使用kubeadm安装k8s-1.11版本多主高可用

实验环 境说明

实验架构图

lab1: etcd master haproxy keepalived 11.11.11.111 lab2: etcd master haproxy keepalived 11.11.11.112 lab3: etcd master haproxy keepalived 11.11.11.113 lab4: node 11.11.11.114 lab5: node 11.11.11.115 lab6: node 11.11.11.116 vip(loadblancer ip): 11.11.11.110 复制代码

实验使用的Vagrantfile

# -*- mode: ruby -*- # vi: set ft=ruby : ENV["LC_ALL"] = "en_US.UTF-8" Vagrant.configure("2") do |config| (1..6).each do |i| config.vm.define "lab#{i}" do |node| node.vm.box = "centos-7.4-docker-17" node.ssh.insert_key = false node.vm.hostname = "lab#{i}" node.vm.network "private_network", ip: "11.11.11.11#{i}" node.vm.provision "shell", inline: "echo hello from node #{i}" node.vm.provider "virtualbox" do |v| v.cpus = 2 v.customize ["modifyvm", :id, "--name", "lab#{i}", "--memory", "2048"] end end end end 复制代码

安装配置docker

v1.11.0版本推荐使用docker v17.03, v1.11,v1.12,v1.13, 也可以使用，再高版本的docker可能无法正常使用。 测试发现17.09无法正常使用，不能使用资源限制(内存CPU)

如下操作在所有节点操作

安装docker

# 卸载安装指定版本docker-ce yum remove -y docker-ce docker-ce-selinux container-selinux yum install -y --setopt=obsoletes=0 \ docker-ce-17.03.1.ce-1.el7.centos \ docker-ce-selinux-17.03.1.ce-1.el7.centos 复制代码

启动docker

systemctl enable docker && systemctl restart docker 复制代码

安装 kubeadm, kubelet 和 kubectl

如下操作在所有节点操作

使用阿里镜像安装

# 配置源 cat <<EOF > /etc/yum.repos.d/kubernetes.repo [kubernetes] name=Kubernetes baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64 enabled=1 gpgcheck=1 repo_gpgcheck=1 gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg EOF # 安装 yum install -y kubelet kubeadm kubectl ipvsadm 复制代码

配置系统相关参数

# 临时禁用selinux # 永久关闭 修改/etc/sysconfig/selinux文件设置 sed -i 's/SELINUX=permissive/SELINUX=disabled/' /etc/sysconfig/selinux setenforce 0 # 临时关闭swap # 永久关闭 注释/etc/fstab文件里swap相关的行 swapoff -a # 开启forward # Docker从1.13版本开始调整了默认的防火墙规则 # 禁用了iptables filter表中FOWARD链 # 这样会引起Kubernetes集群中跨Node的Pod无法通信 iptables -P FORWARD ACCEPT # 配置转发相关参数，否则可能会出错 cat <<EOF > /etc/sysctl.d/k8s.conf net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 vm.swappiness=0 EOF sysctl --system # 加载ipvs相关内核模块 # 如果重新开机，需要重新加载 modprobe ip_vs modprobe ip_vs_rr modprobe ip_vs_wrr modprobe ip_vs_sh modprobe nf_conntrack_ipv4 lsmod | grep ip_vs 复制代码

配置hosts解析

如下操作在所有节点操作

cat >>/etc/hosts<<EOF 11.11.11.111 lab1 11.11.11.112 lab2 11.11.11.113 lab3 11.11.11.114 lab4 11.11.11.115 lab5 11.11.11.116 lab6 EOF 复制代码

配置haproxy代理和keepalived

如下操作在节点lab1,lab2,lab3操作

# 拉取haproxy镜像 docker pull haproxy:1.7.8-alpine mkdir /etc/haproxy cat >/etc/haproxy/haproxy.cfg<<EOF global log 127.0.0.1 local0 err maxconn 50000 uid 99 gid 99 #daemon nbproc 1 pidfile haproxy.pid defaults mode http log 127.0.0.1 local0 err maxconn 50000 retries 3 timeout connect 5s timeout client 30s timeout server 30s timeout check 2s listen admin_stats mode http bind 0.0.0.0:1080 log 127.0.0.1 local0 err stats refresh 30s stats uri /haproxy-status stats realm Haproxy\ Statistics stats auth will:will stats hide-version stats admin if TRUE frontend k8s-https bind 0.0.0.0:8443 mode tcp #maxconn 50000 default_backend k8s-https backend k8s-https mode tcp balance roundrobin server lab1 11.11.11.111:6443 weight 1 maxconn 1000 check inter 2000 rise 2 fall 3 server lab2 11.11.11.112:6443 weight 1 maxconn 1000 check inter 2000 rise 2 fall 3 server lab3 11.11.11.113:6443 weight 1 maxconn 1000 check inter 2000 rise 2 fall 3 EOF # 启动haproxy docker run -d --name my-haproxy \ -v /etc/haproxy:/usr/local/etc/haproxy:ro \ -p 8443:8443 \ -p 1080:1080 \ --restart always \ haproxy:1.7.8-alpine # 查看日志 docker logs my-haproxy # 浏览器查看状态 http://11.11.11.111:1080/haproxy-status http://11.11.11.112:1080/haproxy-status # 拉取keepalived镜像 docker pull osixia/keepalived:1.4.4 # 启动 # 载入内核相关模块 lsmod | grep ip_vs modprobe ip_vs # 启动keepalived # eth1为本次实验11.11.11.0/24网段的所在网卡 docker run --net=host --cap-add=NET_ADMIN \ -e KEEPALIVED_INTERFACE=eth1 \ -e KEEPALIVED_VIRTUAL_IPS="#PYTHON2BASH:['11.11.11.110']" \ -e KEEPALIVED_UNICAST_PEERS="#PYTHON2BASH:['11.11.11.111','11.11.11.112','11.11.11.113']" \ -e KEEPALIVED_PASSWORD=hello \ --name k8s-keepalived \ --restart always \ -d osixia/keepalived:1.4.4 # 查看日志 # 会看到两个成为backup 一个成为master docker logs k8s-keepalived # 此时会配置 11.11.11.110 到其中一台机器 # ping测试 ping -c4 11.11.11.110 # 如果失败后清理后，重新实验 docker rm -f k8s-keepalived ip a del 11.11.11.110/32 dev eth1 复制代码

配置启动kubelet

如下操作在所有节点操作

# 配置kubelet使用国内pause镜像 # 配置kubelet的cgroups # 获取docker的cgroups DOCKER_CGROUPS=$(docker info | grep 'Cgroup' | cut -d' ' -f3) echo $DOCKER_CGROUPS cat >/etc/sysconfig/kubelet<<EOF KUBELET_EXTRA_ARGS="--cgroup-driver=$DOCKER_CGROUPS --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.1" EOF # 启动 systemctl daemon-reload systemctl enable kubelet && systemctl restart kubelet 复制代码

配置master

配置第一个master节点

如下操作在lab1节点操作

# 1.11 版本 centos 下使用 ipvs 模式会出问题 # 参考 https://github.com/kubernetes/kubernetes/issues/65461 # 生成配置文件 CP0_IP="11.11.11.111" CP0_HOSTNAME="lab1" cat >kubeadm-master.config<<EOF apiVersion: kubeadm.k8s.io/v1alpha2 kind: MasterConfiguration kubernetesVersion: v1.11.0 imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers apiServerCertSANs: - "lab1" - "lab2" - "lab3" - "11.11.11.111" - "11.11.11.112" - "11.11.11.113" - "11.11.11.110" - "127.0.0.1" api: advertiseAddress: $CP0_IP controlPlaneEndpoint: 11.11.11.110:8443 etcd: local: extraArgs: listen-client-urls: "https://127.0.0.1:2379,https://$CP0_IP:2379" advertise-client-urls: "https://$CP0_IP:2379" listen-peer-urls: "https://$CP0_IP:2380" initial-advertise-peer-urls: "https://$CP0_IP:2380" initial-cluster: "$CP0_HOSTNAME=https://$CP0_IP:2380" serverCertSANs: - $CP0_HOSTNAME - $CP0_IP peerCertSANs: - $CP0_HOSTNAME - $CP0_IP controllerManagerExtraArgs: node-monitor-grace-period: 10s pod-eviction-timeout: 10s networking: podSubnet: 10.244.0.0/16 kubeProxy: config: # mode: ipvs mode: iptables EOF # 提前拉取镜像 # 如果执行失败 可以多次执行 kubeadm config images pull --config kubeadm-master.config # 初始化 # 注意保存返回的 join 命令 kubeadm init --config kubeadm-master.config # 打包ca相关文件上传至其他master节点 cd /etc/kubernetes && tar cvzf k8s-key.tgz admin.conf pki/ca.* pki/sa.* pki/front-proxy-ca.* pki/etcd/ca.* scp k8s-key.tgz lab2:~/ scp k8s-key.tgz lab3:~/ ssh lab2 'tar xf k8s-key.tgz -C /etc/kubernetes/' ssh lab3 'tar xf k8s-key.tgz -C /etc/kubernetes/' 复制代码

配置第二个master节点

如下操作在lab2节点操作

# 1.11 版本 centos 下使用 ipvs 模式会出问题 # 参考 https://github.com/kubernetes/kubernetes/issues/65461 # 生成配置文件 CP0_IP="11.11.11.111" CP0_HOSTNAME="lab1" CP1_IP="11.11.11.112" CP1_HOSTNAME="lab2" cat >kubeadm-master.config<<EOF apiVersion: kubeadm.k8s.io/v1alpha2 kind: MasterConfiguration kubernetesVersion: v1.11.0 imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers apiServerCertSANs: - "lab1" - "lab2" - "lab3" - "11.11.11.111" - "11.11.11.112" - "11.11.11.113" - "11.11.11.110" - "127.0.0.1" api: advertiseAddress: $CP1_IP controlPlaneEndpoint: 11.11.11.110:8443 etcd: local: extraArgs: listen-client-urls: "https://127.0.0.1:2379,https://$CP1_IP:2379" advertise-client-urls: "https://$CP1_IP:2379" listen-peer-urls: "https://$CP1_IP:2380" initial-advertise-peer-urls: "https://$CP1_IP:2380" initial-cluster: "$CP0_HOSTNAME=https://$CP0_IP:2380,$CP1_HOSTNAME=https://$CP1_IP:2380" initial-cluster-state: existing serverCertSANs: - $CP1_HOSTNAME - $CP1_IP peerCertSANs: - $CP1_HOSTNAME - $CP1_IP controllerManagerExtraArgs: node-monitor-grace-period: 10s pod-eviction-timeout: 10s networking: podSubnet: 10.244.0.0/16 kubeProxy: config: # mode: ipvs mode: iptables EOF # 配置kubelet kubeadm alpha phase certs all --config kubeadm-master.config kubeadm alpha phase kubelet config write-to-disk --config kubeadm-master.config kubeadm alpha phase kubelet write-env-file --config kubeadm-master.config kubeadm alpha phase kubeconfig kubelet --config kubeadm-master.config systemctl restart kubelet # 添加etcd到集群中 CP0_IP="11.11.11.111" CP0_HOSTNAME="lab1" CP1_IP="11.11.11.112" CP1_HOSTNAME="lab2" KUBECONFIG=/etc/kubernetes/admin.conf kubectl exec -n kube-system etcd-${CP0_HOSTNAME} -- etcdctl --ca-file /etc/kubernetes/pki/etcd/ca.crt --cert-file /etc/kubernetes/pki/etcd/peer.crt --key-file /etc/kubernetes/pki/etcd/peer.key --endpoints=https://${CP0_IP}:2379 member add ${CP1_HOSTNAME} https://${CP1_IP}:2380 kubeadm alpha phase etcd local --config kubeadm-master.config # 提前拉取镜像 # 如果执行失败 可以多次执行 kubeadm config images pull --config kubeadm-master.config # 部署 kubeadm alpha phase kubeconfig all --config kubeadm-master.config kubeadm alpha phase controlplane all --config kubeadm-master.config kubeadm alpha phase mark-master --config kubeadm-master.config 复制代码

配置第三个master节点

如下操作在lab3节点操作

# 1.11 版本 centos 下使用 ipvs 模式会出问题 # 参考 https://github.com/kubernetes/kubernetes/issues/65461 # 生成配置文件 CP0_IP="11.11.11.111" CP0_HOSTNAME="lab1" CP1_IP="11.11.11.112" CP1_HOSTNAME="lab2" CP2_IP="11.11.11.113" CP2_HOSTNAME="lab3" cat >kubeadm-master.config<<EOF apiVersion: kubeadm.k8s.io/v1alpha2 kind: MasterConfiguration kubernetesVersion: v1.11.0 imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers apiServerCertSANs: - "lab1" - "lab2" - "lab3" - "11.11.11.111" - "11.11.11.112" - "11.11.11.113" - "11.11.11.110" - "127.0.0.1" api: advertiseAddress: $CP2_IP controlPlaneEndpoint: 11.11.11.110:8443 etcd: local: extraArgs: listen-client-urls: "https://127.0.0.1:2379,https://$CP2_IP:2379" advertise-client-urls: "https://$CP2_IP:2379" listen-peer-urls: "https://$CP2_IP:2380" initial-advertise-peer-urls: "https://$CP2_IP:2380" initial-cluster: "$CP0_HOSTNAME=https://$CP0_IP:2380,$CP1_HOSTNAME=https://$CP1_IP:2380,$CP2_HOSTNAME=https://$CP2_IP:2380" initial-cluster-state: existing serverCertSANs: - $CP2_HOSTNAME - $CP2_IP peerCertSANs: - $CP2_HOSTNAME - $CP2_IP controllerManagerExtraArgs: node-monitor-grace-period: 10s pod-eviction-timeout: 10s networking: podSubnet: 10.244.0.0/16 kubeProxy: config: # mode: ipvs mode: iptables EOF # 配置kubelet kubeadm alpha phase certs all --config kubeadm-master.config kubeadm alpha phase kubelet config write-to-disk --config kubeadm-master.config kubeadm alpha phase kubelet write-env-file --config kubeadm-master.config kubeadm alpha phase kubeconfig kubelet --config kubeadm-master.config systemctl restart kubelet # 添加etcd到集群中 CP0_IP="11.11.11.111" CP0_HOSTNAME="lab1" CP2_IP="11.11.11.113" CP2_HOSTNAME="lab3" KUBECONFIG=/etc/kubernetes/admin.conf kubectl exec -n kube-system etcd-${CP0_HOSTNAME} -- etcdctl --ca-file /etc/kubernetes/pki/etcd/ca.crt --cert-file /etc/kubernetes/pki/etcd/peer.crt --key-file /etc/kubernetes/pki/etcd/peer.key --endpoints=https://${CP0_IP}:2379 member add ${CP2_HOSTNAME} https://${CP2_IP}:2380 kubeadm alpha phase etcd local --config kubeadm-master.config # 提前拉取镜像 # 如果执行失败 可以多次执行 kubeadm config images pull --config kubeadm-master.config # 部署 kubeadm alpha phase kubeconfig all --config kubeadm-master.config kubeadm alpha phase controlplane all --config kubeadm-master.config kubeadm alpha phase mark-master --config kubeadm-master.config 复制代码

配置使用kubectl

如下操作在任意master节点操作

rm -rf $HOME/.kube mkdir -p $HOME/.kube sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config sudo chown $(id -u):$(id -g) $HOME/.kube/config # 查看node节点 kubectl get nodes # 只有网络插件也安装配置完成之后，才能会显示为ready状态 # 设置master允许部署应用pod，参与工作负载，现在可以部署其他系统组件 # 如 dashboard, heapster, efk等 kubectl taint nodes --all node-role.kubernetes.io/master- 复制代码

配置使用网络插件

如下操作在任意master节点操作

# 下载配置 mkdir flannel && cd flannel wget https://raw.githubusercontent.com/coreos/flannel/v0.10.0/Documentation/kube-flannel.yml # 修改配置 # 此处的ip配置要与上面kubeadm的pod-network一致 net-conf.json: | { "Network": "10.244.0.0/16", "Backend": { "Type": "vxlan" } } # 修改镜像 image: registry.cn-shanghai.aliyuncs.com/gcr-k8s/flannel:v0.10.0-amd64 # 如果Node有多个网卡的话，参考flannel issues 39701， # https://github.com/kubernetes/kubernetes/issues/39701 # 目前需要在kube-flannel.yml中使用--iface参数指定集群主机内网网卡的名称， # 否则可能会出现dns无法解析。容器无法通信的情况，需要将kube-flannel.yml下载到本地， # flanneld启动参数加上--iface=<iface-name> containers: - name: kube-flannel image: registry.cn-shanghai.aliyuncs.com/gcr-k8s/flannel:v0.10.0-amd64 command: - /opt/bin/flanneld args: - --ip-masq - --kube-subnet-mgr - --iface=eth1 # 启动 kubectl apply -f kube-flannel.yml # 查看 kubectl get pods --namespace kube-system kubectl get svc --namespace kube-system 复制代码

配置node节点加入集群

如下操作在所有node节点操作

# 此命令为初始化master成功后返回的结果 kubeadm join 11.11.11.110:8443 --token yzb7v7.dy40mhlljt1d48i9 --discovery-token-ca-cert-hash sha256:61ec309e6f942305006e6622dcadedcc64420e361231eff23cb535a183c0e77a 复制代码

基础测试

测试容器间的通信和DNS

配置好网络之后，kubeadm会自动部署coredns

如下测试可以在配置kubectl的节点上操作

启动

kubectl run nginx --replicas=2 --image=nginx:alpine --port=80 kubectl expose deployment nginx --type=NodePort --name=example-service-nodeport kubectl expose deployment nginx --name=example-service 复制代码

查看状态

kubectl get deploy kubectl get pods kubectl get svc kubectl describe svc example-service 复制代码

DNS解析

kubectl run curl --image=radial/busyboxplus:curl -i --tty nslookup kubernetes nslookup example-service curl example-service 复制代码

访问测试

# 10.96.59.56 为查看svc时获取到的clusterip curl "10.96.59.56:80" # 32223 为查看svc时获取到的 nodeport http://11.11.11.112:32223/ http://11.11.11.113:32223/ 复制代码

清理删除

kubectl delete svc example-service example-service-nodeport kubectl delete deploy nginx curl 复制代码

高可用测试

关闭任一master节点测试集群是能否正常执行上一步的基础测试，查看相关信息，不能同时关闭两个节点，因为3个节点组成的etcd集群，最多只能有一个当机。

# 查看组件状态 kubectl get pod --all-namespaces -o wide kubectl get pod --all-namespaces -o wide | grep lab1 kubectl get pod --all-namespaces -o wide | grep lab2 kubectl get pod --all-namespaces -o wide | grep lab3 kubectl get nodes -o wide kubectl get deploy kubectl get pods kubectl get svc # 访问测试 CURL_POD=$(kubectl get pods | grep curl | grep Running | cut -d ' ' -f1) kubectl exec -ti $CURL_POD -- sh --tty nslookup kubernetes nslookup example-service curl example-service 复制代码

小技巧

忘记初始master节点时的node节点加入集群命令怎么办

# 简单方法 kubeadm token create --print-join-command # 第二种方法 token=$(kubeadm token generate) kubeadm token create $token --print-join-command --ttl=0

本文转自掘金- 使用kubeadm安装k8s-1.11版本多主高可用