kubeadm安装

kubeadm安装
安装环境（vm6.5下虚拟机3台，centos 7.4）：
master：10.20.0.191
Node1：10.20.0.192
Node2：10.20.0.193

1.安装虚拟机，配置网络接口；
2.修改主机名
hostnamectl set-hostname k8s-master
3.安装常用工具

yum install wget -y
yum install net-tools -y
yum install vim -y

4.配置yum源环境（是用阿里云镜像）

docker-ce
/etc/yum.repos.d目录下
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
kubernetes
/etc/yum.repos.d目录下
vim kubenetes.repo
[root@k8s-master yum.repos.d]# cat kubenetes.repo 
[kubernetes]
name=Kubernetes Repo
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
gpgcheck=1    #开启gpg校验
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
enabled=1

 yum repolist 检测yum源列表

5.gpg校验配置

下载校验文件
 wget https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
 wget https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
导入校验文件
 rpm --import rpm-package-key.gpg 
 rpm --import yum-key.gpg 

6.关闭firewall，修改内核参数

systemctl disable firewalld
systemctl stop firewalld
vim /etc/sysctl.d/k8s.conf
添加如下内容
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
执行命令生效
modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf
禁用节点上的swap
swapoff -a 
sysctl -p
vim /ets/fstab   #去除该文件中关于swap那行

7.安装docker-ce，kubelet组件

master节点安装
yum install docker-ce kubelet kubeadm kubectl 
node节点安装
yum install docker-ce kubelet kubeadm 

8.启动docker，kubelet

• 编辑kubelet的配置文件/etc/sysconfig/kubelet，设置其忽略Swap启用的状态错误，内容如下: KUBELET_EXTRA_ARGS=“—fail-swap-on=false” ,master以及node节点均需设置；

[root@k8s-master yum.repos.d]# cat /etc/sysconfig/kubelet 
KUBELET_EXTRA_ARGS="--fail-swap-on=false"

• google的镜像仓库k8s.grc.io国内无法访问，如有代理服务器，则编辑docker.service文件，添加代理服务器

vim /usr/lib/systemd/system/docker.service
添加如下内容
Environment="HTTPS_PROXY=https://[proxy-addr]:[proxy-port]/"
保存退出，从新加载配置文件，重启docker
systemctl daemon-reload
systemctl restart docker

• 启动docker，kubelet

systemctl enable docker kubelet 
systemctl start docker

• 无代理服务，可以把k8s的软件包下载到本地安装，通过（docker load）命令加载tar包；
  9.初始化master节点,node节点

master节点需要pull完成的相关镜像
k8s.gcr.io/kube-proxy                            v1.13.3             98db19758ad4        2 weeks ago         80.3MB
k8s.gcr.io/kube-apiserver                        v1.13.3             fe242e556a99        2 weeks ago         181MB
k8s.gcr.io/kube-controller-manager               v1.13.3             0482f6400933        2 weeks ago         146MB
k8s.gcr.io/kube-scheduler                        v1.13.3             3a6f709e97a0        2 weeks ago         79.6MB
k8s.gcr.io/coredns                               1.2.6               f59dcacceff4        3 months ago        40MB
k8s.gcr.io/etcd                                  3.2.24              3cab8e1b9802        5 months ago        220MB
k8s.gcr.io/pause                                 3.1                 da86e6ba6ca1        14 months ago       742kB
quay.io/coreos/flannel                           v0.11.0-amd64       ff281650a721        2 weeks ago         52.6MB

node节点需要pull完成的相关镜像
k8s.gcr.io/kube-proxy               v1.13.3             98db19758ad4        2 weeks ago         80.3MB
k8s.gcr.io/pause                    3.1                 da86e6ba6ca1        14 months ago       742kB
quay.io/coreos/flannel              v0.11.0-amd64       ff281650a721        2 weeks ago         52.6MB

目前默认版本为1.13.3
kubeadm init --help 查看启动参数 默认监听端口6443
kubeadm init --kubernetes-version=v1.13.3 --pod-network-cidr=10.244.0.0/16 service- 
cidr=10.96.0.0/12 --ignore-preflight-errors=Swap 
启动完成后会显示join命令，记得保存
根据提示完成非root用户配置
mkdir ~/.kube 
cp /etc/kubernetes/admin.conf ~/.kube/
chown $(id -u):$(id -g) $HOME/.kube/config

检查启动情况(nodes此时还只有master节点，未安装flannel时候状态不是ready)

[root@k8s-master yum.repos.d]# kubectl get componentstatus
NAME                 STATUS    MESSAGE              ERROR
scheduler            Healthy   ok                   
controller-manager   Healthy   ok                   
etcd-0               Healthy   {"health": "true"}   
[root@k8s-master yum.repos.d]# kubectl get nodes
NAME         STATUS   ROLES    AGE    VERSION
k8s-master   Ready    master   137m   v1.13.3
k8s-node1    Ready    <none>   72m    v1.13.3
k8s-node2    Ready    <none>   59m    v1.13.3

10.安装flannel组件
coredns依赖flannel组件，未安装flannel时候查看coredns的状态为prending

[root@k8s-master yum.repos.d]# kubectl get pods -n kube-system -o wide
NAME                                 READY   STATUS    RESTARTS   AGE    IP            NODE         NOMINATED NODE   READINESS GATES
coredns-86c58d9df4-697md             1/1     Running   0          141m   10.244.0.2    k8s-master   <none>           <none>
coredns-86c58d9df4-7ppx6             1/1     Running   0          141m   10.244.0.3    k8s-master   <none>           <none>
etcd-k8s-master                      1/1     Running   0          140m   10.20.0.191   k8s-master   <none>           <none>
kube-apiserver-k8s-master            1/1     Running   0          140m   10.20.0.191   k8s-master   <none>           <none>
kube-controller-manager-k8s-master   1/1     Running   0          140m   10.20.0.191   k8s-master   <none>           <none>
kube-flannel-ds-amd64-jnr54          1/1     Running   0          108m   10.20.0.191   k8s-master   <none>           <none>
kube-flannel-ds-amd64-n9c74          1/1     Running   0          64m    10.20.0.193   k8s-node2    <none>           <none>
kube-flannel-ds-amd64-x7tj8          1/1     Running   0          77m    10.20.0.192   k8s-node1    <none>           <none>
kube-proxy-8cvq4                     1/1     Running   0          77m    10.20.0.192   k8s-node1    <none>           <none>
kube-proxy-kc6bb                     1/1     Running   0          64m    10.20.0.193   k8s-node2    <none>           <none>
kube-proxy-rcfrt                     1/1     Running   0          141m   10.20.0.191   k8s-master   <none>           <none>
kube-scheduler-k8s-master            1/1     Running   0          141m   10.20.0.191   k8s-master   <none>           <none>

安装flannel

master节点
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
正常会自动pull flannel镜像，如网络不稳定，可以手动pull
docker pull quay.io/coreos/flannel:v0.11.0-amd64
node节点在加入k8s之后会自动pull flannel镜像，无需额外配置；

11.node节点加入k8s

 kubeadm join 10.20.0.191:6443 --token qpibgq.aj47u2bq7l7w898x --discovery-token-ca-cert-hash sha256:868e795381864a9234e2a29f96cd6095831e8775a80a1f2c81319569cb876ff4  --ignore-preflight-errors=Swap

查看状态

[root@k8s-master yum.repos.d]# kubectl get nodes
NAME         STATUS   ROLES    AGE    VERSION
k8s-master   Ready    master   144m   v1.13.3
k8s-node1    Ready    <none>   79m    v1.13.3
k8s-node2    Ready    <none>   66m    v1.13.3