by: Alaa Atwa

from Ahmed elfakhrany ‘s Udemy course and other resources

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course link: https://www.udemy.com/course/kubernetes-from-beginner-to-master-arabic

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right click and disable check spelling for better experience 🤓

• if you are new to notion, don’t forget to click the toggle list which looks like this :
  • click.the.toggle.sign.please
• hover over the right section of the page to see a list of the page ‘s content. </aside>

intro

Orchestrator : the brain that automates deployment, scaling, networking, and lifecycle management of containers.(control plane in k8s)

cluster : a group of machines running k8s, managed as one unit.

node: one machine from the cluster (one virtual machine), runs containers and the necessary services.

cluster components

• the cluster consists of control plane(one or more Linux nodes) and data plane(one or more nodes running linux or windows)
• locally the master node and working nodes runs together on the same machine
• the control plane has:

1. an API that receives the requests.
2. an etcd database to save requests (must have an odd number of nodes).
3. controller manager (c-m) create and control the pods inside the node (like deployment, replicaset,…etc) all of theses are controller managers.
4. scheduler organize and assigns pods to nodes
5. cloud controller manager (c-c-m)

• the data plane has:

1. kubelet : managing and running containers on each working node. (receives and send requests with the api).
2. runtime (containerd or cr-o) : manages the containers directly (pulls and creates..), no interaction with it.
3. kube-proxy : network component to run on each k8s node (e.g. manage rules for service routing)

kubeconfig

• a config file for kubectl to access and manage k8s clusters.

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kubeconfig file usually saved here —> ~/.kube/config

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apiVersion: v1
kind: Config    # notice the kind 
clusters:
	# if you installed minikube, it will be mentioned here
	- name: mycluster
		cluster: 
			server: https://....
			certificate-authority-data: .... # (CA)
users: 
	- name: kubeadmin
		user:
			client-certificate-data: ....