10 minutes to build Kubernetes container cluster platform (kubeadm)

Official Kubernetes deployed three ways

• minikube

Minikube is a tool that can run fast Kubernetes a single point in local, try to develop user Kubernetes or everyday use. It can not be used in production environments.

The official document: https://kubernetes.io/docs/setup/minikube/

• kubeadm

kubeadm can help you quickly deploy a kubernetes cluster. kubeadm designed for new users start trying kubernetes provide a simple method. Currently the Beta version.

The official document: https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm/
https://kubernetes.io/docs/setup/independent/install-kubeadm/

• Binary packages

Downloaded from the official release of the binary package, manually deploy each component, composed Kubernetes clusters. The current production environment, mainly used in this manner.
Download: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.11.md#v1113

1. Installation Requirements

• operating system
  • 16.04+
  • Debian 9
  • 7
  • RHEL 7
  • 25/26 (best-effort)
  • other
• Memory 2GB +, 2-core CPU +
• May communicate between the cluster nodes

• Each node unique host name, MAC address and product_uuid

  • Check MAC address: ifconfig -a use ip link or
  • 检查product_uuid：cat /sys/class/dmi/id/product_uuid
• Prohibit swap partition. In order to make kubelet work

2. Prepare the environment

关闭防火墙：
# systemctl stop firewalld
# systemctl disable firewalld

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

关闭swap：
# swapoff -a  # 临时
# vim /etc/fstab  # 永久

添加主机名与IP对应关系：
# cat /etc/hosts
192.168.0.11 k8s-master
192.168.0.12 k8s-node1
192.168.0.13 k8s-node2

同步时间：
# yum install ntpdate -y
# ntpdate  ntp.api.bz

3. Install Docker

Docker and Kubernetes diagram:

# yum install -y yum-utils device-mapper-persistent-data lvm2 

# yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

# yum install docker-ce-17.03.3.ce -y   #目前kubeadm最大支持docker-ce-17.03，所以要指定该版本安装

# systemctl enable docker && systemctl start docker

If prompted container-selinux dependence problem, install ce-17.03 to match the versions:
# yum localinstall https://download.docker.com/linux/centos/7/x86_64/stable/Packages/docker-ce-selinux-17.03.3.ce-1.el7.noarch.rpm

4. Install kubeadm, kubelet and kubectl

• kubeadm: command to boot cluster
• kubelet: Agent tasks running in the cluster
• kubectl: Management Tools

4.1 Add Ali cloud YUM repositories

# 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
EOF

4.2 Installation kubeadm, kubelet and kubectl

# yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
# systemctl enable kubelet && systemctl start kubelet

Note: When using Docker, kubeadm automatically checks cgroup driver kubelet and /var/lib/kubelet/kubeadm-flags.env at run time to set it in the file. If other CRI used, it must be modified in / etc / default / cgroup-driver in value as kubelet cgroupfs:

# cat /var/lib/kubelet/kubeadm-flags.env
KUBELET_KUBEADM_ARGS=--cgroup-driver=cgroupfs --cni-bin-dir=/opt/cni/bin --cni-conf-dir=/etc/cni/net.d --network-plugin=cni
# systemctl daemon-reload
# systemctl restart kubelet

5. Use kubeadm create a single Master Cluster

5.1 the default download mirror address inaccessible abroad, ready to start the required image

Save the script to run between:

K8S_VERSION=v1.11.2
ETCD_VERSION=3.2.18
DASHBOARD_VERSION=v1.8.3
FLANNEL_VERSION=v0.10.0-amd64
DNS_VERSION=1.1.3
PAUSE_VERSION=3.1
# 基本组件
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver-amd64:$K8S_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager-amd64:$K8S_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler-amd64:$K8S_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy-amd64:$K8S_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/etcd-amd64:$ETCD_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/pause:$PAUSE_VERSION
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:$DNS_VERSION
# 网络组件
docker pull quay.io/coreos/flannel:$FLANNEL_VERSION
# 修改tag
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver-amd64:$K8S_VERSION k8s.gcr.io/kube-apiserver-amd64:$K8S_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager-amd64:$K8S_VERSION k8s.gcr.io/kube-controller-manager-amd64:$K8S_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler-amd64:$K8S_VERSION k8s.gcr.io/kube-scheduler-amd64:$K8S_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy-amd64:$K8S_VERSION k8s.gcr.io/kube-proxy-amd64:$K8S_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/etcd-amd64:$ETCD_VERSION k8s.gcr.io/etcd-amd64:$ETCD_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause:$PAUSE_VERSION k8s.gcr.io/pause:$PAUSE_VERSION
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:$DNS_VERSION k8s.gcr.io/coredns:$DNS_VERSION

5.2 Initialization Master

# kubeadm init --kubernetes-version=1.11.2 --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.0.11

...

Your Kubernetes master has initialized successfully!

To start using your cluster, you need to run (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 addon options listed at:
  http://kubernetes.io/docs/admin/addons/

You can now join any number of machines by running the following on each node
as root:

  kubeadm join --token <token> <master-ip>:<master-port> --discovery-token-ca-cert-hash sha256:<hash>

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

5.3 Pod network installation - Plug

# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.10.0/Documentation/kube-flannel.yml

5.4 Working Party on the node

In Node node performs handover to the root account:

# kubeadm join 192.168.0.11:6443 --token 6hk68y.0rdz1wdjyh85ntkr --discovery-token-ca-cert-hash sha256:d1d3f59ae37fbd632707cbeb9b095d0d0b19af535078091993c4bc4d9d2a7782

格式：kubeadm join --token <token> <master-ip>:<master-port> --discovery-token-ca-cert-hash sha256:<hash>

6. kubernetes Dashboard

First yaml downloaded file, modify the inside mirror and Service NodePort address type.

# wget https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/recommended/kubernetes-dashboard.yaml

Modify Mirror Address:

# registry.cn-hangzhou.aliyuncs.com/google_containers/kubernetes-dashboard-amd64:v1.10.0

Modify Service:

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  type: NodePort
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30001
  selector:
    k8s-app: kubernetes-dashboard

# kubectl apply -f kubernetes-dashboard.yaml

Create an admin role:

apiVersion: v1
kind: ServiceAccount
metadata:
  name: dashboard-admin
  namespace: kube-system
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: dashboard-admin
subjects:
  - kind: ServiceAccount
    name: dashboard-admin
    namespace: kube-system
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io

# kubectl apply -f k8s-admin.yaml

Create an account using the login token of Kubernetes Dashboard:

# kubectl get secret -n kube-system
# kubectl describe secret dashboard-admin-token-bwdjj  -n kube-system
...
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.0hQU5Di_P1OX1DcnW2AYzjDAED66EOrqhF5iupv39wvB8wE-aLRSQyp0twX2M8u1KMZ67n6LxbH17VwEQkMDRVXs7ZlUCyAAD6kHDz3k-f7PAzH5vcuyO4veQ9ooVjk3DKjrP4zXQChHllBB1wmD_oyLjoWxK3Z5MBTlVGzSixVwuQNpFPbuS6Z7iLGwUOgjI0cGZ9Tt6cXzcK81KfAEpDIP_CtFV_Jw4s98EgBex9mZh6vq1dcxr03qfuK--udd_8GWZctu_p_P15hZZLoKEm5GCbs6JGvKL2aao_DEHfLp3XYEnApojI91vU4qAqdkvMZ2qWQNGYv4KNi2yPOOJQ