二進位制部署k8s-1.12.0
一、前置知識點
1.1 生產環境部署K8s叢集的兩種方式
- kubeadm
Kubeadm是一個K8s部署工具,提供kubeadm init和kubeadm join,用於快速部署Kubernetes叢集。
- 二進位制包
從github下載發行版的二進位制包,手動部署每個元件,組成Kubernetes叢集。
小結:Kubeadm降低部署門檻,但遮蔽了很多細節,遇到問題很難排查。如果想更容易可控,推薦使用二進位制包部署Kubernetes叢集,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 準備環境
伺服器要求:
- 建議最小硬體配置:2核CPU、2G記憶體、30G硬碟
- 伺服器最好可以訪問外網,會有從網上拉取映象需求,如果伺服器不能上網,需要提前下載對應映象並匯入節點
軟體環境:
軟體 |
版本 |
作業系統 |
CentOS7.x_x64 (mini) |
容器引擎 |
Docker CE 19 |
Kubernetes |
Kubernetes v1.20 |
伺服器整體規劃:
角色 |
IP |
元件 |
k8s-master1 |
192.168.31.71 |
kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker,etcd, nginx,keepalived |
k8s-master2 |
192.168.31.74 |
kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker, nginx,keepalived |
k8s-node1 |
192.168.31.72 |
kubelet,kube-proxy,docker,etcd |
k8s-node2 |
192.168.31.73 |
kubelet,kube-proxy,docker,etcd |
負載均衡器IP |
192.168.31.88 (VIP) |
|
須知:考慮到有些朋友電腦配置較低,一次性開四臺機器會跑不動,所以搭建這套K8s高可用叢集分兩部分實施,先部署一套單Master架構(3臺),再擴容為多Master架構(4臺或6臺),順便再熟悉下Master擴容流程。
單Master架構圖:
單Master伺服器規劃:
角色 |
IP |
元件 |
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 作業系統初始化配置
# 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
# 根據規劃設定主機名
hostnamectl set-hostname <hostname>
# 在master新增hosts
cat >> /etc/hosts << EOF
192.168.31.71 k8s-master1
192.168.31.72 k8s-node1
192.168.31.73 k8s-node2
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 -y
ntpdate time.windows.com
二、部署Etcd叢集
Etcd 是一個分散式鍵值儲存系統,Kubernetes使用Etcd進行資料儲存,所以先準備一個Etcd資料庫,為解決Etcd單點故障,應採用叢集方式部署,這裡使用3臺組建叢集,可容忍1臺機器故障,當然,你也可以使用5臺組建叢集,可容忍2臺機器故障。
節點名稱 |
IP |
etcd-1 |
192.168.31.71 |
etcd-2 |
192.168.31.72 |
etcd-3 |
192.168.31.73 |
注:為了節省機器,這裡與K8s節點機器複用。也可以獨立於k8s叢集之外部署,只要apiserver能連線到就行。
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檔案生成證書,相比openssl更方便使用。
找任意一臺伺服器操作,這裡用Master節點。
wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo
2.2 生成Etcd證書
1. 自簽證書頒發機構(CA)
建立工作目錄:
mkdir -p ~/TLS/{etcd,k8s}
cd ~/TLS/etcd
自籤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
生成證書:
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
會生成ca.pem和ca-key.pem檔案。
2. 使用自籤CA簽發Etcd HTTPS證書
建立證書申請檔案:
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:上述檔案hosts欄位中IP為所有etcd節點的叢集內部通訊IP,一個都不能少!為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檔案。
2.3 從Github下載二進位制檔案
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叢集
以下在節點1上操作,為簡化操作,待會將節點1生成的所有檔案拷貝到節點2和節點3.
1. 建立工作目錄並解壓二進位制包
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. 建立etcd配置檔案
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
- ETCD_NAME:節點名稱,叢集中唯一
- ETCD_DATA_DIR:資料目錄
- ETCD_LISTEN_PEER_URLS:叢集通訊監聽地址
- ETCD_LISTEN_CLIENT_URLS:客戶端訪問監聽地址
- ETCD_INITIAL_ADVERTISE_PEERURLS:叢集通告地址
- ETCD_ADVERTISE_CLIENT_URLS:客戶端通告地址
- ETCD_INITIAL_CLUSTER:叢集節點地址
- ETCD_INITIALCLUSTER_TOKEN:叢集Token
- ETCD_INITIALCLUSTER_STATE:加入叢集的當前狀態,new是新叢集,existing表示加入已有叢集
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. 拷貝剛才生成的證書
把剛才生成的證書拷貝到配置檔案中的路徑:
cp ~/TLS/etcd/ca*pem ~/TLS/etcd/server*pem /opt/etcd/ssl/
5. 啟動並設定開機啟動
systemctl daemon-reload
systemctl start etcd
systemctl enable etcd
6. 將上面節點1所有生成的檔案拷貝到節點2和節點3
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配置檔案中的節點名稱和當前伺服器IP:
vi /opt/etcd/cfg/etcd.conf
#[Member]
ETCD_NAME="etcd-1" # 修改此處,節點2改為etcd-2,節點3改為etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.71:2380" # 修改此處為當前伺服器IP
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379" # 修改此處為當前伺服器IP
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380" # 修改此處為當前伺服器IP
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379" # 修改此處為當前伺服器IP
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"
最後啟動etcd並設定開機啟動,同上。
7. 檢視叢集狀態
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://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379" endpoint health --write-out=table
+----------------------------+--------+-------------+-------+
| ENDPOINT | HEALTH | TOOK | ERROR |
+----------------------------+--------+-------------+-------+
| https://192.168.31.71:2379 | true | 10.301506ms | |
| https://192.168.31.73:2379 | true | 12.87467ms | |
| https://192.168.31.72:2379 | true | 13.225954ms | |
+----------------------------+--------+-------------+-------+
如果輸出上面資訊,就說明叢集部署成功。
如果有問題第一步先看日誌:/var/log/message 或 journalctl -u etcd
三、安裝Docker
這裡使用Docker作為容器引擎,也可以換成別的,例如containerd
下載地址:https://download.docker.com/linux/static/stable/x86_64/docker-19.03.9.tgz
以下在所有節點操作。這裡採用二進位制安裝,用yum安裝也一樣。
3.1 解壓二進位制包
tar zxvf docker-19.03.9.tgz
mv docker/* /usr/bin
3.2 systemd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 建立配置檔案
mkdir /etc/docker
cat > /etc/docker/daemon.json << EOF
{
"registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF
- registry-mirrors 阿里雲映象加速器
3.4 啟動並設定開機啟動
systemctl daemon-reload
systemctl start docker
systemctl enable docker
四、部署Master Node
4.1 生成kube-apiserver證書
1. 自簽證書頒發機構(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
生成證書:
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
會生成ca.pem和ca-key.pem檔案。
2. 使用自籤CA簽發kube-apiserver HTTPS證書
建立證書申請檔案:
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",
"192.168.31.74",
"192.168.31.88",
"kubernetes",
"kubernetes.default",
"kubernetes.default.svc",
"kubernetes.default.svc.cluster",
"kubernetes.default.svc.cluster.local"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing",
"O": "k8s",
"OU": "System"
}
]
}
EOF
注:上述檔案hosts欄位中IP為所有Master/LB/VIP IP,一個都不能少!為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檔案。
4.2 從Github下載二進位制檔案
下載地址: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.20.md
注:開啟連結你會發現裡面有很多包,下載一個server包就夠了,包含了Master和Worker Node二進位制檔案。
4.3 解壓二進位制包
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}
tar zxvf kubernetes-server-linux-amd64.tar.gz
cd kubernetes/server/bin
cp kube-apiserver kube-scheduler kube-controller-manager /opt/kubernetes/bin
cp kubectl /usr/bin/
4.4 部署kube-apiserver
1. 建立配置檔案
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.csv \\
--service-node-port-range=30000-32767 \\
--kubelet-client-certificate=/opt/kubernetes/ssl/server.pem \\
--kubelet-client-key=/opt/kubernetes/ssl/server-key.pem \\
--tls-cert-file=/opt/kubernetes/ssl/server.pem \\
--tls-private-key-file=/opt/kubernetes/ssl/server-key.pem \\
--client-ca-file=/opt/kubernetes/ssl/ca.pem \\
--service-account-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--service-account-issuer=api \\
--service-account-signing-key-file=/opt/kubernetes/ssl/server-key.pem \\
--etcd-cafile=/opt/etcd/ssl/ca.pem \\
--etcd-certfile=/opt/etcd/ssl/server.pem \\
--etcd-keyfile=/opt/etcd/ssl/server-key.pem \\
--requestheader-client-ca-file=/opt/kubernetes/ssl/ca.pem \\
--proxy-client-cert-file=/opt/kubernetes/ssl/server.pem \\
--proxy-client-key-file=/opt/kubernetes/ssl/server-key.pem \\
--requestheader-allowed-names=kubernetes \\
--requestheader-extra-headers-prefix=X-Remote-Extra- \\
--requestheader-group-headers=X-Remote-Group \\
--requestheader-username-headers=X-Remote-User \\
--enable-aggregator-routing=true \\
--audit-log-maxage=30 \\
--audit-log-maxbackup=3 \\
--audit-log-maxsize=100 \\
--audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
EOF
注:上面兩個\ \ 第一個是轉義符,第二個是換行符,使用轉義符是為了使用EOF保留換行符。
- --logtostderr:啟用日誌
- ---v:日誌等級
- --log-dir:日誌目錄
- --etcd-servers:etcd叢集地址
- --bind-address:監聽地址
- --secure-port:https安全埠
- --advertise-address:叢集通告地址
- --allow-privileged:啟用授權
- --service-cluster-ip-range:Service虛擬IP地址段
- --enable-admission-plugins:准入控制模組
- --authorization-mode:認證授權,啟用RBAC授權和節點自管理
- --enable-bootstrap-token-auth:啟用TLS bootstrap機制
- --token-auth-file:bootstrap token檔案
- --service-node-port-range:Service nodeport型別預設分配埠範圍
- --kubelet-client-xxx:apiserver訪問kubelet客戶端證書
- --tls-xxx-file:apiserver https證書
- 1.20版本必須加的引數:--service-account-issuer,--service-account-signing-key-file
- --etcd-xxxfile:連線Etcd叢集證書
- --audit-log-xxx:審計日誌
- 啟動聚合層相關配置:--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. 拷貝剛才生成的證書
把剛才生成的證書拷貝到配置檔案中的路徑:
cp ~/TLS/k8s/ca*pem ~/TLS/k8s/server*pem /opt/kubernetes/ssl/
3. 啟用 TLS Bootstrapping 機制
TLS Bootstraping:Master apiserver啟用TLS認證後,Node節點kubelet和kube-proxy要與kube-apiserver進行通訊,必須使用CA簽發的有效證書才可以,當Node節點很多時,這種客戶端證書頒發需要大量工作,同樣也會增加叢集擴充套件複雜度。為了簡化流程,Kubernetes引入了TLS bootstraping機制來自動頒發客戶端證書,kubelet會以一個低許可權使用者自動向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:
建立上述配置檔案中token檔案:
cat > /opt/kubernetes/cfg/token.csv << EOF
c47ffb939f5ca36231d9e3121a252940,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF
格式:token,使用者名稱,UID,使用者組
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
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. 啟動並設定開機啟動
systemctl daemon-reload
systemctl start kube-apiserver
systemctl enable kube-apiserver
4.5 部署kube-controller-manager
1. 建立配置檔案
cat > /opt/kubernetes/cfg/kube-controller-manager.conf << EOF
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--leader-elect=true \\
--kubeconfig=/opt/kubernetes/cfg/kube-controller-manager.kubeconfig \\
--bind-address=127.0.0.1 \\
--allocate-node-cidrs=true \\
--cluster-cidr=10.244.0.0/16 \\
--service-cluster-ip-range=10.0.0.0/24 \\
--cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem \\
--cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--root-ca-file=/opt/kubernetes/ssl/ca.pem \\
--service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--cluster-signing-duration=87600h0m0s"
EOF
- --kubeconfig:連線apiserver配置檔案
- --leader-elect:當該元件啟動多個時,自動選舉(HA)
- --cluster-signing-cert-file/--cluster-signing-key-file:自動為kubelet頒發證書的CA,與apiserver保持一致
2. 生成kubeconfig檔案
生成kube-controller-manager證書:
# 切換工作目錄
cd ~/TLS/k8s
# 建立證書請求檔案
cat > kube-controller-manager-csr.json << EOF
{
"CN": "system:kube-controller-manager",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing",
"O": "system:masters",
"OU": "System"
}
]
}
EOF
# 生成證書
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
生成kubeconfig檔案(以下是shell命令,直接在終端執行):
KUBE_CONFIG="/opt/kubernetes/cfg/kube-controller-manager.kubeconfig"
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=${KUBE_CONFIG}
kubectl config set-credentials kube-controller-manager \
--client-certificate=./kube-controller-manager.pem \
--client-key=./kube-controller-manager-key.pem \
--embed-certs=true \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
--cluster=kubernetes \
--user=kube-controller-manager \
--kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
3. 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
4. 啟動並設定開機啟動
systemctl daemon-reload
systemctl start kube-controller-manager
systemctl enable kube-controller-manager
4.6 部署kube-scheduler
1. 建立配置檔案
cat > /opt/kubernetes/cfg/kube-scheduler.conf << EOF
KUBE_SCHEDULER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--leader-elect \\
--kubeconfig=/opt/kubernetes/cfg/kube-scheduler.kubeconfig \\
--bind-address=127.0.0.1"
EOF
- --kubeconfig:連線apiserver配置檔案
- --leader-elect:當該元件啟動多個時,自動選舉(HA)
2. 生成kubeconfig檔案
生成kube-scheduler證書:
# 切換工作目錄
cd ~/TLS/k8s
# 建立證書請求檔案
cat > kube-scheduler-csr.json << EOF
{
"CN": "system:kube-scheduler",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing",
"O": "system:masters",
"OU": "System"
}
]
}
EOF
# 生成證書
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-scheduler-csr.json | cfssljson -bare kube-scheduler
生成kubeconfig檔案:
KUBE_CONFIG="/opt/kubernetes/cfg/kube-scheduler.kubeconfig"
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_CONFIG}
kubectl config set-credentials kube-scheduler \
--client-certificate=./kube-scheduler.pem \
--client-key=./kube-scheduler-key.pem \
--embed-certs=true \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
--cluster=kubernetes \
--user=kube-scheduler \
--kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
3. systemd管理scheduler
cat > /usr/lib/systemd/system/kube-scheduler.service << EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-scheduler.conf
ExecStart=/opt/kubernetes/bin/kube-scheduler \$KUBE_SCHEDULER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
4. 啟動並設定開機啟動
systemctl daemon-reload
systemctl start kube-scheduler
systemctl enable kube-scheduler
5. 檢視叢集狀態
生成kubectl連線叢集的證書:
cat > admin-csr.json <<EOF
{
"CN": "admin",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"L": "BeiJing",
"ST": "BeiJing",
"O": "system:masters",
"OU": "System"
}
]
}
EOF
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin
生成kubeconfig檔案:
mkdir /root/.kube
KUBE_CONFIG="/root/.kube/config"
KUBE_APISERVER="https://192.168.31.71:6443"
kubectl config set-cluster kubernetes \
--certificate-authority=/opt/kubernetes/ssl/ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials cluster-admin \
--client-certificate=./admin.pem \
--client-key=./admin-key.pem \
--embed-certs=true \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
--cluster=kubernetes \
--user=cluster-admin \
--kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
通過kubectl工具檢視當前叢集元件狀態:
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"}
如上輸出說明Master節點元件執行正常。
6. 授權kubelet-bootstrap使用者允許請求證書
kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap
五、部署Worker Node
下面還是在Master Node上操作,即同時作為Worker Node
5.1 建立工作目錄並拷貝二進位制檔案
在所有worker node建立工作目錄:
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}
從master節點拷貝:
cd kubernetes/server/bin
cp kubelet kube-proxy /opt/kubernetes/bin # 本地拷貝
5.2 部署kubelet
1. 建立配置檔案
cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-master1 \\
--network-plugin=cni \\
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \\
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \\
--config=/opt/kubernetes/cfg/kubelet-config.yml \\
--cert-dir=/opt/kubernetes/ssl \\
--pod-infra-container-image=lizhenliang/pause-amd64:3.0"
EOF
- --hostname-override:顯示名稱,叢集中唯一
- --network-plugin:啟用CNI
- --kubeconfig:空路徑,會自動生成,後面用於連線apiserver
- --bootstrap-kubeconfig:首次啟動向apiserver申請證書
- --config:配置引數檔案
- --cert-dir:kubelet證書生成目錄
- --pod-infra-container-image:管理Pod網路容器的映象
2. 配置引數檔案
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kubelet初次加入叢集引導kubeconfig檔案
KUBE_CONFIG="/opt/kubernetes/cfg/bootstrap.kubeconfig"
KUBE_APISERVER="https://192.168.31.71:6443" # apiserver IP:PORT
TOKEN="c47ffb939f5ca36231d9e3121a252940" # 與token.csv裡保持一致
# 生成 kubelet bootstrap kubeconfig 配置檔案
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}
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. 啟動並設定開機啟動
systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet
5.3 批准kubelet證書申請並加入叢集
# 檢視kubelet證書請求
kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A 6m3s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
# 批准申請
kubectl certificate approve node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A
# 檢視節點
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 NotReady <none> 7s v1.18.3
注:由於網路外掛還沒有部署,節點會沒有準備就緒 NotReady
5.4 部署kube-proxy
1. 建立配置檔案
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. 配置引數檔案
cat > /opt/kubernetes/cfg/kube-proxy-config.yml << EOF
kind: KubeProxyConfiguration
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 0.0.0.0
metricsBindAddress: 0.0.0.0:10249
clientConnection:
kubeconfig: /opt/kubernetes/cfg/kube-proxy.kubeconfig
hostnameOverride: k8s-master1
clusterCIDR: 10.244.0.0/16
EOF
3. 生成kube-proxy.kubeconfig檔案
# 切換工作目錄
cd ~/TLS/k8s
# 建立證書請求檔案
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
生成kubeconfig檔案:
KUBE_CONFIG="/opt/kubernetes/cfg/kube-proxy.kubeconfig"
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_CONFIG}
kubectl config set-credentials kube-proxy \
--client-certificate=./kube-proxy.pem \
--client-key=./kube-proxy-key.pem \
--embed-certs=true \
--kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
--cluster=kubernetes \
--user=kube-proxy \
--kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
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. 啟動並設定開機啟動
systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy
5.5 部署網路元件
Calico是一個純三層的資料中心網路方案,是目前Kubernetes主流的網路方案。
部署Calico:
kubectl apply -f calico.yaml
kubectl get pods -n kube-system
等Calico Pod都Running,節點也會準備就緒:
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master Ready <none> 37m v1.20.4
5.6 授權apiserver訪問kubelet
應用場景:例如kubectl logs
cat > apiserver-to-kubelet-rbac.yaml << EOF
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
annotations:
rbac.authorization.kubernetes.io/autoupdate: "true"
labels:
kubernetes.io/bootstrapping: rbac-defaults
name: system:kube-apiserver-to-kubelet
rules:
- apiGroups:
- ""
resources:
- nodes/proxy
- nodes/stats
- nodes/log
- nodes/spec
- nodes/metrics
- pods/log
verbs:
- "*"
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: system:kube-apiserver
namespace: ""
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: system:kube-apiserver-to-kubelet
subjects:
- apiGroup: rbac.authorization.k8s.io
kind: User
name: kubernetes
EOF
kubectl apply -f apiserver-to-kubelet-rbac.yaml
5.7 新增加Worker Node
1. 拷貝已部署好的Node相關檔案到新節點
在Master節點將Worker Node涉及檔案拷貝到新節點192.168.31.72/73
scp -r /opt/kubernetes [email protected]:/opt/
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service [email protected]:/usr/lib/systemd/system
scp /opt/kubernetes/ssl/ca.pem [email protected]:/opt/kubernetes/ssl
2. 刪除kubelet證書和kubeconfig檔案
rm -f /opt/kubernetes/cfg/kubelet.kubeconfig
rm -f /opt/kubernetes/ssl/kubelet*
注:這幾個檔案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=k8s-node1
vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-node1
4. 啟動並設定開機啟動
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
# 檢視證書請求
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
6. 檢視Node狀態
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready <none> 47m v1.20.4
k8s-node1 Ready <none> 6m49s v1.20.4
Node2(192.168.31.73 )節點同上。記得修改主機名!
六、部署Dashboard和CoreDNS
6.1 部署Dashboard
kubectl apply -f kubernetes-dashboard.yaml
# 檢視部署
kubectl get pods,svc -n kubernetes-dashboard
訪問地址:https://NodeIP:30001
建立service account並繫結預設cluster-admin管理員叢集角色:
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登入Dashboard。
6.2 部署CoreDNS
CoreDNS用於叢集內部Service名稱解析。
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:
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
解析沒問題。
至此一個單Master叢集就搭建完成了!這個環境就足以滿足學習實驗了,如果你的伺服器配置較高,可繼續擴容多Master叢集!
七、擴容多Master(高可用架構)
Kubernetes作為容器集群系統,通過健康檢查+重啟策略實現了Pod故障自我修復能力,通過排程演算法實現將Pod分散式部署,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叢集,高可用性還應包含以下兩個層面的考慮:Etcd資料庫的高可用性和Kubernetes Master元件的高可用性。 而Etcd我們已經採用3個節點組建叢集實現高可用,本節將對Master節點高可用進行說明和實施。
Master節點扮演著總控中心的角色,通過不斷與工作節點上的Kubelet和kube-proxy進行通訊來維護整個叢集的健康工作狀態。如果Master節點故障,將無法使用kubectl工具或者API做任何叢集管理。
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元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元件,而該元件是以HTTP API提供服務,因此對他高可用與Web伺服器類似,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 Node
現在需要再增加一臺新伺服器,作為Master2 Node,IP是192.168.31.74。
為了節省資源你也可以將之前部署好的Worker Node1複用為Master2 Node角色(即部署Master元件)
Master2 與已部署的Master1所有操作一致。所以我們只需將Master1所有K8s檔案拷貝過來,再修改下伺服器IP和主機名啟動即可。
1. 安裝Docker
scp /usr/bin/docker* [email protected]:/usr/bin
scp /usr/bin/runc [email protected]:/usr/bin
scp /usr/bin/containerd* [email protected]:/usr/bin
scp /usr/lib/systemd/system/docker.service [email protected]:/usr/lib/systemd/system
scp -r /etc/docker [email protected]:/etc
# 在Master2啟動Docker
systemctl daemon-reload
systemctl start docker
systemctl enable docker
2. 建立etcd證書目錄
在Master2建立etcd證書目錄:
mkdir -p /opt/etcd/ssl
3. 拷貝檔案(Master1操作)
拷貝Master1上所有K8s檔案和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 ~/.kube [email protected]:~
4. 刪除證書檔案
刪除kubelet證書和kubeconfig檔案:
rm -f /opt/kubernetes/cfg/kubelet.kubeconfig
rm -f /opt/kubernetes/ssl/kubelet*
5. 修改配置檔案IP和主機名
修改apiserver、kubelet和kube-proxy配置檔案為本地IP:
vi /opt/kubernetes/cfg/kube-apiserver.conf
...
--bind-address=192.168.31.74 \
--advertise-address=192.168.31.74 \
...
vi /opt/kubernetes/cfg/kube-controller-manager.kubeconfig
server: https://192.168.31.74:6443
vi /opt/kubernetes/cfg/kube-scheduler.kubeconfig
server: https://192.168.31.74:6443
vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-master2
vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-master2
vi ~/.kube/config
...
server: https://192.168.31.74:6443
6. 啟動設定開機啟動
systemctl daemon-reload
systemctl start kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxy
systemctl enable kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxy
7. 檢視叢集狀態
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"}
8. 批准kubelet證書申請
# 檢視證書請求
kubectl get csr
NAME AGE SIGNERNAME REQUESTOR CONDITION
node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU 85m kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending
# 授權請求
kubectl certificate approve node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU
# 檢視Node
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready <none> 34h v1.20.4
k8s-master2 Ready <none> 2m v1.20.4
k8s-node1 Ready <none> 33h v1.20.4
k8s-node2 Ready <none> 33h v1.20.4
如果你在學習中遇到問題或者文件有誤可聯絡阿良~ 微信: k8init
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服務和反向代理伺服器,這裡用四層實現對apiserver實現負載均衡。
- Keepalived是一個主流高可用軟體,基於VIP繫結實現伺服器雙機熱備,在上述拓撲中,Keepalived主要根據Nginx執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會自動繫結在Nginx備節點,從而保證VIP一直可用,實現Nginx高可用。
注1:為了節省機器,這裡與K8s Master節點機器複用。也可以獨立於k8s叢集之外部署,只要nginx與apiserver能通訊就行。
注2:如果你是在公有云上,一般都不支援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. 安裝軟體包(主/備)
yum install epel-release -y
yum install nginx keepalived -y
2. Nginx配置檔案(主/備一樣)
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,為兩臺Master apiserver元件提供負載均衡
stream {
log_format main '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent';
access_log /var/log/nginx/k8s-access.log main;
upstream k8s-apiserver {
server 192.168.31.71:6443; # Master1 APISERVER IP:PORT
server 192.168.31.74:6443; # Master2 APISERVER IP:PORT
}
server {
listen 16443; # 由於nginx與master節點複用,這個監聽埠不能是6443,否則會衝突
proxy_pass k8s-apiserver;
}
}
http {
log_format main '$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
3. keepalived配置檔案(Nginx Master)
cat > /etc/keepalived/keepalived.conf << EOF
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id NGINX_MASTER
}
vrrp_script check_nginx {
script "/etc/keepalived/check_nginx.sh"
}
vrrp_instance VI_1 {
state MASTER
interface ens33 # 修改為實際網絡卡名
virtual_router_id 51 # VRRP 路由 ID例項,每個例項是唯一的
priority 100 # 優先順序,備伺服器設定 90
advert_int 1 # 指定VRRP 心跳包通告間隔時間,預設1秒
authentication {
auth_type PASS
auth_pass 1111
}
# 虛擬IP
virtual_ipaddress {
192.168.31.88/24
}
track_script {
check_nginx
}
}
EOF
- vrrp_script:指定檢查nginx工作狀態指令碼(根據nginx狀態判斷是否故障轉移)
- virtual_ipaddress:虛擬IP(VIP)
準備上述配置檔案中檢查nginx執行狀態的指令碼:
cat > /etc/keepalived/check_nginx.sh << "EOF"
#!/bin/bash
count=$(ss -antp |grep 16443 |egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
exit 1
else
exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh
4. keepalived配置檔案(Nginx Backup)
cat > /etc/keepalived/keepalived.conf << EOF
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id NGINX_BACKUP
}
vrrp_script check_nginx {
script "/etc/keepalived/check_nginx.sh"
}
vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51 # VRRP 路由 ID例項,每個例項是唯一的
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.31.88/24
}
track_script {
check_nginx
}
}
EOF
準備上述配置檔案中檢查nginx執行狀態的指令碼:
cat > /etc/keepalived/check_nginx.sh << "EOF"
#!/bin/bash
count=$(ss -antp |grep 16443 |egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
exit 1
else
exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh
注:keepalived根據指令碼返回狀態碼(0為工作正常,非0不正常)判斷是否故障轉移。
5. 啟動並設定開機啟動
systemctl daemon-reload
systemctl start nginx keepalived
systemctl enable nginx keepalived
6. 檢視keepalived工作狀態
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: 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網絡卡綁定了192.168.31.88 虛擬IP,說明工作正常。
7. Nginx+Keepalived高可用測試
關閉主節點Nginx,測試VIP是否漂移到備節點伺服器。
在Nginx Master執行 pkill nginx;
在Nginx Backup,ip addr命令檢視已成功繫結VIP。
8. 訪問負載均衡器測試
找K8s叢集中任意一個節點,使用curl檢視K8s版本測試,使用VIP訪問:
curl -k https://192.168.31.88:16443/version
{
"major": "1",
"minor": "20",
"gitVersion": "v1.20.4",
"gitCommit": "e87da0bd6e03ec3fea7933c4b5263d151aafd07c",
"gitTreeState": "clean",
"buildDate": "2021-02-18T16:03:00Z",
"goVersion": "go1.15.8",
"compiler": "gc",
"platform": "linux/amd64"
}
可以正確獲取到K8s版本資訊,說明負載均衡器搭建正常。該請求資料流程:curl -> vip(nginx) -> apiserver
通過檢視Nginx日誌也可以看到轉發apiserver IP:
tail /var/log/nginx/k8s-access.log -f
192.168.31.71 192.168.31.71:6443 - [02/Apr/2021:19:17:57 +0800] 200 423
192.168.31.71 192.168.31.72:6443 - [02/Apr/2021:19:18:50 +0800] 200 423
到此還沒結束,還有下面最關鍵的一步。
7.3 修改所有Worker Node連線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元件連線都還是Master1 Node,如果不改為連線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命令檢視到的節點)元件配置檔案,由原來192.168.31.71修改為192.168.31.88(VIP)。
在所有Worker Node執行:
sed -i 's#192.168.31.71:6443#192.168.31.88:16443#' /opt/kubernetes/cfg/*
systemctl restart kubelet kube-proxy
檢查節點狀態:
kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master1 Ready <none> 32d v1.20.4
k8s-master2 Ready <none> 10m v1.20.4
k8s-node1 Ready <none> 31d v1.20.4
k8s-node2 Ready <none> 31d v1.20.4