# Learning Kubernetes

* A Kubernetes cluster consists of **Nodes** (simialr to servers)

* Nodes run **Pods**, which are collections of Docker containers. Containers in a Pod share the same network.

* The Kubernetes object responsible for launching and maintaining the desired number of pods is called a **Deployment**. 

* Kubernetes provides objects called a **Service** so thart Pods to communicate with other Pods. They are tied to Deployments through Selectors and Labels, and they can be exposed to external clients either by exposing a **NodePort** as a static port on each Kubernetes node or by creating a **LoadBalancer** object/

* Kubernetes provides the **Secret** object for managing sensitive information such as passwords, API keys, and other credentials.

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## Examples in this repository


* [Spin up a node server example](https://github.com/bt3gl/Learning_Kubernetes/tree/master/node-server-example).
* [Use kustomize to organize and combine YAML templates of your services and deployments](https://github.com/bt3gl/Learning_Kubernetes/tree/master/kustomize-example).


## Tools

### Minikube

[Minikube](https://github.com/kubernetes/minikube) implements a local Kubernetes cluster on macOS, Linux, and Windows. You can install it following [this instructions](https://minikube.sigs.k8s.io/docs/start/).


### Kubectl

Kubectl is a command line interface for running commands against Kubernetes clusters. You can install it [here](https://kubernetes.io/docs/tasks/tools/install-kubectl/).


#### **Pods**

Get pods:

    kubectl get pods -n <namespace>

Debug pods:

    kubectl describe pod <podname>

Get pod's log:

    kubectl logs <podname>

#### **Services**

Get services:

    kubectl get services -n <namespace>

#### **Deployments**

Get deployments:

    kubectl get deployment -n <namespace>

#### **Secrets**

    kubectl get secret

#### **Namespaces**

    kubectl get namespaces

#### **Configmaps**

    kubectl get configmaps -n <namespace>

#### **Ingress**

    kubectl get ingress -n <namespace>



### AWS Tools

* [AWS IAM authenticator](https://github.com/kubernetes-sigs/aws-iam-authenticator).


## References & Learning Resources

* [Google's K8s 101](https://techdevguide.withgoogle.com/paths/cloud/sequence-2/kubernetes-101-pods-nodes-containers-and-clusters/#!).
* [K8s Bootcamp](https://kubernetesbootcamp.github.io/kubernetes-bootcamp/).
* [K8s the Hard Way](https://github.com/kelseyhightower/kubernetes-the-hard-way#labs).