      "OU": "System"
    }
  ]
}
EOF

# 生成證書
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-scheduler-csr.json | cfssljson -bare kube-scheduler
複製代碼

  生成kubeconfig文件(以下是shell命令,直接在終端執行):

  這裏生成的證書文件因爲在public,所以要拷貝到master01的相應目錄

[[email protected] k8s]# scp -r /k8s-deploy/cfssl/TLS/k8s/kube-scheduler*pem [email protected]:/opt/kubernetes/ssl
複製代碼
#master01節點操作
KUBE_CONFIG="/opt/kubernetes/cfg/kube-scheduler.kubeconfig"
KUBE_APISERVER="https://172.21.161.110:6443"

kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials kube-scheduler \
  --client-certificate=/opt/kubernetes/ssl/kube-scheduler.pem \
  --client-key=/opt/kubernetes/ssl/kube-scheduler-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-scheduler \
  --kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
複製代碼

  3.systemd管理scheduler

複製代碼
#master01節點操作
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
複製代碼

  4.啓動並設置開機啓動

#master01節點操作
systemctl daemon-reload
systemctl start kube-scheduler
systemctl enable kube-scheduler

  出現以下問題的,重頭開始做吧

 

4.7 查看集羣狀態(public)

  生成kubectl連接集羣的證書:

複製代碼
#想訪問k8s集羣的機器操作,這裏使用public
cat > admin-csr.json <<EOF
{
  "CN": "admin",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "ShangHai",
      "ST": "ShangHai",
      "O": "system:masters",
      "OU": "System"
    }
  ]
}
EOF

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin
複製代碼

  生成kubeconfig文件:

複製代碼
mkdir /root/.kube

KUBE_CONFIG="/root/.kube/config"
KUBE_APISERVER="https://172.21.161.110:6443"

kubectl config set-cluster kubernetes \
  --certificate-authority=/k8s-deploy/cfssl/TLS/k8s/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials cluster-admin \
  --client-certificate=/k8s-deploy/cfssl/TLS/k8s/admin.pem \
  --client-key=/k8s-deploy/cfssl/TLS/k8s/admin-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
  --cluster=kubernetes \
  --user=cluster-admin \
  --kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
複製代碼

  通過kubectl工具查看當前集羣組件狀態:

複製代碼
kubectl get cs
NAME                STATUS    MESSAGE             ERROR
scheduler             Healthy   ok                  
controller-manager    Healthy   ok                  
etcd-2               Healthy   {"health":"true"}   
etcd-1               Healthy   {"health":"true"}   
etcd-0               Healthy   {"health":"true"}  
複製代碼

  如上輸出說明Master節點組件運行正常。

  也可以順便同時讓master可以訪問,在public將config文件拷貝至master01節點即可

[[email protected] ssl]# mkdir /root/.kube
[[email protected] ~]# scp -r /root/.kube/ [email protected]:/root

 

4.8 授權kubelet-bootstrap用戶允許請求證書

#創建node必備,不然node的kubelet無法啓動,就是創建一個可以申請證書的用戶
kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap

 

5.部署Worker Node

5.1 創建工作目錄並拷貝二進制文件

  在所有worker node創建工作目錄:

mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 

  從master至node節點:

cd /tools/kubernetes/server/bin/
scp -r kubelet kube-proxy [email protected]:/opt/kubernetes/bin/
scp /opt/kubernetes/ssl/ca.pem [email protected]:/opt/kubernetes/ssl/
scp /usr/bin/kubectl node01:/usr/bin

 

5.2 部署kubelet

  1.創建配置文件

複製代碼
#node01節點操作
cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=node01 \\
--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=lizexiong/pause-amd64:3.0"
EOF
複製代碼
  • --hostname-override:顯示名稱,集羣中唯一
  • --network-plugin:啓用CNI
  • --kubeconfig:空路徑,會自動生成,後面用於連接apiserver
  • --bootstrap-kubeconfig:首次啓動向apiserver申請證書
  • --config:配置參數文件
  • --cert-dir:kubelet證書生成目錄
  • --pod-infra-container-image:管理Pod網絡容器的鏡像

  如果主機名在通過master審批之後更改了,或者是什麼原因更改了,node就會出現下面的錯誤提示

  2.配置參數文件

複製代碼
#node01節點操作
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
複製代碼

  3.生成kubelet初次加入集羣引導kubeconfig文件

複製代碼
#node01節點操作
KUBE_CONFIG="/opt/kubernetes/cfg/bootstrap.kubeconfig"
KUBE_APISERVER="https://172.21.161.110:6443" # apiserver IP:PORT
TOKEN="c47ffb939f5ca36231d9e3121a252940" # 與token.csv裏保持一致

# 生成 kubelet bootstrap kubeconfig 配置文件
kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials "kubelet-bootstrap" \
  --token=${TOKEN} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
  --cluster=kubernetes \
  --user="kubelet-bootstrap" \
  --kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
複製代碼

  4.systemd管理kubelet

複製代碼
#node01節點操作
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
複製代碼

  5.啓動並設置開機啓動

#node01節點操作
systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet

 

5.3 批准kubelet證書申請並加入集羣

複製代碼
# 查看kubelet證書請求
[[email protected] k8s]# kubectl get csr
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-84G21oPC3hDbyMwZN62ExQDI4D2Xa8IO74zHtlWRhD8   60s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 批准申請
[[email protected] k8s]# kubectl certificate approve node-csr-84G21oPC3hDbyMwZN62ExQDI4D2Xa8IO74zHtlWRhD8
certificatesigningrequest.certificates.k8s.io/node-csr-84G21oPC3hDbyMwZN62ExQDI4D2Xa8IO74zHtlWRhD8 approved
[[email protected] k8s]# kubectl get node
NAME         STATUS     ROLES    AGE   VERSION
node01   NotReady   <none>   3s    v1.20.7
#這個時候節點狀態肯定是NotReady,安裝Calico之後就會好
複製代碼

  注意:可能出現的報錯

複製代碼
[[email protected] k8s]# kubectl certificate approve node-csr-84G21oPC3hDbyMwZN62ExQDI4D2Xa8IO74zHtlWRhD8
No resources found
error: no kind "CertificateSigningRequest" is registered for version "certificates.k8s.io/v1" in scheme "k8s.io/kubernetes/pkg/kubectl/scheme/scheme.go:28"
#因爲客戶端版本不對
[[email protected] k8s]# kubectl version --short
Client Version: v1.12.7
Server Version: v1.20.7
複製代碼

  注:由於網絡插件還沒有部署,節點會沒有準備就緒 NotReady

 

5.4 部署kube-proxy

  1.創建配置文件

複製代碼
#node01節點操作
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
複製代碼

  2.配置參數文件

複製代碼
#node01節點操作
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: node01
clusterCIDR: 10.0.0.0/24
EOF
複製代碼

  3.生成kube-proxy.kubeconfig文件

複製代碼
# 切換工作目錄(public)
cd /k8s-deploy/cfssl/TLS/k8s/


# 創建證書請求文件
cat > kube-proxy-csr.json << EOF
{
  "CN": "system:kube-proxy",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "ShangHai",
      "ST": "ShangHai",
      "O": "k8s",
      "OU": "System"
    }
  ]
}
EOF

# 生成證書
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy
#將證書從public拷貝至node
[[email protected] k8s]# scp /k8s-deploy/cfssl/TLS/k8s/kube-proxy*pem [email protected]:/opt/kubernetes/ssl
複製代碼
複製代碼
#node01節點操作
#生成kubeconfig文件:
KUBE_CONFIG="/opt/kubernetes/cfg/kube-proxy.kubeconfig"
KUBE_APISERVER="https://172.21.161.110:6443"

kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials kube-proxy \
  --client-certificate=/opt/kubernetes/ssl/kube-proxy.pem \
  --client-key=/opt/kubernetes/ssl/kube-proxy-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-proxy \
  --kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
複製代碼

  4.systemd管理kube-proxy

複製代碼
#node01節點操作
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
複製代碼

  5.啓動並設置開機啓動

#node01節點操作
systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy

  啓動後會有報錯,只有在calico插件安裝完成後纔會正常。

 

5.5 部署網絡組件

  Calico是一個純三層的數據中心網絡方案,是目前Kubernetes主流的網絡方案。

  下載地址: https://docs.projectcalico.org/getting-started/kubernetes/self-managed-onprem/onpremises

  部署Calico:

#哪裏有yaml文件可以訪問集羣,就在哪裏操作
curl https://docs.projectcalico.org/manifests/calico.yaml -O
kubectl apply -f calico.yaml
kubectl get pods -n kube-system

  等Calico Pod都Running,節點也會準備就緒:(鏡像在國外,可能會有些慢)

kubectl get node
NAME         STATUS   ROLES    AGE   VERSION
node01      Ready    <none>   37m   v1.20.7

  注意:這裏有個問題需要注意

  準備環境的時候,各node節點的/etc/hosts裏面的默認記錄,也就是localhost記錄,一定不要刪除或者誤刪,否則會出現以下報錯,pod是運行的,但是健康檢查一直無法通過。

 

5.6 授權apiserver訪問kubelet

  應用場景:例如kubectl logs

複製代碼
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
複製代碼

 

5.7 新增加Worker Node

  1.拷貝已部署好的Node相關文件到新節點

[[email protected] cfg]# scp -r /opt/kubernetes/ [email protected]:/opt           #包括,程序,證書,都在裏面,主要需要ca.pem
[[email protected] cfg]# scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service [email protected]:/usr/lib/systemd/system

  2.刪除kubelet證書和kubeconfig文件

#node02節點操作
rm -f /opt/kubernetes/cfg/kubelet.kubeconfig    #審批通過後會自動生成
rm -f /opt/kubernetes/ssl/kubelet-client*

  注:這幾個文件是證書申請審批後自動生成的,每個Node不同,必須刪除

  3.修改主機名

#node02節點操作
vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=node01 #修改成真實主機名

vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: node01 #修改成真實主機名

  4.啓動並設置開機啓動

#node02節點操作
systemctl daemon-reload
systemctl start kubelet kube-proxy
systemctl enable kubelet kube-proxy

  5.在Master上批准新Node kubelet證書申請

複製代碼
# 查看證書請求
kubectl get csr
NAME           AGE   SIGNERNAME                    REQUESTOR           CONDITION
node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro   89s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 授權請求
kubectl certificate approve node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro
複製代碼

  6.查看Node狀態

kubectl get node
NAME       STATUS   ROLES    AGE     VERSION
node01    Ready    <none>   47m     v1.20.7
node02    Ready    <none>   6m49s   v1.20.7

 

6.部署Dashboard和CoreDNS

6.1 部署Dashboard

#哪裏有yaml文件可以訪問集羣,就在哪裏操作
kubectl apply -f kubernetes-dashboard.yaml
# 查看部署
kubectl get pods,svc -n kubernetes-dashboard

  訪問地址:https://NodeIP:30001

  創建service account並綁定默認cluster-admin管理員集羣角色:

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}')

  使用輸出的token登錄Dashboard。

 

6.2 部署CoreDNS

  CoreDNS用於集羣內部Service名稱解析。

#哪裏有yaml文件可以訪問集羣,就在哪裏操作
kubectl apply -f coredns.yaml 

kubectl get pods -n kube-system  
NAME                          READY   STATUS    RESTARTS   AGE 
coredns-5ffbfd976d-j6shb      1/1     Running   0          32s

  DNS解析測試:

複製代碼
#創建之前要開啓api訪問kubelet權限,不然無法進入容器
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
複製代碼

  解析沒問題。

  至此一個單Master集羣就搭建完成了!這個環境就足以滿足學習實驗了,下面繼續擴容多Master集羣!

 

7.擴容多Master(高可用架構)

  Kubernetes作爲容器集羣系統,通過健康檢查+重啓策略實現了Pod故障自我修復能力,通過調度算法實現將Pod分佈式部署,並保持預期副本數,根據Node失效狀態自動在其他Node拉起Pod,實現了應用層的高可用性。

  針對Kubernetes集羣,高可用性還應包含以下兩個層面的考慮:Etcd數據庫的高可用性和Kubernetes Master組件的高可用性。 而Etcd我們已經採用3個節點組建集羣實現高可用,本節將對Master節點高可用進行說明和實施。

  Master節點扮演着總控中心的角色,通過不斷與工作節點上的Kubelet和kube-proxy進行通信來維護整個集羣的健康工作狀態。如果Master節點故障,將無法使用kubectl工具或者API做任何集羣管理。

  Master節點主要有三個服務kube-apiserver、kube-controller-manager和kube-scheduler,其中kube-controller-manager和kube-scheduler組件自身通過選擇機制已經實現了高可用,所以Master高可用主要針對kube-apiserver組件,而該組件是以HTTP API提供服務,因此對他高可用與Web服務器類似,增加負載均衡器對其負載均衡即可,並且可水平擴容。

  多Master架構圖:

 

7.1 部署Master2

  現在需要再增加一臺新服務器,作爲Master2 Node,IP是172.21.161.111。

  爲了節省資源你也可以將之前部署好的Worker Node1複用爲Master2 Node角色(即部署Master組件,這裏不這麼做)

  Master02 與已部署的Master01所有操作一致。所以我們只需將Master01所有K8s文件拷貝過來,再修改下服務器IP和主機名啓動即可

  1.準備工作

  安裝docker及更改主機名以及主機名加入到所有機器的映射

  2.創建etcd證書目錄

  在Master02創建etcd證書目錄:

#master02節點操作
mkdir -p /opt/etcd/ssl

  3.拷貝文件(Master01操作)

  拷貝Master1上所有K8s文件和etcd證書到Master2:

scp -r /opt/kubernetes [email protected]:/opt
scp -r /opt/etcd/ssl [email protected]:/opt/etcd
scp /usr/lib/systemd/system/kube* [email protected]:/usr/lib/systemd/system
scp /usr/bin/kubectl  [email protected]:/usr/bin
scp -r /root/.kube [email protected]:/root

  4.刪除證書文件

  刪除kubelet證書和kubeconfig文件:

#master02節點操作
#如果master沒有部署node節點組件,可忽略這一步
rm -f /opt/kubernetes/cfg/kubelet.kubeconfig 
rm -f /opt/kubernetes/ssl/kubelet*

  5.修改配置文件IP和主機名

  修改apiserver、kubelet和kube-proxy配置文件爲本地IP: (7處修改)

複製代碼
#master02節點操作
vi /opt/kubernetes/cfg/kube-apiserver.conf 
...
--bind-address=172.21.161.111 \
--advertise-address=172.21.161.111 \
...
 
vi /opt/kubernetes/cfg/kube-controller-manager.kubeconfig
server: https:// 172.21.161.111:6443
 
vi /opt/kubernetes/cfg/kube-scheduler.kubeconfig
server: https:// 172.21.161.111:6443



vi root/.kube/config
server: https://172.21.161.111:6443
 
#下面的2處無視,因爲目前master節點還沒部署node組件
vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=master02
 
vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: master02
複製代碼

  6.啓動設置開機啓動

#master02節點操作
systemctl daemon-reload
systemctl start kube-apiserver kube-controller-manager kube-scheduler 
systemctl enable kube-apiserver kube-controller-manager kube-scheduler 

  7.查看集羣狀態

複製代碼
#master02節點操作
kubectl get cs
NAME                STATUS    MESSAGE             ERROR
scheduler             Healthy   ok                  
controller-manager       Healthy   ok                  
etcd-1               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"}   
etcd-0               Healthy   {"health":"true"}
複製代碼

 

7.2 部署Nginx+Keepalived高可用負載均衡器

  kube-apiserver高可用架構圖:

  • Nginx是一個主流Web服務和反向代理服務器,這裏用四層實現對apiserver實現負載均衡。
  • Keepalived是一個主流高可用軟件,基於VIP綁定實現服務器雙機熱備,在上述拓撲中,Keepalived主要根據Nginx運行狀態判斷是否需要故障轉移(漂移VIP),例如當Nginx主節點掛掉,VIP會自動綁定在Nginx備節點,從而保證VIP一直可用,實現Nginx高可用。

  注1:爲了節省機器,這裏與K8s Master節點機器複用。也可以獨立於k8s集羣之外部署,只要nginx與apiserver能通信就行。

  注2:如果你是在公有云上,一般都不支持keepalived,那麼你可以直接用它們的負載均衡器產品,直接負載均衡多臺Master kube-apiserver,架構與上面一樣。

  在兩臺Master節點操作。

  1.安裝軟件包(主/備)

yum install epel-release -y
yum install nginx keepalived -y

  2.Nginx配置文件(主/備一樣)

複製代碼
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;
}
 
# 四層負載均衡,爲兩臺Master apiserver組件提供負載均衡
stream {
 
    log_format  main  '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent';
 
    access_log  /var/log/nginx/k8s-access.log  main;
 
    upstream k8s-apiserver {
       server 172.21.161.110:6443;   # Master1 APISERVER IP:PORT
       server 172.21.161.111:6443;   # Master2 APISERVER IP:PORT
    }
    
    server {
       listen 16443; # 由於nginx與master節點複用,這個監聽端口不能是6443,否則會衝突
       proxy_pass k8s-apiserver;
    }
}
 
http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';
 
    access_log  /var/log/nginx/access.log  main;
 
    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   65;
    types_hash_max_size 2048;
 
    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;
 
    server {
        listen       80 default_server;
        server_name  _;
 
        location / {
        }
    }
}
EOF
複製代碼

  3.keepalived配置文件(Nginx Master)

複製代碼
cat > /etc/keepalived/keepalived.conf << EOF
global_defs { 
   notification_email { 
     [email protected] 
     [email protected] 
     [email protected] 
   } 
   notification_email_from [email protected]  
   smtp_server 127.0.0.1 
   smtp_connect_timeout 30 
   router_id NGINX_MASTER
} 
 
vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"
}
 
vrrp_instance VI_1 { 
    state MASTER 
    interface ens192  # 修改爲實際網卡名
    virtual_router_id 51 # VRRP 路由 ID實例,每個實例是唯一的 
    priority 100    # 優先級,備服務器設置 90 
    advert_int 1    # 指定VRRP 心跳包通告間隔時間,默認1秒 
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    # 虛擬IP
    virtual_ipaddress { 
        172.21.161.120/24
    } 
    track_script {
        check_nginx
    } 
}
EOF
複製代碼
  • vrrp_script:指定檢查nginx工作狀態腳本(根據nginx狀態判斷是否故障轉移)
  • virtual_ipaddress:虛擬IP(VIP)

  準備上述配置文件中檢查nginx運行狀態的腳本:

複製代碼
cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ss -antp |grep 16443 |egrep -cv "grep|$$")

if [ "$count" -eq 0 ];then
    exit 1
else
    exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh
複製代碼

  注:keepalived根據腳本返回狀態碼(0爲工作正常,非0不正常)判斷是否故障轉移。

  4.keepalived配置文件(Nginx Backup)

複製代碼
cat > /etc/keepalived/keepalived.conf << EOF
global_defs { 
   notification_email { 
     [email protected] 
     [email protected] 
     [email protected] 
   } 
   notification_email_from [email protected]  
   smtp_server 127.0.0.1 
   smtp_connect_timeout 30 
   router_id NGINX_BACKUP
} 
 
vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"
}
 
vrrp_instance VI_1 { 
    state BACKUP 
    interface ens192
    virtual_router_id 51 # VRRP 路由 ID實例,每個實例是唯一的 
    priority 90
    advert_int 1
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    virtual_ipaddress { 
        172.21.161.120/24
    } 
    track_script {
        check_nginx
    } 
}
EOF
複製代碼

  準備上述配置文件中檢查nginx運行狀態的腳本

複製代碼
cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ss -antp |grep 16443 |egrep -cv "grep|$$")

if [ "$count" -eq 0 ];then
    exit 1
else
    exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh
複製代碼

  注:keepalived根據腳本返回狀態碼(0爲工作正常,非0不正常)判斷是否故障轉移。

  5.啓動並設置開機啓動

systemctl daemon-reload
systemctl start nginx keepalived
systemctl enable nginx keepalived

  6.查看keepalived工作狀態

複製代碼
[[email protected] .kube]# ip addr
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: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:50:56:ba:aa:a6 brd ff:ff:ff:ff:ff:ff
    inet 172.21.161.110/24 brd 172.21.161.255 scope global noprefixroute ens192
       valid_lft forever preferred_lft forever
    inet 172.21.161.120/24 scope global secondary ens192
       valid_lft forever preferred_lft forever
    inet6 fe80::da18:1a5c:9b1c:9a6f/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:1e:19:9d:59 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever
可以看到,在ens192網卡綁定了172.21.161.120 虛擬IP,說明工作正常。
複製代碼

  7.Nginx+Keepalived高可用測試

  關閉主節點Nginx,測試VIP是否漂移到備節點服務器。

  在Nginx Master執行 pkill nginx;

  在Nginx Backup,ip addr命令查看已成功綁定VIP

  8.訪問負載均衡器測試

  找K8s集羣中任意一個節點,使用curl查看K8s版本測試,使用VIP訪問:

複製代碼
[[email protected] ~]# curl -k https://172.21.161.120:16443/version
{
  "major": "1",
  "minor": "20",
  "gitVersion": "v1.20.7",
  "gitCommit": "132a687512d7fb058d0f5890f07d4121b3f0a2e2",
  "gitTreeState": "clean",
  "buildDate": "2021-05-12T12:32:49Z",
  "goVersion": "go1.15.12",
  "compiler": "gc",
  "platform": "linux/amd64"
}
複製代碼

  可以正確獲取到K8s版本信息,說明負載均衡器搭建正常。該請求數據流程:curl -> vip(nginx) -> apiserver

  通過查看Nginx日誌也可以看到轉發apiserver IP:

複製代碼
[[email protected] .kube]# tail -f  /var/log/nginx/k8s-access.log 
172.21.161.110 172.21.161.110:6443 - [13/Jun/2021:11:56:31 +0800] 200 2138
172.21.161.110 172.21.161.111:6443 - [13/Jun/2021:12:01:37 +0800] 200 1711
172.21.161.115 172.21.161.110:6443 - [13/Jun/2021:19:04:08 +0800] 200 1172
172.21.161.115 172.21.161.111:6443 - [13/Jun/2021:19:05:39 +0800] 200 3596
172.21.161.116 172.21.161.110:6443 - [13/Jun/2021:19:06:22 +0800] 200 1173
172.21.161.116 172.21.161.110:6443 - [13/Jun/2021:19:06:28 +0800] 200 1174
172.21.161.116 172.21.161.111:6443 - [13/Jun/2021:19:07:59 +0800] 200 3020
複製代碼

  到此還沒結束,還有下面最關鍵的一步。

 

7.3 修改所有Worker Node連接LB VIP

  試想下,雖然我們增加了Master2 Node和負載均衡器,但是我們是從單Master架構擴容的,也就是說目前所有的Worker Node組件連接都還是Master01 ,如果不改爲連接VIP走負載均衡器,那麼Master還是單點故障。

  因此接下來就是要改所有Worker Node(kubectl get node命令查看到的節點)組件配置文件,由原來172.21.161.110修改爲172.21.161.120(VIP)。

  在所有Worker Node執行:

sed -i 's#172.21.161.110:6443#172.21.161.120:16443#' /opt/kubernetes/cfg/*

  準確來說,上述命令只適合在純node節點上使用,如果master01部署了node,那麼也會有上述IP,所以爲了更精確,下面指出具體哪幾個配置文件需要更改。

[[email protected] cfg]#  grep 172.21.161.120 /opt/kubernetes/cfg/*
/opt/kubernetes/cfg/bootstrap.kubeconfig:    server: https://172.21.161.120:16443
/opt/kubernetes/cfg/kubelet.kubeconfig:    server: https://172.21.161.120:16443
/opt/kubernetes/cfg/kube-proxy.kubeconfig:    server: https://172.21.161.120:16443

  當然/root/.kube/config裏面也需要修改。

  最後將服務重啓

systemctl restart kubelet kube-proxy

 

8.將Master增加worker node節點

  當然,在一般情況下,master上也有kubelet等一些進行,用來部署一些系統級別pod,但是前面爲了讓部署的步驟拆分的更爲細緻,所以,每臺機器部署不同的角色,這裏將Master上增加worker組件。和新增一臺worker node區別不大。

  1.拷貝已部署好的Node相關文件到新節點

  在node節點將Worker Node涉及文件拷貝到master01

#node01節點操作
scp -r /opt/kubernetes/ [email protected]:/opt
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service [email protected]:/usr/lib/systemd/system

  2.刪除kubelet證書和kubeconfig文件

rm -rf /opt/kubernetes/cfg/kubelet.kubeconfig
rm -rf /opt/kubernetes/ssl/kubelet-client-*

  注:這幾個文件是證書申請審批後自動生成的,每個Node不同,必須刪除

  3.修改主機名

vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=master01

vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: master01

  4.啓動並設置開機啓動

systemctl daemon-reload
systemctl start kubelet kube-proxy
systemctl enable kubelet kube-proxy

  5.在Master上批准新Node kubelet證書申請

複製代碼
# 查看證書請求
kubectl get csr
NAME                                   AGE   SIGNERNAME                              REQUESTOR           CONDITION
node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro   89s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 授權請求
kubectl certificate approve node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro
複製代碼

  6.查看Node狀態

[[email protected] ~]# kubectl get node
NAME       STATUS   ROLES    AGE     VERSION
master01   Ready    <none>   4h37m   v1.20.7
master02   Ready    <none>   4h32m   v1.20.7
node01     Ready    <none>   15h     v1.20.7
node02     Ready    <none>   15h     v1.20.7

  多臺master也一樣

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