前面我們安裝了一個簡單的kubernetes叢集,選用了1個master節點和三個node節點。etcd也沒有安裝成叢集.
這次我們安裝一個3個master節點+etcd叢集的kubernetes叢集.
節點規劃
本次選用三個master節點,三個node節點來安 裝k8s叢集。
etcd叢集安裝在master節點上.
并準備一個虛拟ip來做keepalived。
節點 | IP |
---|---|
M0 | 10.xx.xx.xx |
M1 | |
M2 | |
N0 | |
N1 | |
N2 |
virtual_ipaddress: 10.xx.xx.xx
叢集啟動前的準備(請用root使用者執行)
節點準備工作(在每台機器上執行)
包括修改主機名,關閉防火牆等操作。
k8s叢集會識别主機名字,確定每個主機名設為不同值。
關閉防火牆是為了避免不必要的網絡問題。
# ${hostname}變量請替換成規劃的主機名,比如M0, N0, N1
sudo hostnamectl set-hostname ${hostname}
systemctl stop firewalld
systemctl disable firewalld
setenforce 0
sed -i -re '/^\s*SELINUX=/s/^/#/' -e '$i\\SELINUX=disabled' /etc/selinux/config
建立ssh的互信,友善後面傳檔案什麼的。可以使用
ssh-copy-id
指令快速建立,也可以自己手動建立。這個網上教程很多,自己搜一下
安裝docker(在每台機器上執行)
yum install docker -y
systemctl enable docker && systemctl start docker
修改docker的log driver為
json-file
,這個不影響安裝,隻是為了後期安裝efk日志收集系統友善。
docker info
可以檢視目前log driver,centos7預設使用journald.
不同版本的docker可能修改方式不一樣,最新官網文檔是修改
/etc/docker/daemon.json
檔案,我安裝的版本是1.12.6,按如下方式修改。
vim /etc/sysconfig/docker
# 修改為如下,然後重新開機docker OPTIONS='--selinux-enabled --log-driver=json-file --signature-verification=false' systemctl restart docker
安裝kubeadm, kubelet, kubectl(每台機器上執行)
- kubeadm: 快速建立k8s叢集的工具
- kubelet: k8s的基礎元件,負責對pod和container的建立和管理,與k8s叢集master建立聯系
- kubectl: k8s的用戶端工具,用來像叢集發送命名
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
yum install -y kubelet kubeadm kubectl
官網文檔上寫一些使用者在RHEL/Centos7系統上安裝時,由于iptables被繞過導緻路由錯誤,需要在
sysctl的config檔案中将net.bridge.bridge-nf-call-iptables設定為1.
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system
啟動kubelet:
systemctl enable kubelet && systemctl start kubelet
至此,準備工作就做好了。目前每隔幾秒kubelet就會重新開機,直到收到kubeadm的指令。
是以用
systemctl status kubelet
看到kubelet沒有啟動是正常現象,可以多執行幾次檢視,就會發現kubelet處于不斷停止和重新開機的狀态.
安裝etcd叢集(在三個master節點安裝)
建立etcd CA憑證
- 安裝
和cfssl
sfssljson
curl -o /usr/local/bin/cfssl https://pkg.cfssl.org/R1.2/cfssl_linux-amd64 curl -o /usr/local/bin/cfssljson https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64 chmod +x /usr/local/bin/cfssl*
-
ssh到etcd0節點(我這裡規劃的是master0節點),執行下面指令
執行完成可以看到
檔案夾下生成了ca-config.json和ca-csr.json兩個檔案/etc/kubernetes/pki/etcd
mkdir -p /etc/kubernetes/pki/etcd cd /etc/kubernetes/pki/etcd cat >ca-config.json <<EOF { "signing": { "default": { "expiry": "43800h" }, "profiles": { "server": { "expiry": "43800h", "usages": [ "signing", "key encipherment", "server auth", "client auth" ] }, "client": { "expiry": "43800h", "usages": [ "signing", "key encipherment", "client auth" ] }, "peer": { "expiry": "43800h", "usages": [ "signing", "key encipherment", "server auth", "client auth" ] } } } } EOF cat >ca-csr.json <<EOF { "CN": "etcd", "key": { "algo": "rsa", "size": 2048 } } EOF
- 生成ca證書
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
生成etcd用戶端證書
在etcd0節點執行以下操作,會生成兩個檔案client.pem, client-key.pem
cat >client.json <<EOF
{
"CN": "client",
"key": {
"algo": "ecdsa",
"size": 256
}
}
EOF
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=client client.json | cfssljson -bare client
生成etcd的server和peer證書
- 設定PEER_NAME和PRIVATE_IP環境變量(在每台etcd機器上執行)
# 注意下面ens192是你實際網卡的名字,有可能是eth1之類的。用ip addr檢視。 export PEER_NAME=$(hostname) export PRIVATE_IP=$(ip addr show ens192 | grep -Po 'inet \K[\d.]+')
-
将剛剛在etcd上生成的CA拷貝到另外兩台etcd機器上(在兩台etch peers上執行)。
這裡需要ssh信任權限,這個在上面已經讓你建立好了。
mkdir -p /etc/kubernetes/pki/etcd cd /etc/kubernetes/pki/etcd scp root@<etcd0-ip-address>:/etc/kubernetes/pki/etcd/ca.pem . scp root@<etcd0-ip-address>:/etc/kubernetes/pki/etcd/ca-key.pem . scp root@<etcd0-ip-address>:/etc/kubernetes/pki/etcd/client.pem . scp root@<etcd0-ip-address>:/etc/kubernetes/pki/etcd/client-key.pem . scp root@<etcd0-ip-address>:/etc/kubernetes/pki/etcd/ca-config.json .
- 在所有etcd機器上執行下面指令,生成peer.pem, peer-key.pem, server.pem, server-key.pem
cfssl print-defaults csr > config.json sed -i '0,/CN/{s/example\.net/'"$PEER_NAME"'/}' config.json sed -i 's/www\.example\.net/'"$PRIVATE_IP"'/' config.json sed -i 's/example\.net/'"$PEER_NAME"'/' config.json cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=server config.json | cfssljson -bare server cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=peer config.json | cfssljson -bare peer
啟動etcd叢集(在每台etcd機器上執行)
這裡有兩種方式:在虛拟機上直接運作或在k8s上運作static pods.我這裡選用第一種,在虛拟機上直接運作.
- 安裝etcd
cd /tmp export ETCD_VERSION=v3.1.10 curl -sSL https://github.com/coreos/etcd/releases/download/${ETCD_VERSION}/etcd-${ETCD_VERSION}-linux-amd64.tar.gz | tar -xzv --strip-components=1 -C /usr/local/bin/ rm -rf etcd-$ETCD_VERSION-linux-amd64*
- 生成etcd的環境檔案,後面将會用到
touch /etc/etcd.env echo "PEER_NAME=$PEER_NAME" >> /etc/etcd.env echo "PRIVATE_IP=$PRIVATE_IP" >> /etc/etcd.env
-
建立etcd服務systemd的配置檔案
注意修改下面<etcd0-ip-address>等變量為虛拟機的真實ip位址。m0, m1等為etcd的名字
cat >/etc/systemd/system/etcd.service <<EOF [Unit] Description=etcd Documentation=https://github.com/coreos/etcd Conflicts=etcd.service Conflicts=etcd2.service [Service] EnvironmentFile=/etc/etcd.env Type=notify Restart=always RestartSec=5s LimitNOFILE=40000 TimeoutStartSec=0 ExecStart=/usr/local/bin/etcd --name ${PEER_NAME} \ --data-dir /var/lib/etcd \ --listen-client-urls https://${PRIVATE_IP}:2379 \ --advertise-client-urls https://${PRIVATE_IP}:2379 \ --listen-peer-urls https://${PRIVATE_IP}:2380 \ --initial-advertise-peer-urls https://${PRIVATE_IP}:2380 \ --cert-file=/etc/kubernetes/pki/etcd/server.pem \ --key-file=/etc/kubernetes/pki/etcd/server-key.pem \ --client-cert-auth \ --trusted-ca-file=/etc/kubernetes/pki/etcd/ca.pem \ --peer-cert-file=/etc/kubernetes/pki/etcd/peer.pem \ --peer-key-file=/etc/kubernetes/pki/etcd/peer-key.pem \ --peer-client-cert-auth \ --peer-trusted-ca-file=/etc/kubernetes/pki/etcd/ca.pem \ --initial-cluster m0=https://<etcd0-ip-address>:2380,m1=https://<etcd1-ip-address>:2380,m2=https://<etcd2-ip-address>:2380 \ --initial-cluster-token my-etcd-token \ --initial-cluster-state new [Install] WantedBy=multi-user.target EOF
- 啟動etcd叢集
systemctl daemon-reload systemctl start etcd
設定master節點的負載均衡器(keepalived,在三台master節點上執行)
- 安裝keepalived
yum install keepalived -y
- 修改配置檔案
- state: 填寫MASTER(主master節點m0)或BACKUP(其他master節點)
- interface: 填寫網卡的名字(我這裡是ens192)\
- priority: 權重,主master節點應該比其他節點高(比如m0填寫101,其他節點填寫100)
- auth_pass: 任意随機字元
- virtual_ipaddress: 應該填寫為master節點準備的虛拟ip
! Configuration File for keepalived global_defs { router_id LVS_DEVEL } vrrp_script check_apiserver { script "/etc/keepalived/check_apiserver.sh" interval 3 weight -2 fall 10 rise 2 } vrrp_instance VI_1 { state <STATE> interface <INTERFACE> virtual_router_id 51 priority <PRIORITY> authentication { auth_type PASS auth_pass 4be37dc3b4c90194d1600c483e10ad1d } virtual_ipaddress { <VIRTUAL-IP> } track_script { check_apiserver } }
-
健康檢測腳本
将下面的<VIRTUAL-IP>替換成準備的虛拟ip
#!/bin/sh errorExit() { echo "*** $*" 1>&2 exit 1 } curl --silent --max-time 2 --insecure https://localhost:6443/ -o /dev/null || errorExit "Error GET https://localhost:6443/" if ip addr | grep -q <VIRTUAL-IP>; then curl --silent --max-time 2 --insecure https://<VIRTUAL-IP>:6443/ -o /dev/null || errorExit "Error GET https://<VIRTUAL-IP>:6443/" fi
- 啟動keepalived
systemctl start keepalived
啟動k8s叢集
啟動master0節點
- 生成配置檔案:
- <private-ip>: 為master節點的IP位址
- <etcd0-ip>, <etcd1-ip>, <etcd2-ip> : etcd叢集的ip位址
- <podCIDR>:POD CIDR,k8s的pod的網絡模式。我這裡選擇flannel,即配置 為10.244.0.0/16。詳細資訊檢視 CNI network section
- 為了安裝flannel,需要在每台機器上執行
sysctl net.bridge.bridge-nf-call-iptables=1
cat >config.yaml <<EOF apiVersion: kubeadm.k8s.io/v1alpha1 kind: MasterConfiguration api: advertiseAddress: <private-ip> etcd: endpoints: - https://<etcd0-ip-address>:2379 - https://<etcd1-ip-address>:2379 - https://<etcd2-ip-address>:2379 caFile: /etc/kubernetes/pki/etcd/ca.pem certFile: /etc/kubernetes/pki/etcd/client.pem keyFile: /etc/kubernetes/pki/etcd/client-key.pem networking: podSubnet: <podCIDR> apiServerCertSANs: - <load-balancer-ip> apiServerExtraArgs: apiserver-count: "3" EOF
- 運作kubeadm
kubeadm init --config=config.yaml
啟動master1, master2節點
- 将剛剛master0生成的檔案copy到master1和master2機器
scp root@<master0-ip-address>:/etc/kubernetes/pki/ca.crt /etc/kubernetes/pki scp root@<master0-ip-address>:/etc/kubernetes/pki/ca.key /etc/kubernetes/pki scp root@<master0-ip-address>:/etc/kubernetes/pki/sa.key /etc/kubernetes/pki scp root@<master0-ip-address>:/etc/kubernetes/pki/sa.pub /etc/kubernetes/pki scp root@<master0-ip-address>:/etc/kubernetes/pki/front-proxy-ca.crt /etc/kubernetes/pki scp root@<master0-ip-address>:/etc/kubernetes/pki/front-proxy-ca.key /etc/kubernetes/pki scp -r root@<master0-ip-address>:/etc/kubernetes/pki/etcd /etc/kubernetes/pki
- 重複master0的操作,生成config.yaml,運作kubeadm.
安裝CNI網絡
這裡跟上面<podCIDR>那裡設定的要對應起來。我這裡選用的是Flannel,執行下面指令。
官網詳解
Installing a pod networkkubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.9.1/Documentation/kube-flannel.yml
加入node節點
在每台node機器上執行以下格式的指令,在master節點執行完kubeadm init後會生成下面指令,複制執行就好。
這裡統一将node加入到master0管理中。
kubeadm join --token <token> <master-ip>:<master-port> --discovery-token-ca-cert-hash sha256:<hash>
完了可以使用
kubectl get nodes
檢視叢集是否安裝完成。
本文轉自SegmentFault-
kubernetes1.9高可用叢集安裝(使用kubeadm工具)