使用kubeadm部署k8s测试环境(centos7)

回到未来

零、3个节点基本信息如下:

| ip | hostname | 用途 |
| 172.16.180.251 | k8s-master | master 节点 |
| 172.16.180.252 | k8s-node1 | node 节点1 |
| 172.16.180.253 | k8s-node2 | node 节点2 |

一、系统设置及资源准备

这部分三个节点都需要进行配置和准备,当然node节点部分资源可以不下载,将不需要的部分剔除即可。这里为了方便就统一都一样处理吧

0、配置selinux和firewalld

# Set SELinux in permissive mode
setenforce 0
sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config
# Stop and disable firewalld
systemctl disable firewalld --now

1、系统参数与内核模块

# 修改内核参数
cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system

# 加载内核模块
modprobe br_netfilter
lsmod | grep br_netfilter

2、配置yum源

# base repo
cd /etc/yum.repos.d
mv CentOS-Base.repo CentOS-Base.repo.bak
curl -o CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
sed -i 's/gpgcheck=1/gpgcheck=0/g' /etc/yum.repos.d/CentOS-Base.repo

# docker repo
curl -o docker-ce.repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

# k8s repo
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
        http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

# update cache
yum clean all  
yum makecache  
yum repolist

3、禁用swap

swapoff -a
echo "vm.swappiness = 0">> /etc/sysctl.conf
sysctl -p

如果重启后swap又会被挂上,还需要注释掉/etc/fstab中的一行配置:
图片描述

4、安装docker

安装最新版本:
yum install docker-ce

启动docker:
systemctl enable docker --now

查看服务状态:
systemctl status docker

5、安装kubeadm、kubelet和kubectl

yum install -y kubeadm-1.16.1-0 kubelet-1.16.1-0 kubectl-1.16.1-0 --disableexcludes\=kubernetes

启动kubelet:
systemctl enable --now kubelet

6、阿里云镜像加速器配置

mkdir -p /etc/docker
tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://ih25wpox.mirror.aliyuncs.com"]
}
EOF
systemctl daemon-reload
systemctl restart docker

7、镜像下载

然后我们就可以下载image,下载完记得打个tag:
docker pull mirrorgooglecontainers/kube-apiserver-amd64:v1.16.0
docker tag mirrorgooglecontainers/kube-apiserver-amd64:v1.16.0 k8s.gcr.io/kube-apiserver:v1.16.0
docker pull mirrorgooglecontainers/kube-controller-manager-amd64:v1.16.0
docker tag mirrorgooglecontainers/kube-controller-manager-amd64:v1.16.0 k8s.gcr.io/kube-controller-manager:v1.16.0
docker pull mirrorgooglecontainers/kube-scheduler-amd64:v1.16.0
docker tag mirrorgooglecontainers/kube-scheduler-amd64:v1.16.0 k8s.gcr.io/kube-scheduler:v1.16.0
docker pull mirrorgooglecontainers/kube-proxy-amd64:v1.16.0
docker tag mirrorgooglecontainers/kube-proxy-amd64:v1.16.0 k8s.gcr.io/kube-proxy:v1.16.0
docker pull mirrorgooglecontainers/pause-amd64:3.1
docker tag mirrorgooglecontainers/pause-amd64:3.1 k8s.gcr.io/pause:3.1
docker pull mirrorgooglecontainers/etcd-amd64:3.3.15-0
docker tag mirrorgooglecontainers/etcd-amd64:3.3.15-0 k8s.gcr.io/etcd:3.3.15-0
docker pull coredns/coredns:1.6.2
docker tag coredns/coredns:1.6.2 k8s.gcr.io/coredns:1.6.2

docker pull mirrorgooglecontainers/kubernetes-dashboard-amd64:v1.10.1
docker tag mirrorgooglecontainers/kubernetes-dashboard-amd64:v1.10.1 k8s.gcr.io/kubernetes-dashboard-amd64:v1.10.1

二、安装k8s master

tip:下面的ip地址(172.16.180.251)需要替换成自己机器的IP

kubeadm init --pod-network-cidr=10.224.0.0/16 --kubernetes-version=v1.16.0 --apiserver-advertise-address 172.16.180.251 --service-cidr=10.225.0.0/16

--kubernetes-version: 用于指定k8s版本;
--apiserver-advertise-address:用于指定kube-apiserver监听的ip地址;
--pod-network-cidr:用于指定Pod的网络范围;
--service-cidr:用于指定SVC的网络范围;
如上,跑kubeadm init命令后等几分钟。

如果遇到报错,对着错误信息修正一下。比如没有关闭swap会遇到error,系统cpu不够会遇到error,网络不通等等都会出错,仔细看一下错误信息一般都好解决~

跑完上面的命令后,会看到类似如下的输出:

Your Kubernetes master 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 machines by running the following on each node
as root:

  kubeadm join 172.16.180.251:6443 --token apykm6.1rfitzg6x4bmd0ll \
    --discovery-token-ca-cert-hash sha256:114e913f3d254475c33325e7f18b9f49f3ce97244b782a9c871c70f6a0d7c750

上面输出告诉我们还需要做一些工作:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

安装flannel

kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/bc79dd1505b0c8681ece4de4c0d86c5cd2643275/Documentation/kube-flannel.yml

稍等一会,应该可以看到node状态变成ready:

# kubectl get node

NAME STATUS ROLES AGE VERSION

k8s-master Ready master 23m v1.13.3

如果你的环境迟迟都是NotReady状态,可以kubectl get pod -n kube-system看一下pod状态,一般可以发现问题,比如flannel的镜像下载失败之类的

三、添加node节点

在2个node节点执行同样的kube join命令(具体命令master安装完输出的信息里可以找到):

kubeadm join 172.16.180.251:6443 --token apykm6.1rfitzg6x4bmd0ll \
    --discovery-token-ca-cert-hash sha256:114e913f3d254475c33325e7f18b9f49f3ce97244b782a9c871c70f6a0d7c750

将master节点的/etc/kubernetes/admin.conf复制到node节点的相同位置下,并在node节点执行:

echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile
source ~/.bash_profile

执行完成一会后,可以在master节点上看看各节点情况

[root@k8s-master ~]# kubectl get node
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    master   16h   v1.14.3
k8s-node1    Ready    <none>   16h   v1.14.3
k8s-node2    Ready    <none>   16h   v1.14.3

四、安装DashBoard

kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v1.10.1/src/deploy/recommended/kubernetes-dashboard.yaml

#如果没有翻墙或者访问速度太慢可以把yaml文件保存到本地,然后把里面的镜像地址改为国内镜像即可

设置Dashboard集群外访问

执行命令:

kubectl -n kube-system edit service kubernetes-dashboard

把type: ClusterIP 改为 type: NodePort,并保存.

再执行命令查看暴露端口:

$ kubectl -n kube-system get service kubernetes-dashboard
NAME                   CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes-dashboard   10.100.124.90   <nodes>       443:31707/TCP   21h

这是我们可以通过节点服务器IP:端口(如本例:https://172.16.180.251:31707)的方式访问Dashboard了

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