基于kubeadm部署高可用Kubernetes集群

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k8s logo

目录

  1. 部署架构
    1. 概要部署架构
    2. 详细部署架构
    3. 主机节点清单
  2. 安装前准备
    1. 版本信息
    2. 所需docker镜像
    3. 系统设置
  3. kubernetes安装
    1. kubernetes相关服务安装
    2. docker镜像导入
  4. 第一台master初始化
    1. 独立etcd集群部署
    2. kubeadm初始化
    3. flannel网络组件安装
  5. master集群高可用设置
    1. 复制配置
    2. 修改配置
    3. 验证高可用安装
    4. keepalived安装配置
    5. nginx负载均衡配置
    6. kube-proxy配置
    7. 验证master集群高可用
  6. node节点加入高可用集群设置
    1. kubeadm加入高可用集群
    2. 部署应用验证集群

部署架构

概要部署架构

ha logo

  • kubernetes高可用的核心架构是master的高可用，kubectl、客户端以及nodes访问load balancer实现高可用。

返回目录

详细部署架构

k8s ha

  • kubernetes组件说明

kube-apiserver：集群核心，集群API接口、集群各个组件通信的中枢；集群安全控制；

etcd：集群的数据中心，用于存放集群的配置以及状态信息，非常重要，如果数据丢失那么集群将无法恢复；因此高可用集群部署首先就是etcd是高可用集群；

kube-scheduler：集群Pod的调度中心；默认kubeadm安装情况下–leader-elect参数已经设置为true，保证master集群中只有一个kube-scheduler处于活跃状态；

kube-controller-manager：集群状态管理器，当集群状态与期望不同时，kcm会努力让集群恢复期望状态，比如：当一个pod死掉，kcm会努力新建一个pod来恢复对应replicas set期望的状态；默认kubeadm安装情况下–leader-elect参数已经设置为true，保证master集群中只有一个kube-controller-manager处于活跃状态；

kubelet: kubernetes node agent，负责与node上的docker engine打交道；

kube-proxy: 每个node上一个，负责service vip到endpoint pod的流量转发，当前主要通过设置iptables规则实现。

  • 负载均衡

keepalived集群设置一个虚拟ip地址，虚拟ip地址指向k8s-master1、k8s-master2、k8s-master3。

nginx用于k8s-master1、k8s-master2、k8s-master3的apiserver的负载均衡。外部kubectl以及nodes访问apiserver的时候就可以用过keepalived的虚拟ip(192.168.60.80)以及nginx端口(8443)访问master集群的apiserver。

返回目录

主机节点清单

主机名 IP地址 说明 组件
k8s-master1 192.168.60.71 master节点1 keepalived、nginx、etcd、kubelet、kube-apiserver、kube-scheduler、kube-proxy、kube-dashboard、heapster
k8s-master2 192.168.60.72 master节点2 keepalived、nginx、etcd、kubelet、kube-apiserver、kube-scheduler、kube-proxy、kube-dashboard、heapster
k8s-master3 192.168.60.73 master节点3 keepalived、nginx、etcd、kubelet、kube-apiserver、kube-scheduler、kube-proxy、kube-dashboard、heapster
无 192.168.60.80 keepalived虚拟IP 无
k8s-node1 ~ 8 192.168.60.81 ~ 88 8个node节点 kubelet、kube-proxy

返回目录

安装前准备

版本信息

  • Linux版本：CentOS 7.3.1611
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cat /etc/redhat-release 
CentOS Linux release 7.3.1611 (Core)
  • docker版本：1.12.6
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$ docker version
Client:
 Version:      1.12.6
 API version:  1.24
 Go version:   go1.6.4
 Git commit:   78d1802
 Built:        Tue Jan 10 20:20:01 2017
 OS/Arch:      linux/amd64

Server:
 Version:      1.12.6
 API version:  1.24
 Go version:   go1.6.4
 Git commit:   78d1802
 Built:        Tue Jan 10 20:20:01 2017
 OS/Arch:      linux/amd64
  • kubeadm版本：v1.7.0
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$ kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"7", GitVersion:"v1.7.0", GitCommit:"d3ada0119e776222f11ec7945e6d860061339aad", GitTreeState:"clean", BuildDate:"2017-06-29T22:55:19Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}
  • kubelet版本：v1.7.0
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$ kubelet --version
Kubernetes v1.7.0

返回目录

所需docker镜像

  • 国内可以使用daocloud加速器下载相关镜像，然后通过docker save、docker load把本地下载的镜像放到kubernetes集群的所在机器上，daocloud加速器链接如下：

https://www.daocloud.io/mirror#accelerator-doc

  • 在本机MacOSX上pull相关docker镜像
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$ docker pull gcr.io/google_containers/kube-proxy-amd64:v1.7.0
$ docker pull gcr.io/google_containers/kube-apiserver-amd64:v1.7.0
$ docker pull gcr.io/google_containers/kube-controller-manager-amd64:v1.7.0
$ docker pull gcr.io/google_containers/kube-scheduler-amd64:v1.7.0
$ docker pull gcr.io/google_containers/k8s-dns-sidecar-amd64:1.14.4
$ docker pull gcr.io/google_containers/k8s-dns-kube-dns-amd64:1.14.4
$ docker pull gcr.io/google_containers/k8s-dns-dnsmasq-nanny-amd64:1.14.4
$ docker pull nginx:latest
$ docker pull gcr.io/google_containers/kubernetes-dashboard-amd64:v1.6.1
$ docker pull quay.io/coreos/flannel:v0.7.1-amd64
$ docker pull gcr.io/google_containers/heapster-amd64:v1.3.0
$ docker pull gcr.io/google_containers/etcd-amd64:3.0.17
$ docker pull gcr.io/google_containers/heapster-grafana-amd64:v4.0.2
$ docker pull gcr.io/google_containers/heapster-influxdb-amd64:v1.1.1
$ docker pull gcr.io/google_containers/pause-amd64:3.0
  • 在本机MacOSX上获取代码，并进入代码目录
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$ git clone https://github.com/cookeem/kubeadm-ha
$ cd kubeadm-ha
  • 在本机MacOSX上把相关docker镜像保存成文件
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$ mkdir -p docker-images
$ docker save -o docker-images/kube-proxy-amd64  gcr.io/google_containers/kube-proxy-amd64:v1.7.0
$ docker save -o docker-images/kube-apiserver-amd64  gcr.io/google_containers/kube-apiserver-amd64:v1.7.0
$ docker save -o docker-images/kube-controller-manager-amd64  gcr.io/google_containers/kube-controller-manager-amd64:v1.7.0
$ docker save -o docker-images/kube-scheduler-amd64  gcr.io/google_containers/kube-scheduler-amd64:v1.7.0
$ docker save -o docker-images/k8s-dns-sidecar-amd64  gcr.io/google_containers/k8s-dns-sidecar-amd64:1.14.4
$ docker save -o docker-images/k8s-dns-kube-dns-amd64  gcr.io/google_containers/k8s-dns-kube-dns-amd64:1.14.4
$ docker save -o docker-images/k8s-dns-dnsmasq-nanny-amd64  gcr.io/google_containers/k8s-dns-dnsmasq-nanny-amd64:1.14.4
$ docker save -o docker-images/heapster-grafana-amd64  gcr.io/google_containers/heapster-grafana-amd64:v4.2.0
$ docker save -o docker-images/nginx  nginx:latest
$ docker save -o docker-images/kubernetes-dashboard-amd64  gcr.io/google_containers/kubernetes-dashboard-amd64:v1.6.1
$ docker save -o docker-images/flannel  quay.io/coreos/flannel:v0.7.1-amd64
$ docker save -o docker-images/heapster-amd64  gcr.io/google_containers/heapster-amd64:v1.3.0
$ docker save -o docker-images/etcd-amd64  gcr.io/google_containers/etcd-amd64:3.0.17
$ docker save -o docker-images/heapster-grafana-amd64  gcr.io/google_containers/heapster-grafana-amd64:v4.0.2
$ docker save -o docker-images/heapster-influxdb-amd64  gcr.io/google_containers/heapster-influxdb-amd64:v1.1.1
$ docker save -o docker-images/pause-amd64  gcr.io/google_containers/pause-amd64:3.0
  • 在本机MacOSX上把代码以及docker镜像复制到所有节点上
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$ scp -r * root@k8s-master1:/root/kubeadm-ha
$ scp -r * root@k8s-master2:/root/kubeadm-ha
$ scp -r * root@k8s-master3:/root/kubeadm-ha
$ scp -r * root@k8s-node1:/root/kubeadm-ha
$ scp -r * root@k8s-node2:/root/kubeadm-ha
$ scp -r * root@k8s-node3:/root/kubeadm-ha
$ scp -r * root@k8s-node4:/root/kubeadm-ha
$ scp -r * root@k8s-node5:/root/kubeadm-ha
$ scp -r * root@k8s-node6:/root/kubeadm-ha
$ scp -r * root@k8s-node7:/root/kubeadm-ha
$ scp -r * root@k8s-node8:/root/kubeadm-ha

返回目录

系统设置

  • 以下在kubernetes所有节点上都是使用root用户进行操作

  • 在kubernetes所有节点上增加kubernetes仓库 

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$ 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
  • 在kubernetes所有节点上进行系统更新
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$ yum update -y
  • 在kubernetes所有节点上关闭防火墙
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$ systemctl disable firewalld && systemctl stop firewalld && systemctl status firewalld
  • 在kubernetes所有节点上设置SELINUX为permissive模式
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$ vi /etc/selinux/config
SELINUX=permissive
  • 在kubernetes所有节点上设置iptables参数，否则kubeadm init会提示错误
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$ vi /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
  • 在kubernetes所有节点上重启主机
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$ reboot

返回目录

kubernetes安装

kubernetes相关服务安装

  • 在kubernetes所有节点上验证SELINUX模式，必须保证SELINUX为permissive模式，否则kubernetes启动会出现各种异常
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$ getenforce
Permissive
  • 在kubernetes所有节点上安装并启动kubernetes 
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$ yum search docker --showduplicates
$ yum install docker-1.12.6-16.el7.centos.x86_64

$ yum search kubelet --showduplicates
$ yum install kubelet-1.7.0-0.x86_64

$ yum search kubeadm --showduplicates
$ yum install kubeadm-1.7.0-0.x86_64

$ yum search kubernetes-cni --showduplicates
$ yum install kubernetes-cni-0.5.1-0.x86_64

$ systemctl enable docker && systemctl start docker
$ systemctl enable kubelet && systemctl start kubelet

返回目录

docker镜像导入

  • 在kubernetes所有节点上导入docker镜像 
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$ docker load -i /root/kubeadm-ha/docker-images/etcd-amd64
$ docker load -i /root/kubeadm-ha/docker-images/flannel
$ docker load -i /root/kubeadm-ha/docker-images/heapster-amd64
$ docker load -i /root/kubeadm-ha/docker-images/heapster-grafana-amd64
$ docker load -i /root/kubeadm-ha/docker-images/heapster-influxdb-amd64
$ docker load -i /root/kubeadm-ha/docker-images/k8s-dns-dnsmasq-nanny-amd64
$ docker load -i /root/kubeadm-ha/docker-images/k8s-dns-kube-dns-amd64
$ docker load -i /root/kubeadm-ha/docker-images/k8s-dns-sidecar-amd64
$ docker load -i /root/kubeadm-ha/docker-images/kube-apiserver-amd64
$ docker load -i /root/kubeadm-ha/docker-images/kube-controller-manager-amd64
$ docker load -i /root/kubeadm-ha/docker-images/kube-proxy-amd64
$ docker load -i /root/kubeadm-ha/docker-images/kubernetes-dashboard-amd64
$ docker load -i /root/kubeadm-ha/docker-images/kube-scheduler-amd64
$ docker load -i /root/kubeadm-ha/docker-images/pause-amd64
$ docker load -i /root/kubeadm-ha/docker-images/nginx

$ docker images
REPOSITORY                                               TAG                 IMAGE ID            CREATED             SIZE
gcr.io/google_containers/kube-proxy-amd64                v1.7.0              d2d44013d0f8        4 days ago          114.7 MB
gcr.io/google_containers/kube-apiserver-amd64            v1.7.0              f0d4b746fb2b        4 days ago          185.2 MB
gcr.io/google_containers/kube-controller-manager-amd64   v1.7.0              36bf73ed0632        4 days ago          137 MB
gcr.io/google_containers/kube-scheduler-amd64            v1.7.0              5c9a7f60a95c        4 days ago          77.16 MB
gcr.io/google_containers/k8s-dns-sidecar-amd64           1.14.4              38bac66034a6        7 days ago          41.81 MB
gcr.io/google_containers/k8s-dns-kube-dns-amd64          1.14.4              a8e00546bcf3        7 days ago          49.38 MB
gcr.io/google_containers/k8s-dns-dnsmasq-nanny-amd64     1.14.4              f7f45b9cb733        7 days ago          41.41 MB
nginx                                                    latest              958a7ae9e569        4 weeks ago         109.4 MB
gcr.io/google_containers/kubernetes-dashboard-amd64      v1.6.1              71dfe833ce74        6 weeks ago         134.4 MB
quay.io/coreos/flannel                                   v0.7.1-amd64        cd4ae0be5e1b        10 weeks ago        77.76 MB
gcr.io/google_containers/heapster-amd64                  v1.3.0              f9d33bedfed3        3 months ago        68.11 MB
gcr.io/google_containers/etcd-amd64                      3.0.17              243830dae7dd        4 months ago        168.9 MB
gcr.io/google_containers/heapster-grafana-amd64          v4.0.2              a1956d2a1a16        5 months ago        131.5 MB
gcr.io/google_containers/heapster-influxdb-amd64         v1.1.1              d3fccbedd180        5 months ago        11.59 MB
gcr.io/google_containers/pause-amd64                     3.0                 99e59f495ffa        14 months ago       746.9 kB

返回目录

第一台master初始化

独立etcd集群部署

  • 在k8s-master1节点上以docker方式启动etcd集群
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$ docker stop etcd && docker rm etcd
$ rm -rf /var/lib/etcd-cluster
$ mkdir -p /var/lib/etcd-cluster
$ docker run -d \
--restart always \
-v /etc/ssl/certs:/etc/ssl/certs \
-v /var/lib/etcd-cluster:/var/lib/etcd \
-p 4001:4001 \
-p 2380:2380 \
-p 2379:2379 \
--name etcd \
gcr.io/google_containers/etcd-amd64:3.0.17 \
etcd --name=etcd0 \
--advertise-client-urls=http://192.168.60.71:2379,http://192.168.60.71:4001 \
--listen-client-urls=http://0.0.0.0:2379,http://0.0.0.0:4001 \
--initial-advertise-peer-urls=http://192.168.60.71:2380 \
--listen-peer-urls=http://0.0.0.0:2380 \
--initial-cluster-token=9477af68bbee1b9ae037d6fd9e7efefd \
--initial-cluster=etcd0=http://192.168.60.71:2380,etcd1=http://192.168.60.72:2380,etcd2=http://192.168.60.73:2380 \
--initial-cluster-state=new \
--auto-tls \
--peer-auto-tls \
--data-dir=/var/lib/etcd
  • 在k8s-master2节点上以docker方式启动etcd集群
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$ docker stop etcd && docker rm etcd
$ rm -rf /var/lib/etcd-cluster
$ mkdir -p /var/lib/etcd-cluster
$ docker run -d \
--restart always \
-v /etc/ssl/certs:/etc/ssl/certs \
-v /var/lib/etcd-cluster:/var/lib/etcd \
-p 4001:4001 \
-p 2380:2380 \
-p 2379:2379 \
--name etcd \
gcr.io/google_containers/etcd-amd64:3.0.17 \
etcd --name=etcd1 \
--advertise-client-urls=http://192.168.60.72:2379,http://192.168.60.72:4001 \
--listen-client-urls=http://0.0.0.0:2379,http://0.0.0.0:4001 \
--initial-advertise-peer-urls=http://192.168.60.72:2380 \
--listen-peer-urls=http://0.0.0.0:2380 \
--initial-cluster-token=9477af68bbee1b9ae037d6fd9e7efefd \
--initial-cluster=etcd0=http://192.168.60.71:2380,etcd1=http://192.168.60.72:2380,etcd2=http://192.168.60.73:2380 \
--initial-cluster-state=new \
--auto-tls \
--peer-auto-tls \
--data-dir=/var/lib/etcd
  • 在k8s-master3节点上以docker方式启动etcd集群
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$ docker stop etcd && docker rm etcd
$ rm -rf /var/lib/etcd-cluster
$ mkdir -p /var/lib/etcd-cluster
$ docker run -d \
--restart always \
-v /etc/ssl/certs:/etc/ssl/certs \
-v /var/lib/etcd-cluster:/var/lib/etcd \
-p 4001:4001 \
-p 2380:2380 \
-p 2379:2379 \
--name etcd \
gcr.io/google_containers/etcd-amd64:3.0.17 \
etcd --name=etcd2 \
--advertise-client-urls=http://192.168.60.73:2379,http://192.168.60.73:4001 \
--listen-client-urls=http://0.0.0.0:2379,http://0.0.0.0:4001 \
--initial-advertise-peer-urls=http://192.168.60.73:2380 \
--listen-peer-urls=http://0.0.0.0:2380 \
--initial-cluster-token=9477af68bbee1b9ae037d6fd9e7efefd \
--initial-cluster=etcd0=http://192.168.60.71:2380,etcd1=http://192.168.60.72:2380,etcd2=http://192.168.60.73:2380 \
--initial-cluster-state=new \
--auto-tls \
--peer-auto-tls \
--data-dir=/var/lib/etcd
  • 在k8s-master1、k8s-master2、k8s-master3上检查etcd启动状态
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$ docker exec -ti etcd ash

$ etcdctl member list
1a32c2d3f1abcad0: name=etcd2 peerURLs=http://192.168.60.73:2380 clientURLs=http://192.168.60.73:2379,http://192.168.60.73:4001 isLeader=false
1da4f4e8b839cb79: name=etcd1 peerURLs=http://192.168.60.72:2380 clientURLs=http://192.168.60.72:2379,http://192.168.60.72:4001 isLeader=false
4238bcb92d7f2617: name=etcd0 peerURLs=http://192.168.60.71:2380 clientURLs=http://192.168.60.71:2379,http://192.168.60.71:4001 isLeader=true

$ etcdctl cluster-health
member 1a32c2d3f1abcad0 is healthy: got healthy result from http://192.168.60.73:2379
member 1da4f4e8b839cb79 is healthy: got healthy result from http://192.168.60.72:2379
member 4238bcb92d7f2617 is healthy: got healthy result from http://192.168.60.71:2379
cluster is healthy

$ exit

返回目录

kubeadm初始化

  • 在k8s-master1上修改kubeadm-init-v1.7.x.yaml文件，设置etcd.endpoints的${HOST_IP}为k8s-master1、k8s-master2、k8s-master3的IP地址。设置apiServerCertSANs的${HOST_IP}为k8s-master1、k8s-master2、k8s-master3的IP地址，${HOST_NAME}为k8s-master1、k8s-master2、k8s-master3，${VIRTUAL_IP}为keepalived的虚拟IP地址
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$ vi /root/kubeadm-ha/kubeadm-init-v1.7.x.yaml 
apiVersion: kubeadm.k8s.io/v1alpha1
kind: MasterConfiguration
kubernetesVersion: v1.7.0
networking:
  podSubnet: 10.244.0.0/16
apiServerCertSANs:
- k8s-master1
- k8s-master2
- k8s-master3
- 192.168.60.71
- 192.168.60.72
- 192.168.60.73
- 192.168.60.80
etcd:
  endpoints:
  - http://192.168.60.71:2379
  - http://192.168.60.72:2379
  - http://192.168.60.73:2379
  • 如果使用kubeadm初始化集群，启动过程可能会卡在以下位置，那么可能是因为cgroup-driver参数与docker的不一致引起
  • [apiclient] Created API client, waiting for the control plane to become ready
  • journalctl -t kubelet -S ‘2017-06-08’查看日志，发现如下错误
  • error: failed to run Kubelet: failed to create kubelet: misconfiguration: kubelet cgroup driver: “systemd”
  • 需要修改KUBELET_CGROUP_ARGS=–cgroup-driver=systemd为KUBELET_CGROUP_ARGS=–cgroup-driver=cgroupfs
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$ vi /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
#Environment="KUBELET_CGROUP_ARGS=--cgroup-driver=systemd"
Environment="KUBELET_CGROUP_ARGS=--cgroup-driver=cgroupfs"

$ systemctl daemon-reload && systemctl restart kubelet
  • 在k8s-master1上使用kubeadm初始化kubernetes集群，连接外部etcd集群
1
$ kubeadm init --config=/root/kubeadm-ha/kubeadm-init-v1.7.x.yaml
  • 在k8s-master1上修改kube-apiserver.yaml的admission-control，v1.7.0使用了NodeRestriction等安全检查控制，务必设置成v1.6.x推荐的admission-control配置
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$ vi /etc/kubernetes/manifests/kube-apiserver.yaml
#    - --admission-control=Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeLabel,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,ResourceQuota
    - --admission-control=NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeLabel,DefaultStorageClass,ResourceQuota,DefaultTolerationSeconds
  • 在k8s-master1上重启docker kubelet服务
1
$ systemctl restart docker kubelet
  • 在k8s-master1上设置kubectl的环境变量KUBECONFIG，连接kubelet
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$ vi ~/.bashrc
export KUBECONFIG=/etc/kubernetes/admin.conf

$ source ~/.bashrc

返回目录

flannel网络组件安装

  • 在k8s-master1上安装flannel pod网络组件，必须安装网络组件，否则kube-dns pod会一直处于ContainerCreating
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$ kubectl create -f /root/kubeadm-ha/kube-flannel
clusterrole "flannel" created
clusterrolebinding "flannel" created
serviceaccount "flannel" created
configmap "kube-flannel-cfg" created
daemonset "kube-flannel-ds" created
  • 在k8s-master1上验证kube-dns成功启动，大概等待3分钟，验证所有pods的状态为Running
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$ kubectl get pods --all-namespaces -o wide
NAMESPACE     NAME                                 READY     STATUS    RESTARTS   AGE       IP              NODE
kube-system   kube-apiserver-k8s-master1           1/1       Running   0          3m        192.168.60.71   k8s-master1
kube-system   kube-controller-manager-k8s-master1  1/1       Running   0          3m        192.168.60.71   k8s-master1
kube-system   kube-dns-3913472980-k9mt6            3/3       Running   0          4m        10.244.0.104    k8s-master1
kube-system   kube-flannel-ds-3hhjd                2/2       Running   0          1m        192.168.60.71   k8s-master1
kube-system   kube-proxy-rzq3t                     1/1       Running   0          4m        192.168.60.71   k8s-master1
kube-system   kube-scheduler-k8s-master1           1/1       Running   0          3m        192.168.60.71   k8s-master1

返回目录

master集群高可用设置

复制配置

  • 在k8s-master1上把/etc/kubernetes/复制到k8s-master2、k8s-master3
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2
scp -r /etc/kubernetes/ k8s-master2:/etc/
scp -r /etc/kubernetes/ k8s-master3:/etc/
  • 在k8s-master2、k8s-master3上重启kubelet服务，并检查kubelet服务状态为active (running)
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$ systemctl daemon-reload && systemctl restart kubelet

$ systemctl status kubelet
● kubelet.service - kubelet: The Kubernetes Node Agent
   Loaded: loaded (/etc/systemd/system/kubelet.service; enabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/kubelet.service.d
           └─10-kubeadm.conf
   Active: active (running) since Tue 2017-06-27 16:24:22 CST; 1 day 17h ago
     Docs: http://kubernetes.io/docs/
 Main PID: 2780 (kubelet)
   Memory: 92.9M
   CGroup: /system.slice/kubelet.service
           ├─2780 /usr/bin/kubelet --kubeconfig=/etc/kubernetes/kubelet.conf --require-...
           └─2811 journalctl -k -f
  • 在k8s-master2、k8s-master3上设置kubectl的环境变量KUBECONFIG，连接kubelet
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$ vi ~/.bashrc
export KUBECONFIG=/etc/kubernetes/admin.conf

$ source ~/.bashrc
  • 在k8s-master2、k8s-master3检测节点状态，发现节点已经加进来
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$ kubectl get nodes -o wide
NAME          STATUS    AGE       VERSION   EXTERNAL-IP   OS-IMAGE                KERNEL-VERSION
k8s-master1   Ready     26m       v1.7.0    <none>        CentOS Linux 7 (Core)   3.10.0-514.6.1.el7.x86_64
k8s-master2   Ready     2m        v1.7.0    <none>        CentOS Linux 7 (Core)   3.10.0-514.21.1.el7.x86_64
k8s-master3   Ready     2m        v1.7.0    <none>        CentOS Linux 7 (Core)   3.10.0-514.21.1.el7.x86_64

返回目录

修改配置

  • 在k8s-master2、k8s-master3上修改kube-apiserver.yaml的配置，${HOST_IP}改为本机IP
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$ vi /etc/kubernetes/manifests/kube-apiserver.yaml
    - --advertise-address=${HOST_IP}
  • 在k8s-master2和k8s-master3上的修改kubelet.conf设置，${HOST_IP}改为本机IP
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$ vi /etc/kubernetes/kubelet.conf
server: https://${HOST_IP}:6443
  • 在k8s-master2和k8s-master3上修改admin.conf，${HOST_IP}修改为本机IP地址
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$ vi /etc/kubernetes/admin.conf
    server: https://${HOST_IP}:6443
  • 在k8s-master2和k8s-master3上修改controller-manager.conf，${HOST_IP}修改为本机IP地址
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$ vi /etc/kubernetes/controller-manager.conf
    server: https://${HOST_IP}:6443
  • 在k8s-master2和k8s-master3上修改scheduler.conf，${HOST_IP}修改为本机IP地址
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$ vi /etc/kubernetes/scheduler.conf
    server: https://${HOST_IP}:6443
  • 在k8s-master1、k8s-master2、k8s-master3上重启所有服务
1
$ systemctl daemon-reload && systemctl restart docker kubelet

返回目录

验证高可用安装

  • 在k8s-master1、k8s-master2、k8s-master3任意节点上检测服务启动情况，发现apiserver、controller-manager、kube-scheduler、proxy、flannel已经在k8s-master1、k8s-master2、k8s-master3成功启动
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$ kubectl get pod --all-namespaces -o wide | grep k8s-master2
kube-system   kube-apiserver-k8s-master2              1/1       Running   1          55s       192.168.60.72   k8s-master2
kube-system   kube-controller-manager-k8s-master2     1/1       Running   2          18m       192.168.60.72   k8s-master2
kube-system   kube-flannel-ds-t8gkh                   2/2       Running   4          18m       192.168.60.72   k8s-master2
kube-system   kube-proxy-bpgqw                        1/1       Running   1          18m       192.168.60.72   k8s-master2
kube-system   kube-scheduler-k8s-master2              1/1       Running   2          18m       192.168.60.72   k8s-master2

$ kubectl get pod --all-namespaces -o wide | grep k8s-master3
kube-system   kube-apiserver-k8s-master3              1/1       Running   1          1m        192.168.60.73   k8s-master3
kube-system   kube-controller-manager-k8s-master3     1/1       Running   2          18m       192.168.60.73   k8s-master3
kube-system   kube-flannel-ds-tmqmx                   2/2       Running   4          18m       192.168.60.73   k8s-master3
kube-system   kube-proxy-4stg3                        1/1       Running   1          18m       192.168.60.73   k8s-master3
kube-system   kube-scheduler-k8s-master3              1/1       Running   2          18m       192.168.60.73   k8s-master3
  • 在k8s-master1、k8s-master2、k8s-master3任意节点上通过kubectl logs检查各个controller-manager和scheduler的leader election结果，可以发现只有一个节点有效表示选举正常
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$ kubectl logs -n kube-system kube-controller-manager-k8s-master1
$ kubectl logs -n kube-system kube-controller-manager-k8s-master2
$ kubectl logs -n kube-system kube-controller-manager-k8s-master3

$ kubectl logs -n kube-system kube-scheduler-k8s-master1
$ kubectl logs -n kube-system kube-scheduler-k8s-master2
$ kubectl logs -n kube-system kube-scheduler-k8s-master3
  • 在k8s-master1、k8s-master2、k8s-master3任意节点上查看deployment的情况
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$ kubectl get deploy --all-namespaces
NAMESPACE     NAME                   DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kube-system   heapster               1         1         1            1           41m
kube-system   kube-dns               1         1         1            1           48m
kube-system   kubernetes-dashboard   1         1         1            1           43m
kube-system   monitoring-grafana     1         1         1            1           41m
kube-system   monitoring-influxdb    1         1         1            1           41m
  • 在k8s-master1、k8s-master2、k8s-master3任意节点上把kubernetes-dashboard、kube-dns、 scale up成replicas=3，保证各个master节点上都有运行
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$ kubectl scale --replicas=3 -n kube-system deployment/kube-dns
$ kubectl get pods --all-namespaces -o wide| grep kube-dns

$ kubectl scale --replicas=3 -n kube-system deployment/kubernetes-dashboard
$ kubectl get pods --all-namespaces -o wide| grep kubernetes-dashboard

$ kubectl scale --replicas=3 -n kube-system deployment/heapster
$ kubectl get pods --all-namespaces -o wide| grep heapster

$ kubectl scale --replicas=3 -n kube-system deployment/monitoring-grafana
$ kubectl get pods --all-namespaces -o wide| grep monitoring-grafana

$ kubectl scale --replicas=3 -n kube-system deployment/monitoring-influxdb
$ kubectl get pods --all-namespaces -o wide| grep monitoring-influxdb

返回目录

keepalived安装配置

  • 在k8s-master、k8s-master2、k8s-master3上安装keepalived
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$ yum install -y keepalived

$ systemctl enable keepalived && systemctl restart keepalived
  • 在k8s-master1、k8s-master2、k8s-master3上备份keepalived配置文件
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$ mv /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
  • 在k8s-master1、k8s-master2、k8s-master3上设置apiserver监控脚本，当apiserver检测失败的时候关闭keepalived服务，转移虚拟IP地址
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$ vi /etc/keepalived/check_apiserver.sh
#!/bin/bash
err=0
for k in $( seq 1 10 )
do
    check_code=$(ps -ef|grep kube-apiserver | wc -l)
    if [ "$check_code" = "1" ]; then
        err=$(expr $err + 1)
        sleep 5
        continue
    else
        err=0
        break
    fi
done
if [ "$err" != "0" ]; then
    echo "systemctl stop keepalived"
    /usr/bin/systemctl stop keepalived
    exit 1
else
    exit 0
fi

chmod a+x /etc/keepalived/check_apiserver.sh
  • 在k8s-master1、k8s-master2、k8s-master3上查看接口名字
1
$ ip a | grep 192.168.60
  • 在k8s-master1、k8s-master2、k8s-master3上设置keepalived，参数说明如下：
  • state ${STATE}：为MASTER或者BACKUP，只能有一个MASTER
  • interface ${INTERFACE_NAME}：为本机的需要绑定的接口名字（通过上边的ip a命令查看）
  • mcast_src_ip ${HOST_IP}：为本机的IP地址
  • priority ${PRIORITY}：为优先级，例如102、101、100，优先级越高越容易选择为MASTER，优先级不能一样
  • ${VIRTUAL_IP}：为虚拟的IP地址，这里设置为192.168.60.80
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$ vi /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    router_id LVS_DEVEL
}
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
    interval 2
    weight -5
    fall 3  
    rise 2
}
vrrp_instance VI_1 {
    state ${STATE}
    interface ${INTERFACE_NAME}
    mcast_src_ip ${HOST_IP}
    virtual_router_id 51
    priority ${PRIORITY}
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass 4be37dc3b4c90194d1600c483e10ad1d
    }
    virtual_ipaddress {
        ${VIRTUAL_IP}
    }
    track_script {
       chk_apiserver
    }
}
  • 在k8s-master1、k8s-master2、k8s-master3上重启keepalived服务，检测虚拟IP地址是否生效
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$ systemctl restart keepalived
$ ping 192.168.60.80

返回目录

nginx负载均衡配置

  • 在k8s-master1、k8s-master2、k8s-master3上修改nginx-default.conf设置，${HOST_IP}对应k8s-master1、k8s-master2、k8s-master3的地址。通过nginx把访问apiserver的6443端口负载均衡到8433端口上
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$ vi /root/kubeadm-ha/nginx-default.conf
stream {
    upstream apiserver {
        server ${HOST_IP}:6443 weight=5 max_fails=3 fail_timeout=30s;
        server ${HOST_IP}:6443 weight=5 max_fails=3 fail_timeout=30s;
        server ${HOST_IP}:6443 weight=5 max_fails=3 fail_timeout=30s;
    }

    server {
        listen 8443;
        proxy_connect_timeout 1s;
        proxy_timeout 3s;
        proxy_pass apiserver;
    }
}
  • 在k8s-master1、k8s-master2、k8s-master3上启动nginx容器
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$ docker run -d -p 8443:8443 \
--name nginx-lb \
--restart always \
-v /root/kubeadm-ha/nginx-default.conf:/etc/nginx/nginx.conf \
nginx
  • 在k8s-master1、k8s-master2、k8s-master3上检测keepalived服务的虚拟IP地址指向
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$ curl -L 192.168.60.80:8443 | wc -l
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    14    0    14    0     0  18324      0 --:--:-- --:--:-- --:--:-- 14000
1
  • 业务恢复后务必重启keepalived，否则keepalived会处于关闭状态
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$ systemctl restart keepalived
  • 在k8s-master1、k8s-master2、k8s-master3上查看keeplived日志，有以下输出表示当前虚拟IP地址绑定的主机
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$ systemctl status keepalived -l
VRRP_Instance(VI_1) Sending gratuitous ARPs on ens160 for 192.168.60.80

返回目录

kube-proxy配置

  • 在k8s-master1上设置kube-proxy使用keepalived的虚拟IP地址，避免k8s-master1异常的时候所有节点的kube-proxy连接不上
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$ kubectl get -n kube-system configmap
NAME                                 DATA      AGE
extension-apiserver-authentication   6         4h
kube-flannel-cfg                     2         4h
kube-proxy                           1         4h
  • 在k8s-master1上修改configmap/kube-proxy的server指向keepalived的虚拟IP地址
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$ kubectl edit -n kube-system configmap/kube-proxy
        server: https://192.168.60.80:8443
  • 在k8s-master1上查看configmap/kube-proxy设置情况
1
$ kubectl get -n kube-system configmap/kube-proxy -o yaml
  • 在k8s-master1上删除所有kube-proxy的pod，让proxy重建
1
kubectl get pods --all-namespaces -o wide | grep proxy
  • 在k8s-master1、k8s-master2、k8s-master3上重启docker kubelet keepalived服务
1
$ systemctl restart docker kubelet keepalived

返回目录

验证master集群高可用

  • 在k8s-master1上检查各个节点pod的启动状态，每个上都成功启动heapster、kube-apiserver、kube-controller-manager、kube-dns、kube-flannel、kube-proxy、kube-scheduler、kubernetes-dashboard、monitoring-grafana、monitoring-influxdb。并且所有pod都处于Running状态表示正常
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$ kubectl get pods --all-namespaces -o wide | grep k8s-master1

$ kubectl get pods --all-namespaces -o wide | grep k8s-master2

$ kubectl get pods --all-namespaces -o wide | grep k8s-master3

返回目录

node节点加入高可用集群设置

kubeadm加入高可用集群

  • 在k8s-master1上禁止在所有master节点上发布应用
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$ kubectl patch node k8s-master1 -p '{"spec":{"unschedulable":true}}'

$ kubectl patch node k8s-master2 -p '{"spec":{"unschedulable":true}}'

$ kubectl patch node k8s-master3 -p '{"spec":{"unschedulable":true}}'
  • 在k8s-master1上查看集群的token
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$ kubeadm token list
TOKEN           TTL         EXPIRES   USAGES                   DESCRIPTION
xxxxxx.yyyyyy   <forever>   <never>   authentication,signing   The default bootstrap token generated by 'kubeadm init'
  • 在k8s-node1 ~ k8s-node8上，${TOKEN}为k8s-master1上显示的token，${VIRTUAL_IP}为keepalived的虚拟IP地址192.168.60.80
1
$ kubeadm join --token ${TOKEN} ${VIRTUAL_IP}:8443

返回目录

部署应用验证集群

  • 在k8s-node1 ~ k8s-node8上查看kubelet状态，kubelet状态为active (running)表示kubelet服务正常启动
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$ systemctl status kubelet
● kubelet.service - kubelet: The Kubernetes Node Agent
   Loaded: loaded (/etc/systemd/system/kubelet.service; enabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/kubelet.service.d
           └─10-kubeadm.conf
   Active: active (running) since Tue 2017-06-27 16:23:43 CST; 1 day 18h ago
     Docs: http://kubernetes.io/docs/
 Main PID: 1146 (kubelet)
   Memory: 204.9M
   CGroup: /system.slice/kubelet.service
           ├─ 1146 /usr/bin/kubelet --kubeconfig=/etc/kubernetes/kubelet.conf --require...
           ├─ 2553 journalctl -k -f
           ├─ 4988 /usr/sbin/glusterfs --log-level=ERROR --log-file=/var/lib/kubelet/pl...
           └─14720 /usr/sbin/glusterfs --log-level=ERROR --log-file=/var/lib/kubelet/pl...
  • 在k8s-master1上检查各个节点状态，发现所有k8s-nodes节点成功加入
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$ kubectl get nodes -o wide
NAME          STATUS                     AGE       VERSION
k8s-master1   Ready,SchedulingDisabled   5h        v1.7.0
k8s-master2   Ready,SchedulingDisabled   4h        v1.7.0
k8s-master3   Ready,SchedulingDisabled   4h        v1.7.0
k8s-node1     Ready                      6m        v1.7.0
k8s-node2     Ready                      4m        v1.7.0
k8s-node3     Ready                      4m        v1.7.0
k8s-node4     Ready                      3m        v1.7.0
k8s-node5     Ready                      3m        v1.7.0
k8s-node6     Ready                      3m        v1.7.0
k8s-node7     Ready                      3m        v1.7.0
k8s-node8     Ready                      3m        v1.7.0
  • 在k8s-master1上测试部署nginx服务，nginx服务成功部署到k8s-node5上
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$ kubectl run nginx --image=nginx --port=80
deployment "nginx" created

$ kubectl get pod -o wide -l=run=nginx
NAME                     READY     STATUS    RESTARTS   AGE       IP           NODE
nginx-2662403697-pbmwt   1/1       Running   0          5m        10.244.7.6   k8s-node5
  • 在k8s-master1让nginx服务外部可见
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$ kubectl expose deployment nginx --port=80 --target-port=80 --type=NodePort
service "nginx" exposed

$ kubectl get svc -l=run=nginx
NAME      CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
nginx     10.105.151.69   <nodes>       80:31639/TCP   43s

$ curl k8s-master2:31639
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

至此，kubernetes高可用集群成功部署。

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