cka-lab：CKA考试的实验室环境

## Virtualbox lab environment for LFS258 Kubernetes Fundamentals training and practicing for CKA exams The Vagrant file creates following Ubuntu (Xenial) VMs - master(s), worker and load-balancer. Master nodes have been prepared for installing k8s cluster with ```kubeadm``` commands using [kubernetes\kubeadm-config.yaml](./kubernetes/kubeadm-config.yaml) file Load-balancer node has been prepared with: - simple haproxy configuration to test external access for k8s services exposed with nodePort - simple nfs export ```/opt/sfw/``` for testing persistent volumes ### Simpe lab diagram <img src="https://raw.githubusercontent.com/michalgutowski/cka-lab/master/lab-diagram.svg?sanitize=true"> ### Cluster networking: Internal IP addresses (you can copy the following to your ```/etc/hosts``` file): ```bash 192.168.56.100 ckalb 192.168.56.101 ckamaster1 ckamaster 192.168.56.102 ckamaster2 192.168.56.103 ckamaster3 192.168.56.104 ckaworker1 ``` Pod CIDR: ``` 10.244.0.0/16 (with Calico via enp0s8 interface) ``` ### Building clusters For most labs one master + one worker + additional lb/nfs node is enough. To initially build the cluster execute: ``` # vagrant up ckamaster1 ckaworker1 ckalb ``` All VMs will be created under CKA group in your Virtualbox. Once the cluster is up and running you can suspend it using: ``` # vagrant suspend ckamaster1 ckaworker1 ckalb ``` And later resume it whenever needed: ``` # vagrant resume ckamaster1 ckaworker1 ckalb ``` For the master HA labs you will need to build three masters + lb node ``` # vagrant up ckamaster1 ckamaster2 ckamaster3 ckalb ``` ### Connecting to cluster nodes You can connect to all nodes using student user and submiting the private key e.g.: ``` # ssh student@192.168.56.101 -i id_rsa ``` ### Installing k8s master In order to install first kubernetes master node connect to ckamaster1 and execute: ``` $ sudo -i # apt install docker.io kubeadm=1.15.1-00 kubectl=1.15.1-00 kubelet=1.15.1-00 # kubeadm init --config=kubeadm-config.yaml --upload-certs| tee kubeadm-init.out ``` Now it's your turn to figure how to add additional worker or master nodes. Have fun! ### Useful kubectl commands that helps you with creating objects Creating a deployment ```$ kubectl run``` Creating a pod ```$ kubectl run --restart=Never``` Creating a job ```$ kubectl run --restart=OnFailure``` Creating a cronjob ```$ kubectl run --restart=OnFailure --schedule=“* * * * *”``` #### Notes - Passwordless ssh has been configured between nodes using root user - Password for user **student**: **welcome1** Tested on MacOS 10.14.6 (Mojave), Vagrant 2.2.5 and VirtualBox 6.0.8, Ubuntu/Xenial vagrant box v. 20191114.0.0. Min. 16GB of RAM recommended.