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This article introduces how to build a kubernetes cluster environment in CentOS7. The content is very detailed. Interested friends can use it for reference. I hope it will be helpful to you.

I. preparation of server environment

192.168.247.128: k8s-master 、 etcd 、 registry

192.168.247.129: k8s-nodeA

192.168.247.130: k8s-nodeB

Note: install the lsb_release command: yum install redhat-lsb-y

The three machines have the same configuration.

Install the same version of docker:

[root@localhost] # docker-v

Docker version 1.12.6, build 85d7426/1.12.6

Modify the hostname on the three machines:

Run on master:

[root@localhost] # hostnamectl-- static set-hostname k8s-master

Run on nodeA:

[root@localhost] # hostnamectl-- static set-hostname k8s-nodeA

Run on nodeB:

[root@localhost] # hostnamectl-- static set-hostname k8s-nodeB

Configure hosts on each of the three machines and execute the following command to modify the hosts file:

Echo '192.168.247.128 k8s-master192.168.247.128 etcd192.168.247.128 registry192.168.247.129 k8s-nodeA192.168.247.130 k8sMurnodeB' > / etc/hosts

Turn off the firewall on the three machines and execute on each of the three machines:

[root@localhost ~] # systemctl stop firewalld

Note: firewall related commands:

View firewall status: systemctl status firewalld

Turn off the firewall: systemctl stop firewalld

Turn on the firewall: systemctl start firewalld

Before closing:

After closing:

Second, install etcd

K8s depends on etcd. You need to install etcd first, and install etcd in yum mode:

Run on k8s-master:

Yum install etcd-y

Edit the configuration file after the installation is completed. The default configuration file for etcd installed by yum is / etc/etcd/etcd.conf.

Modify the following three parameter values:

Start etcd by executing the following command, and verify that the status is correct:

[root@localhost ~] # systemctl start etcd

[root@localhost ~] # etcdctl set developer xiejunbo

Xiejunbo

[root@localhost ~] # etcdctl get developer

Xiejunbo

[root@localhost] # etcdctl-C http://etcd:4001 cluster-health

Member 8e9e05c52164694d is healthy: got healthy result from http://etcd:2379

Cluster is healthy

[root@localhost] # etcdctl-C http://etcd:2379 cluster-health

Member 8e9e05c52164694d is healthy: got healthy result from http://etcd:2379

Cluster is healthy

It shows that the ectd is healthy and can be used normally.

3. Deploy k8s-master

Install docker:

Yum install docker

Modify the docker configuration file: vi / etc/sysconfig/docker

Set docker to boot automatically, and then enable the docker service:

[root@localhost ~] # chkconfig docker on

[root@localhost ~] # service docker start

Install kubernetes:

Install kubernetes: yum install kubernetes using yum

After the kubernetes installation is successful, configure and start kubernetes:

The following components are required to run on kubernetes master:

1.kubernetes api server

2.kubernetes controller manager

3.kubernetes scheduler

The corresponding configuration file needs to be modified:

/ etc/kubernetes/apiserver: modify four parameters:

/ etc/kubernetes/config: modify a parameter:

After the modification is completed, start the service, and then set the boot self-startup:

[root@localhost ~] # systemctl enable kube-apiserver.service

Created symlink from / etc/systemd/system/multi-user.target.wants/kube-apiserver.service to / usr/lib/systemd/system/kube-apiserver.service.

[root@localhost ~] # systemctl start kube-apiserver.service

[root@localhost ~] # systemctl enable kube-controller-manager.service

Created symlink from / etc/systemd/system/multi-user.target.wants/kube-controller-manager.service to / usr/lib/systemd/system/kube-controller-manager.service.

[root@localhost ~] # systemctl start kube-controller-manager.service

[root@localhost ~] # systemctl enable kube-scheduler.service

Created symlink from / etc/systemd/system/multi-user.target.wants/kube-scheduler.service to / usr/lib/systemd/system/kube-scheduler.service.

[root@localhost ~] # systemctl start kube-scheduler.service

IV. Deploy k8s-node

1. Install docker strategy

2.nodeA node installs kubernetes: yum install kubernetes

Configure and start kubernetes:

The following components need to be run on k8s-node:

1.kubelet

2.kubernetes proxy

Two configuration files need to be modified accordingly:

Modify the kube_master address parameter in / etc/kubernetes/config:

Modify the three parameters in / etc/kubernetes/kubelet:

After the modification is completed, start the service and set the boot to start automatically:

[root@localhost ~] # systemctl enable kubelet.service

Created symlink from / etc/systemd/system/multi-user.target.wants/kubelet.service to / usr/lib/systemd/system/kubelet.service.

[root@localhost ~] # systemctl start kubelet.service

[root@localhost ~] # systemctl enable kube-proxy.service

Created symlink from / etc/systemd/system/multi-user.target.wants/kube-proxy.service to / usr/lib/systemd/system/kube-proxy.service.

[root@localhost ~] # systemctl start kube-proxy.service

After the node starts, check the master to see if the status is normal:

[root@localhost ~] # kubectl-s http://k8s-master:8080 get node

NAME STATUS AGE

K8s-nodea Ready 2m

[root@localhost ~] # kubectl get nodes

NAME STATUS AGE

K8s-nodea Ready 7m

Press nodeA on the node k8s-nodeB, and also install kubernetes:

After installing kubernetes successfully, press k8s-nodeA to modify the configuration:

After modifying the configuration, start the service and set the boot self-startup:

[root@localhost ~] # systemctl enable kubelet.service

Created symlink from / etc/systemd/system/multi-user.target.wants/kubelet.service to / usr/lib/systemd/system/kubelet.service.

[root@localhost ~] # systemctl start kubelet.service

[root@localhost ~] # systemctl enable kube-proxy.service

Created symlink from / etc/systemd/system/multi-user.target.wants/kube-proxy.service to / usr/lib/systemd/system/kube-proxy.service.

[root@localhost ~] # systemctl start kube-proxy.service

View the node and node status in the cluster on master:

Create a Flannel network

Install Flannel on k8s-master, k8s-nodeA, k8s-nodeB, and execute the command:

Yum install flannel

After successful installation, the configuration files on k8s-master, k8s-nodeA and k8s-nodeB are all modified to: / etc/sysconfig/flanneld

Configure the key about flannel in etcd in k8s-master:

[root@localhost ~] # etcdctl mk / atomic.io/network/config'{"Network": "192.0.0.0Univer 16"}'

{"Network": "192.0.0.0Can 16"}

Special note: Flannel uses Etcd for configuration to ensure configuration consistency among multiple Flannel instances, so you need to configure the following on etcd: (the key of'/ atomic.io/network/config' corresponds to the configuration item FLANNEL_ETCD_PREFIX in / etc/sysconfig/flannel above. If there is an error, startup will make an error)

After starting Flannel, you need to restart docker and kubernete in turn:

Execute on master:

Systemctl enable flanneld.service systemctl start flanneld.service service docker restartsystemctl restart kube-apiserver.servicesystemctl restart kube-controller-manager.servicesystemctl restart kube-scheduler.service

Execute on node:

Systemctl enable flanneld.service systemctl start flanneld.service service docker restartsystemctl restart kubelet.servicesystemctl restart kube-proxy.service

Installation and configuration complete

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Check the K8S version:

So much for sharing about how to build a kubernetes cluster environment in CentOS7. I hope the above content can be of some help and learn more knowledge. If you think the article is good, you can share it for more people to see.

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