【k8s】kubeadm快速部署Kubernetes

1.Kubernetes 架构图

2.Kubernetes 环境准备

1⃣️关闭防火墙:

systemctl stop firewalld && systemctl disable firewalld

2⃣️关闭selinux:

sed -i 's/enforcing/disabled/' /etc/selinux/config 
setenforce 0

3⃣️关闭swap:

#临时
swapoff -a  
#永久关闭swap分区
sudo sed -ri 's/.*swap.*/#&/' /etc/fstab

4⃣️添加主机名与IP对应关系(记得设置主机名):

cat /etc/hosts
10.211.55.3 k8s-master 
10.211.55.4 k8s-node1
10.211.55.6 k8s-node2
10.211.55.7 k8s-node3

5⃣️将桥接的IPv4流量传递到iptables的链:

cat > /etc/sysctl.d/k8s.conf << EOF net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 EOF
sysctl --system

3.所有节点安装Docker/kubeadm/kubelet

Kubernetes默认CRI(容器运行时)为Docker，因此先安装Docker。
1⃣️安装Docker：

sudo su
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
yum -y install docker-ce-18.06.1.ce-3.el7
systemctl enable docker && systemctl start docker
docker --version

2⃣️添加阿里云YUM软件源：

[root@k8s-master yum.repos.d]# cat /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

3⃣️安装kubeadm，kubelet和kubectl

yum install -y kubelet kubeadm kubectl
systemctl enable kubelet && systemctl start kubelet

4.部署Kubernetes Master

1⃣️由于默认拉取镜像地址k8s.gcr.io国内无法访问，这里指定阿里云镜像仓库地址。

kubeadm init --apiserver-advertise-address=10.211.55.3 --image-repository registry.aliyuncs.com/google_containers --service-cidr=10.1.0.0/16 --pod-network-cidr=10.244.0.0/16

执行init后：

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/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 10.211.55.3:6443 --token eehcsb.r8tnvj7ov436x63q \
    --discovery-token-ca-cert-hash sha256:583f343b5d55ff96c5a83ccc82444de3c0313adf135d8a980507932aa2f51e1d

如果出错，执行：

 kubeadm reset
#kubeadm详细用法可查看kubeadm --help

2⃣️使用kubectl工具:

[root@k8s-master yum.repos.d]# mkdir -p $HOME/.kube
[root@k8s-master yum.repos.d]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-master yum.repos.d]# sudo chown $(id -u):$(id -g) $HOME/.kube/config
[root@k8s-master yum.repos.d]# kubectl get nodes
NAME         STATUS     ROLES    AGE     VERSION
k8s-master   NotReady   master   8m33s   v1.17.0

另外，提示我们还需要创建网络，并且让其他节点执行kubeadm join...加入集群。

5.创建网络

如果不创建网络，查看pod状态时，可以看到kube-dns组件是阻塞状态，集群时不可用的：

[root@k8s-master yum.repos.d]# kubectl get pod -n kube-system
NAME                                 READY   STATUS    RESTARTS   AGE
coredns-9d85f5447-n9kkd              0/1     Pending   0          25m
coredns-9d85f5447-s9ms2              0/1     Pending   0          25m
etcd-k8s-master                      1/1     Running   0          25m
kube-apiserver-k8s-master            1/1     Running   0          25m
kube-controller-manager-k8s-master   1/1     Running   0          25m
kube-proxy-94wtc                     1/1     Running   0          5m41s
kube-proxy-h8q8h                     1/1     Running   0          5m45s
kube-proxy-kxmxt                     1/1     Running   0          25m
kube-proxy-nxtpq                     1/1     Running   0          5m44s
kube-scheduler-k8s-master            1/1     Running   0          25m

网络创建有问题，未完，明日解决再更新...