# Kubernetes & Docker

Kubernetes is a container orchestration framework that helps with managing applications requiring one or more container. You create a cluster which holds nodes which holds pods.

Pods that are running inside Kubernetes are running on a private, isolated network. By default they are visible from other pods and services within the same Kubernetes cluster, but not outside that network. When we use `kubectl`, we're interacting through an API endpoint to communicate with apps.

## Kubernetes

```
minikube version
minikube start
kubectl version 
kubectl cluster-info
kubectl get #List resources
kubectl get nodes
kubectl describe  #Show details
kubectl logs #Print logs from a container in a pod
kubectl get pods
kubectl exec POD-NAME -- whoami #Execute command on a container in a pod
kubectl exec -ti POD-NAME -- /bin/bash #Execute command on a container in a pod

kubectl create deployment DEPLOYMENT-NAME --image=DOCKER-IMAGE/DOCK-USER:latest
kubectl get deployments

```

### Pods, nodes, and deployments

When deploying, Kubernetes creates a **Pod** to host your application instance. A Pod is a Kubernetes abstraction that represents a group of one or more application containers (such as Docker), and some shared resources for those containers. Those resources include:

* Shared storage, as Volumes
* Networking, as a unique cluster IP address
* Information about how to run each container, such as the container image version or specific ports to use

{% hint style="info" %}
Learn more here:\
<https://kubernetes.io/docs/tutorials/kubernetes-basics/explore/explore-intro/>
{% endhint %}

{% hint style="info" %}
When deploying an app through kubectl, Kubernetes will do a couple of things:

* searched for a suitable node where an instance of the application could be run (we have only 1 available node)
* scheduled the application to run on that Node
* configured the cluster to reschedule the instance on a new Node when needed
  {% endhint %}

## Docker

```
docker login #Credentials 
docker pull DOCKER-IMAGE/DOCK-USER:latest

```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://book.turbosec.net/kubernetes-and-docker.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.