搭建K8S高可用集群K8S+Keepalived+HA
#部署不出来来找我
1、部署环境说明
本文通过kubeadm搭建一个高可用的k8s集群，kubeadm可以帮助我们快速的搭建k8s集群，高可用主要体现在对master节点组件及etcd存储的高可用，文中使用到的服务器ip及角色对应如下：
| 主机名称 | ip地址 | 角色 |
|---|---|---|
| - | 192.168.9.80 | 虚拟ip(vip) |
| k8s-master-01 | 192.168.9.81 | master |
| K8s-master-02 | 192.168.9.82 | master |
| k8s-node-01 | 192.168.9.84 | node |
2、集群架构及部署准备工作
2.1、集群架构说明
前面提到高可用主要体现在master相关组件及etcd，master中apiserver是集群的入口，搭建三个master通过keepalived提供一个vip实现高可用，并且添加haproxy来为apiserver提供反向代理的作用，这样来自haproxy的所有请求都将轮询转发到后端的master节点上。如果仅仅使用keepalived，当集群正常工作时，所有流量还是会到具有vip的那台master上，因此加上了haproxy使整个集群的master都能参与进来，集群的健壮性更强。还有值得注意的是这里的etcd也是集群化的，集群化的方式是kubeadm默认实现的，具体原理我也不是很清楚，希望有大佬可以解答对应架构图如下所示：
2.2、修改hosts及hostname
所有节点修改主机名和hosts文件，文件内容如下
192.168.9.80 master.k8s.io k8s-vip
192.168.9.81 master01.k8s.io k8s-master-01
192.168.9.82 master02.k8s.io k8s-master-02
192.168.9.84 node01.k8s.io k8s-node-012.3、其他准备
所有节点操作
-
主机时间同步
时间同步可以通过chrony或者ntp来实现，这里不再赘述 -
关闭防火墙
关闭centos7自带的firewalld防火墙服务 -
关闭selinux
-
禁用swap
kubeadm会检查当前主机是否禁用了swap，如果启动了swap将导致安装不能正常进行，所以需要禁用所有的swap。
# 临时关闭
$ swapoff -a && sysctl -w vm.swappiness=0
# 永久关闭，在文件中添加注释
$ vim /etc/fstab
...
UUID=7bf41652-e6e9-415c-8dd9-e112641b220e /boot xfs defaults 0 0
#/dev/mapper/centos-swap swap swap defaults 0 0
# 或者利用sed命令完事儿
$ sed -ri '/^[^#]*swap/s@^@#@' /etc/fstab- 设置系统其它参数
开启路由转发
$ vim /etc/sysctl.d/k8s.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
$ modprobe br_netfilter
$ sysctl -p /etc/sysctl.d/k8s.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1设置资源配置文件
$ echo "* soft nofile 65536" >> /etc/security/limits.conf
$ echo "* hard nofile 65536" >> /etc/security/limits.conf
$ echo "* soft nproc 65536" >> /etc/security/limits.conf
$ echo "* hard nproc 65536" >> /etc/security/limits.conf
$ echo "* soft memlock unlimited" >> /etc/security/limits.conf
$ echo "* hard memlock unlimited" >> /etc/security/limits.conf- 安装相关包
$ yum install -y conntrack-tools libseccomp libtool-ltdl3、部署keepalived
在三台master操作
3.1、安装
$ yum install -y keepalived3.2、配置
默认的keepalived配置较复杂，这里用更为简明的方式进行配置，另外的两台master配置和上面类似，只需要修改对应的state配置为BACKUP，priority权重值不同即可，配置中的其他字段这里不做说明。
k8s-master-01的配置：
cat > /etc/keepalived/keepalived.conf <<EOF
! Configuration File for keepalived
global_defs {
router_id k8s
}
vrrp_script check_haproxy {
script "killall -0 haproxy"
interval 3
weight -2
fall 10
rise 2
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 250
#以下的配置是当你的上游交换机禁止ARP广播的时候需要添加的配置，如果不添加的话，keepalived会出现脑裂的情况
#unicast_src_ip 10.0.05 #本机ip
#unicast_peer {
# 10.0.0.9 #对端ip
#}
advert_int 1
authentication {
auth_type PASS
auth_pass ceb1b3ec013d66163d6ab
}
virtual_ipaddress {
192.168.9.80
}
track_script {
check_haproxy
}
}
EOFk8s-master-02的配置：
cat > /etc/keepalived/keepalived.conf <<EOF
! Configuration File for keepalived
global_defs {
router_id k8s
}
vrrp_script check_haproxy {
script "killall -0 haproxy"
interval 3
weight -2
fall 10
rise 2
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 200
advert_int 1
authentication {
auth_type PASS
auth_pass ceb1b3ec013d66163d6ab
}
virtual_ipaddress {
192.168.9.80
}
track_script {
check_haproxy
}
}
EOF3.3、启动和检查
在两台master节点都启动服务
# 设置开机启动
$ systemctl enable keepalived.service
# 启动keepalived
$ systemctl start keepalived.service
# 查看启动状态
$ systemctl status keepalived.service启动后查看k8s-master-01的网卡信息
[root@k8s-master-01 ~]# ip a s eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:0c:29:84:45:8a brd ff:ff:ff:ff:ff:ff
inet 192.168.9.81/24 brd 192.168.9.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.9.80/32 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe84:458a/64 scope link
valid_lft forever preferred_lft forever尝试停掉k8s-master-01的keepalived服务，查看vip是否能漂移到其他的master，并且重新启动k8s-master-01的keepalived服务，查看vip是否能正常漂移回来，证明配置没有问题。
4、部署haproxy
在两台master操作
4.1、安装
$ yum install -y haproxy4.2、配置
两台master节点的配置均相同，配置中声明了后端代理的两个master节点服务器，指定了haproxy运行的端口为16443等，因此16443端口为集群的入口，其他的配置不做赘述。
cat > /etc/haproxy/haproxy.cfg << EOF
#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global
# to have these messages end up in /var/log/haproxy.log you will
# need to:
# 1) configure syslog to accept network log events. This is done
# by adding the '-r' option to the SYSLOGD_OPTIONS in
# /etc/sysconfig/syslog
# 2) configure local2 events to go to the /var/log/haproxy.log
# file. A line like the following can be added to
# /etc/sysconfig/syslog
#
# local2.* /var/log/haproxy.log
#
log 127.0.0.1 local2
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 4000
user haproxy
group haproxy
daemon
# turn on stats unix socket
stats socket /var/lib/haproxy/stats
#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
mode http
log global
option httplog
option dontlognull
option http-server-close
option forwardfor except 127.0.0.0/8
option redispatch
retries 3
timeout http-request 10s
timeout queue 1m
timeout connect 10s
timeout client 1m
timeout server 1m
timeout http-keep-alive 10s
timeout check 10s
maxconn 3000
#---------------------------------------------------------------------
# kubernetes apiserver frontend which proxys to the backends
#---------------------------------------------------------------------
frontend kubernetes-apiserver
mode tcp
bind *:16443
option tcplog
default_backend kubernetes-apiserver
#---------------------------------------------------------------------
# round robin balancing between the various backends
#---------------------------------------------------------------------
backend kubernetes-apiserver
mode tcp
balance roundrobin
server k8s-master-01 192.168.9.81:6443 check
server k8s-master-02 192.168.9.82:6443 check
#---------------------------------------------------------------------
# collection haproxy statistics message
#---------------------------------------------------------------------
listen stats
bind *:1080
stats auth admin:awesomePassword
stats refresh 5s
stats realm HAProxy\ Statistics
stats uri /admin?stats
EOF4.3、启动和检查
在两台master节点都启动服务
# 设置开机启动
$ systemctl enable haproxy
# 开启haproxy
$ systemctl start haproxy
# 查看启动状态
$ systemctl status haproxy检查端口
[root@k8s-master-01 ~]# netstat -lntup|grep haproxy
tcp 0 0 0.0.0.0:1080 0.0.0.0:* LISTEN 7067/haproxy
tcp 0 0 0.0.0.0:16443 0.0.0.0:* LISTEN 7067/haproxy
udp 0 0 0.0.0.0:47041 0.0.0.0:* 7066/haproxy5、安装docker
所有节点操作，使用yum安装，参考阿里云镜像站指导
5.1、安装
# step 1: 安装必要的一些系统工具
$ yum install -y yum-utils device-mapper-persistent-data lvm2
# Step 2: 添加软件源信息
$ sudo yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
# Step 3: 查找Docker-CE的版本:
$ yum list docker-ce.x86_64 --showduplicates | sort -r
# Step 4: 安装指定版本的Docker-CE
$ yum makecache fast
$ yum install -y docker-ce-18.09.95.2、配置
修改docker的配置文件，目前k8s推荐使用的docker文件驱动是systemd，按照k8s官方文档可查看如何配置
$ mkdir -p /etc/docker
$ vim /etc/docker/daemon.json
{
"insecure-registries": [
192.168.*.*:5000" #这是我自己的镜像仓库地址
],
"registry-mirrors" : [
"这里配置你自己阿里云的镜像加速地址" #不会的话可以找客服
]
}修改docker的服务配置文件，指定docker的数据目录为外挂的磁盘--graph /data/docker
$ vim /lib/systemd/system/docker.service
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock --graph /data/docker5.3、启动
启动docker服务
$ systemctl daemon-reload
$ systemctl start docker.service
$ systemctl enable docker.service
$ systemctl status docker.service检查docker信息
$ docker version
Client: Docker Engine - Community
Version: 19.03.5
API version: 1.39 (downgraded from 1.40)
Go version: go1.12.12
Git commit: 633a0ea
Built: Wed Nov 13 07:25:41 2019
OS/Arch: linux/amd64
Experimental: false
Server: Docker Engine - Community
Engine:
Version: 18.09.9
API version: 1.39 (minimum version 1.12)
Go version: go1.11.13
Git commit: 039a7df
Built: Wed Sep 4 16:22:32 2019
OS/Arch: linux/amd64
Experimental: false6、安装kubeadm，kubelet和kubectl
所有节点操作
6.1、添加阿里云k8s的yum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
EOF6.2、安装
$ yum install -y kubelet-1.16.3 kubeadm-1.16.3 kubectl-1.16.3
$ systemctl enable kubelet6.3、配置kubectl自动补全
[root@k8s-master-01 ~]# source <(kubectl completion bash)
[root@k8s-master-01 ~]# echo "source <(kubectl completion bash)" >> ~/.bashrc7、安装master
在具有vip的master上操作，这里为k8s-master-01
7.1、创建kubeadm配置文件
[root@k8s-master-01 ~]# mkdir /usr/local/kubernetes/manifests -p
[root@k8s-master-01 ~]# cd /usr/local/kubernetes/manifests/
[root@k8s-master-01 manifests]# vim kubeadm-config.yaml
apiServer:
certSANs:
- 192.168.9.80
- 192.168.9.81
- 192.168.9.82
- 192.168.9.84
- 127.0.0.1
extraArgs:
authorization-mode: Node,RBAC
timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta1
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: "192.168.9.80:16443"
controllerManager: {}
dns:
type: CoreDNS
etcd:
local:
dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.16.3
networking:
dnsDomain: cluster.local
podSubnet: 10.244.0.0/16
serviceSubnet: 10.96.0.0/12
scheduler: {}7.2、初始化master节点
[root@k8s-master-01 manifests]# kubeadm init --config kubeadm-config.yaml
[init] Using Kubernetes version: v1.16.3
[preflight] Running pre-flight checks
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Activating the kubelet service
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8s-master-01 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local master.k8s.io k8s-master-01 k8s-master-02 k8s-master-03 master.k8s.io] and IPs [10.1.0.1 192.168.9.81 192.168.9.80 192.168.9.81 192.168.9.82 192.168.9.83 127.0.0.1]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [k8s-master-01 localhost] and IPs [192.168.9.81 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-master-01 localhost] and IPs [192.168.9.81 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Writing "admin.conf" kubeconfig file
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[apiclient] All control plane components are healthy after 21.505682 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.16" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node k8s-master-01 as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node k8s-master-01 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: jv5z7n.3y1zi95p952y9p65
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[addons] Applied essential addon: CoreDNS
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[addons] Applied essential addon: kube-proxy
Your Kubernetes control-plane has initialized successfully!
To start using your cluster, you need to run the following as a regular user:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
https://kubernetes.io/docs/concepts/cluster-administration/addons/
You can now join any number of control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:
kubeadm join 192.168.9.80:16443 --token jv5z7n.3y1zi95p952y9p65 \
--discovery-token-ca-cert-hash sha256:403bca185c2f3a4791685013499e7ce58f9848e2213e27194b75a2e3293d8812 \
--control-plane
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join 192.168.9.80:16443 --token jv5z7n.3y1zi95p952y9p65 \
--discovery-token-ca-cert-hash sha256:403bca185c2f3a4791685013499e7ce58f9848e2213e27194b75a2e3293d88127.3、按照提示配置环境变量
[root@k8s-master-01 manifests]# mkdir -p $HOME/.kube
[root@k8s-master-01 manifests]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-master-01 manifests]# sudo chown $(id -u):$(id -g) $HOME/.kube/config7.4、查看集群状态
[root@k8s-master-01 manifests]# kubectl get cs
NAME AGE
scheduler <unknown>
controller-manager <unknown>
etcd-0 <unknown>
[root@k8s-master-01 manifests]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-58cc8c89f4-56n7g 0/1 Pending 0 87s
coredns-58cc8c89f4-zclz7 0/1 Pending 0 87s
etcd-k8s-master-01 1/1 Running 0 18s
kube-apiserver-k8s-master-01 1/1 Running 0 21s
kube-controller-manager-k8s-master-01 1/1 Running 0 33s
kube-proxy-ptjjn 1/1 Running 0 87s
kube-scheduler-k8s-master-01 1/1 Running 0 25s执行kubectl get cs显示<unknown>是一个1.16版本已知的bug，后续官方应该会解决处理，有大佬分析了源码并且提交了pr，可点此参考
集群默认也把coredns安装了，这里处于pending状态的原因是因为还没有安装网络组件
8、安装集群网络
master节点操作
8.1、获取yaml
从官方地址获取到flannel的yaml
[root@k8s-master-01 manifests]# mkdir flannel
[root@k8s-master-01 manifests]# cd flannel
[root@k8s-master-01 flannel]# wget -c https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml确保yaml中的pod子网与前面执行kubeadm初始化时相同，yaml中的镜像如果无法获取，可以使用微软中国镜像源代替，例如
quay.io/coreos/flannel:v0.11.0-amd64 # 源地址
quay.azk8s.cn/coreos/flannel:v0.11.0-amd64 # 代替8.2、安装
[root@k8s-master-01 flannel]# kubectl apply -f kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds-amd64 created
daemonset.apps/kube-flannel-ds-arm64 created
daemonset.apps/kube-flannel-ds-arm created
daemonset.apps/kube-flannel-ds-ppc64le created
daemonset.apps/kube-flannel-ds-s390x created8.3、检查
[root@k8s-master-01 flannel]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-58cc8c89f4-56n7g 1/1 Running 0 20m
coredns-58cc8c89f4-zclz7 1/1 Running 0 20m
etcd-k8s-master-01 1/1 Running 0 19m
kube-apiserver-k8s-master-01 1/1 Running 0 19m
kube-controller-manager-k8s-master-01 1/1 Running 0 19m
kube-flannel-ds-amd64-8d8bc 1/1 Running 0 51s
kube-proxy-ptjjn 1/1 Running 0 20m
kube-scheduler-k8s-master-01 1/1 Running 0 19m9、其他节点加入集群
9.1、master加入集群
9.1.1、复制密钥及相关文件
在第一次执行init的机器，此处为k8s-master-01上操作
复制文件到k8s-master-02
[root@k8s-master-01 ~]# ssh root@192.168.9.82 mkdir -p /etc/kubernetes/pki/etcd
[root@k8s-master-01 ~]# scp /etc/kubernetes/admin.conf root@192.168.9.82:/etc/kubernetes
admin.conf 100% 5454 465.7KB/s 00:00
[root@k8s-master-01 ~]# scp /etc/kubernetes/pki/{ca.*,sa.*,front-proxy-ca.*} root@192.168.9.82:/etc/kubernetes/pki
ca.crt 100% 1025 89.2KB/s 00:00
ca.key 100% 1675 212.1KB/s 00:00
sa.key 100% 1679 210.1KB/s 00:00
sa.pub 100% 451 56.5KB/s 00:00
front-proxy-ca.crt 100% 1038 131.9KB/s 00:00
front-proxy-ca.key 100% 1679 208.3KB/s 00:00
[root@k8s-master-01 ~]# scp /etc/kubernetes/pki/etcd/ca.* root@192.168.9.82:/etc/kubernetes/pki/etcd
ca.crt 100% 1017 138.8KB/s 00:00
ca.key9.1.2、master加入集群
分别在其他一台master上操作，执行在k8s-master-01上init后输出的join命令，如果找不到了，可以在master01上执行以下命令输出
[root@k8s-master-01 ~]# kubeadm token create --print-join-command
kubeadm join master.k8s.io:16443 --token ckf7bs.30576l0okocepg8b --discovery-token-ca-cert-hash sha256:19afac8b11182f61073e254fb57b9f19ab4d798b70501036fc69ebef46094aba在k8s-master-02上执行join命令，需要带上参数--control-plane表示把master控制节点加入集群
[root@k8s-master-02 ~]# kubeadm join master.k8s.io:16443 --token ckf7bs.30576l0okocepg8b --discovery-token-ca-cert-hash sha256:19afac8b11182f61073e254fb57b9f19ab4d798b70501036fc69ebef46094aba --control-plane
[preflight] Running pre-flight checks
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[preflight] Running pre-flight checks before initializing the new control plane instance
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8s-master-02 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local master.k8s.io k8s-master-01 k8s-master-02 k8s-master-03 master.k8s.io] and IPs [10.1.0.1 192.168.9.82 192.168.9.80 192.168.9.81 192.168.9.82 192.168.9.83 127.0.0.1]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-master-02 localhost] and IPs [192.168.9.82 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [k8s-master-02 localhost] and IPs [192.168.9.82 127.0.0.1 ::1]
[certs] Generating "front-proxy-client" certificate and key
[certs] Valid certificates and keys now exist in "/etc/kubernetes/pki"
[certs] Using the existing "sa" key
[kubeconfig] Generating kubeconfig files
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address
[kubeconfig] Using existing kubeconfig file: "/etc/kubernetes/admin.conf"
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[check-etcd] Checking that the etcd cluster is healthy
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.16" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Activating the kubelet service
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
[etcd] Announced new etcd member joining to the existing etcd cluster
[etcd] Creating static Pod manifest for "etcd"
[etcd] Waiting for the new etcd member to join the cluster. This can take up to 40s
{"level":"warn","ts":"2019-11-27T13:33:59.913+0800","caller":"clientv3/retry_interceptor.go:61","msg":"retrying of unary invoker failed","target":"passthrough:///https://192.168.9.82:2379","attempt":0,"error":"rpc error: code = DeadlineExceeded desc = context deadline exceeded"}
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[mark-control-plane] Marking the node k8s-master-02 as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node k8s-master-02 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
This node has joined the cluster and a new control plane instance was created:
* Certificate signing request was sent to apiserver and approval was received.
* The Kubelet was informed of the new secure connection details.
* Control plane (master) label and taint were applied to the new node.
* The Kubernetes control plane instances scaled up.
* A new etcd member was added to the local/stacked etcd cluster.
To start administering your cluster from this node, you need to run the following as a regular user:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
Run 'kubectl get nodes' to see this node join the cluster.
[root@k8s-master-02 ~]# mkdir -p $HOME/.kube
[root@k8s-master-02 ~]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-master-02 ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config9.1.3、检查
在其中一台master上执行命令检查集群及pod状态
[root@k8s-master-01 ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master-01 Ready master 36m v1.16.3
k8s-master-02 Ready master 3m20s v1.16.3
[root@k8s-master-01 ~]# kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-58cc8c89f4-56n7g 1/1 Running 0 36m
kube-system coredns-58cc8c89f4-zclz7 1/1 Running 0 36m
kube-system etcd-k8s-master-01 1/1 Running 0 35m
kube-system etcd-k8s-master-02 1/1 Running 0 3m55s
kube-system kube-apiserver-k8s-master-01 1/1 Running 0 35m
kube-system kube-apiserver-k8s-master-02 1/1 Running 0 3m55s
kube-system kube-controller-manager-k8s-master-01 1/1 Running 1 35m
kube-system kube-controller-manager-k8s-master-02 1/1 Running 0 3m55s
kube-system kube-flannel-ds-amd64-7hnhl 1/1 Running 1 3m56s
kube-system kube-flannel-ds-amd64-8d8bc 1/1 Running 0 17m
kube-system kube-flannel-ds-amd64-fp2rb 1/1 Running 0 57s
kube-system kube-proxy-gzswt 1/1 Running 0 3m56s
kube-system kube-proxy-hdrq7 1/1 Running 0 57s
kube-system kube-proxy-ptjjn 1/1 Running 0 36m
kube-system kube-scheduler-k8s-master-01 1/1 Running 1 35m
kube-system kube-scheduler-k8s-master-02 1/1 Running 0 3m55s9.2、node加入集群
9.2.1、node加入集群
分别在其他node节点上操作，执行join命令
在k8s-node-01上操作
[root@k8s-node-02 ~]# kubeadm join master.k8s.io:16443 --token ckf7bs.30576l0okocepg8b --discovery-token-ca-cert-hash sha256:19afac8b11182f61073e254fb57b9f19ab4d798b70501036fc69ebef46094aba
[preflight] Running pre-flight checks
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.16" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Activating the kubelet service
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the control-plane to see this node join the cluster.9.2.2、检查
[root@k8s-master-01 ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-master-01 Ready master 42m v1.16.3
k8s-master-02 Ready master 9m3s v1.16.3
k8s-node-01 Ready <none> 31s v1.16.3
[root@k8s-master-01 ~]# kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-58cc8c89f4-56n7g 1/1 Running 0 41m
kube-system coredns-58cc8c89f4-zclz7 1/1 Running 0 41m
kube-system etcd-k8s-master-01 1/1 Running 0 40m
kube-system etcd-k8s-master-02 1/1 Running 0 9m4s
kube-system kube-apiserver-k8s-master-01 1/1 Running 0 40m
kube-system kube-apiserver-k8s-master-02 1/1 Running 0 9m4s
kube-system kube-controller-manager-k8s-master-01 1/1 Running 1 40m
kube-system kube-controller-manager-k8s-master-02 1/1 Running 0 9m4s
kube-system kube-flannel-ds-amd64-7hnhl 1/1 Running 1 9m5s
kube-system kube-flannel-ds-amd64-8d8bc 1/1 Running 0 22m
kube-system kube-flannel-ds-amd64-bwwlx 1/1 Running 0 33s
kube-system kube-flannel-ds-amd64-fp2rb 1/1 Running 0 6m6s
kube-system kube-proxy-485dl 1/1 Running 0 30s
kube-system kube-proxy-8p688 1/1 Running 0 40s
kube-system kube-proxy-fdq7c 1/1 Running 0 33s
kube-system kube-scheduler-k8s-master-01 1/1 Running 1 40m
kube-system kube-scheduler-k8s-master-02 1/1 Running 0 9m4s9.3、集群后续扩容
默认情况下加入集群的token是24小时过期，24小时后如果是想要新的node加入到集群，需要重新生成一个token，命令如下
# 显示获取token列表
$ kubeadm token list
# 生成新的token
$ kubeadm token create除token外，join命令还需要一个sha256的值，通过以下方法计算
openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'用上面输出的token和sha256的值或者是利用kubeadm token create --print-join-command拼接join命令即可
10、集群缩容
master节点
kubectl drain <node name> --delete-local-data --force --ignore-daemonsets
kubectl delete node <node name>node节点
kubeadm reset本文参考博客：https://www.cnblogs.com/ssgeek/p/11942062.html
