Setting up a Kubernetes cluster with Vagrant

Using vagrant file to build a kubernetes cluster which consists of 1 master(also as node) and 3 nodes. You don't have to create complicated ca files or configuration.

See in GitHub

Using vagrant file to build a kubernetes cluster which consists of 1 master(also as node) and 3 nodes. You don’t have to create complicated ca files or configuration.

Why don’t we use kubeadm

Because I want to setup the etcd, apiserver, controller, scheduler without docker container.

Architecture

We will create a Kubernetes 1.9.1+ cluster with 3 nodes which contains the components below:

IP Hostname Componets
172.17.8.101 node1 kube-apiserver, kube-controller-manager, kube-scheduler, etcd, kubelet, docker, flannel, dashboard
172.17.8.102 node2 kubelet, docker, flannel、traefik
172.17.8.103 node3 kubelet, docker, flannel

The default setting will create the private network from 172.17.8.101 to 172.17.8.103 for nodes, and it will use the host’s DHCP for the public ip.

The kubernetes service’s vip range is 10.254.0.0/16.

The container network range is 170.33.0.0/16 owned by flanneld with host-gw backend.

kube-proxy will use ipvs mode.

Usage

Prerequisite

  • Host server with 8G+ mem(More is better), 60G disk, 8 core cpu at lease
  • vagrant 2.0+
  • virtualbox 5.0+
  • Maybe need to access the internet through GFW to download the kubernetes files

Support Addon

Required

  • CoreDNS
  • Dashboard
  • Traefik

Optional

  • Heapster + InfluxDB + Grafana
  • ElasticSearch + Fluentd + Kibana
  • Istio service mesh
  • Helm

Setup

Download kubernetes binary release first and move them to this git repo.

git clone https://github.com/rootsongjc/kubernetes-vagrant-centos-cluster.git
cd kubernetes-vagrant-centos-cluster
vagrant up

Before you run vagrant up make sure this repo directory include the flowing files:

  • kubernetes-client-linux-amd64.tar.gz
  • kubernetes-server-linux-amd64.tar.gz

Wait about 10 minutes the kubernetes cluster will be setup automatically.

Note

If you have difficult to vagrant up the cluster because of have no way to downlaod the centos/7 box, you can download the box and add it first.

Add centos/7 box manually

wget -c http://cloud.centos.org/centos/7/vagrant/x86_64/images/CentOS-7-x86_64-Vagrant-1801_02.VirtualBox.box
vagrant box add CentOS-7-x86_64-Vagrant-1801_02.VirtualBox.box --name centos/7

The next time you run vagrant up, vagrant will import the local box automatically.

Connect to kubernetes cluster

There are 3 ways to access the kubernetes cluster.

local

Copy conf/admin.kubeconfig to ~/.kube/config, using kubectl CLI to access the cluster.

mkdir -p ~/.kube
cp conf/admin.kubeconfig ~/.kube/config

We recommend this way.

VM

Login to the virtual machine to access and debug the cluster.

vagrant ssh node1
sudo -i
kubectl get nodes

Kubernetes dashbaord

Kubernetes dashboard URL: https://172.17.8.101:8443

Get the token:

kubectl -n kube-system describe secret `kubectl -n kube-system get secret|grep admin-token|cut -d " " -f1`|grep "token:"|tr -s " "|cut -d " " -f2

Note: You can see the token message from vagrant up logs.

Components installed

Heapster monitoring

Run this command on you local machine.

kubectl apply -f addon/heapster/

Append the following item to you local /etc/hosts file.

172.17.8.102 grafana.jimmysong.io

Open the URL in your browser: http://grafana.jimmysong.io

Treafik ingress

Run this command on you local machine.

kubectl apply -f addon/traefik-ingress

Append the following item to you local /etc/hosts file.

172.17.8.102 traefik.jimmysong.io

Traefik UI URL: http://traefik.jimmysong.io

EFK

Run this command on your local machine.

kubectl apply -f addon/heapster/

Note: Powerful CPU and memory allocation required. At least 4G per virtual machine.

Helm

Run this command on your local machine.

hack/deploy-helm.sh

Service Mesh

We use istio as the default service mesh.

Installation

kubectl apply -f addon/istio/

Run sample

kubectl apply -n default -f <(istioctl kube-inject -f yaml/istio-bookinfo/bookinfo.yaml)

Add the following items into /etc/hosts in your local machine.

172.17.8.102 grafana.istio.jimmysong.io
172.17.8.102 servicegraph.istio.jimmysong.io
172.17.8.102 zipkin.istio.jimmysong.io

We can see the services from the following URLs.

Service URL
grafana http://grafana.istio.jimmysong.io
servicegraph http://servicegraph.istio.jimmysong.io/dotviz, http://servicegraph.istio.jimmysong.io/graph
zipkin http://zipkin.istio.jimmysong.io
productpage http://172.17.8.101:32000/productpage

More detail see https://istio.io/docs/guides/bookinfo.html

Operation

Except for special claim, execute the following commands under the current git repo root directory.

Suspend

Suspend the current state of VMs.

vagrant suspend

Resume

Resume the last state of VMs.

vagrant resume

Note: every time you resume the VMs you will find that the machine time is still at you last time you suspended it. So consider to halt the VMs and restart them.

Restart

Halt the VMs and up them again.

vagrant halt
vagrant up
# login to node1
vagrant ssh node1
# run the prosivision scripts
/vagrant/hack/k8s-init.sh
exit
# login to node2
vagrant ssh node2
# run the prosivision scripts
/vagrant/hack/k8s-init.sh
exit
# login to node3
vagrant ssh node3
# run the prosivision scripts
/vagrant/hack/k8s-init.sh
sudo -i
cd /vagrant/hack
./deploy-base-services.sh
exit

Now you have provisioned the base kubernetes environments and you can login to kubernetes dashboard, run the following command at the root of this repo to get the admin token.

hack/get-dashboard-token.sh

Following the hint to login.

Clean

Clean up the VMs.

vagrant destroy
rm -rf .vagrant

Note

Only use for development and test, don’t use it in production environment.

Reference