CENTOS7 manual installation of kubernetes clusters

There are several ways to install the Kubernetes cluster, the KUBEADM approach is described earlier, and the manual installation method is described in this article.

The installation environment has 3 VMS on Azure:

HKUBE01:10.0. 1.4 HKUBE02: 10.0. 1.5 Hbube03: 10.0. 1.6

Where hkube01 is the master node, it will install Docker, ETCD, Kubernetes Master, flannel required components;

HKUBE02 and hkube03 are worker nodes and will install Docker, kubernetes node, flannel required components.

The installation process is as follows:

A master node

1 Installing the Software

Yum Install -y docker etcd Kubernetes-master

2 Configuring Boot Docker

Because the Docker-hub site is abroad, the download will be very slow, the Docker download point to the domestic mirror site:

vim/etc/docker/daemon.json{"registry-mirrors": ["  registry.docker-cn.com"]}systemctl enable Dockersystemctl start Docker

3 Configuring Startup Etcd

Etcd and zookeeper are similar and are tools for storing key/value.

cd/etc/etcdvim etcd.confetcd_listen_client_urls="http://0.0.0.0:2379"  Etcd_name="master"etcd_advertise_client_urls=http://  10.0.1.4:2379systemctl enable etcdsystemctl start Etcd

4 Configuring Kubernetes

In the/etc/kubernetes directory, there are 4 configuration files:

Apiserver and config two configuration files need to be configured. Controller-manager and Scheduler do not need to be configured.

To configure the apiserver, you need to specify the ETCD address, the port of the Api-server, the address that provides the service, and the IP range of cluster:

 vim/etc/kubernetes/apiserverkube_api_port  =  " --port=8080   " kube_api_address  = " --insecure-bind-address=0.0.0.0   " kube_etcd_servers  = " --etcd-servers=http://10.0.1.4:2379   " kube_service_addresses  = " --service-cluster-ip-range=10.0.0.0/16  "  admission_control  =namespacelifecycle,namespaceexists,limitranger,resourcequota " 

This article does not design kubernetes security issues, so in the Api-server configuration of the Admission_control to remove the security-related content Securitycontextdeny,serviceaccount.

To configure config, you need to specify the address and port of Kubernetes master:

vim/etc/kubernetes/configkube_master="--master=http://10.0.1.4:8080"

5 Starting the Service

Systemctl Enable Kube-apiserver Kube-controller-manager kube-schedulersystemctl start kube-apiserver Kube-controller-manager kube-schedulersystemctl status kube-apiserver Kube-controller-manager Kube-scheduler

Two node nodes

1 Installing the Software

Yum Install-y Docker Kubernetes-node

2 Configuring Boot Docker

Same as Master node:

vim/etc/docker/daemon.json{"registry-mirrors": ["  registry.docker-cn.com"]}systemctl enable Dockersystemctl start Docker

3 Configuring Kubelet

There are 3 configuration files under/etc/kubernetes:

Config and kubelet two configuration files need to be configured, proxy is the configuration file of Kube-proxy, it can be left by default.

To configure config, you need to specify the address and port of Kubernetes master:

vim/etc/kubernetes/configkube_master="--master=http://10.0.1.4:8080"

Configure Kubelet to specify its work address, the name of the native registered to master, the address of master, and the port:

vim/etc/kubernetes/kubeletkubelet_address="--address=0.0.0.0"kubelet_ HOSTNAME="--hostname-override=hkube02"kubelet_api_server=" --api-servers=http://10.0.1.4:8080 "

Additionally, the Pod-infrastructure docker image specified by the CentOS Yum Source requires a Redhat certificate, which causes the installation to be unsuccessful. To avoid this problem, we changed the image in Kubelet to a mirror in Docker-hub.

Search First:

Docker Search Pod-infrastructure

Select a change, I chose the last one:

kubelet_pod_infra_container=""

4 Starting the Service

Systemctl Enable Kubelet kube-proxysystemctl start kubelet kube-proxysystemctl status Kubelet kube- Proxy

5 Check

On the master node, view:

Have seen HKUBE02 and HKUBE03 are registered up.

Create a deployment:

Kubectl Run Nginx–image=nginx

Kubectl Scale deployment Nginx--replicas=3

However, the network level pod can only be connected to other pods of this node.

Three networks

This article installs the flannel to enable container interoperability across nodes.

1 installation

Yum Install -y flannel

2 configuration

Configuration of the ETCD:

' {"Network": "192.168.0.0/16"} '

To configure the flannel configuration file:

Vim/etc/sysconfig/flannel

Systemctl Enable Flanneldsystemctl start Flannelsystemctl restart Docker

Turn on forwarding:

Iptables-p FORWARD ACCEPT

At this point you can see that the address of the DOCKER0 is the same as the port address segment of flannel:

3 Verification

To deploy the pod Nginx:

Kubectl run Nginx----replicas=3

Log into the hkube03 and go to the container:

By deploying flannel, you can achieve network interoperability across pods.

Summarize:

On Centos7, the Kubernetes components are installed through Yum to achieve kubernetes cluster deployment.

CENTOS7 manual installation of kubernetes clusters