Kubernetes
##########

Install K3S
***********

https://github.com/k3s-io/k3s#quick-start---install-script


Install K9S (CLI UI for Kubernetes Management)
**********************************************

.. code-block:: bash
   
   wget https://github.com/derailed/k9s/releases/download/v0.40.9/k9s_linux_amd64.deb # Or respective current version
   sudo dpkg --install k9s_linux_amd64.deb


Connect to Cluster
******************

If you run your cluster localy, ignore this step.

You can either connect to one of the cluster nodes through ssh and execute commands from there, or setup kubernetes to execute kubectl commands remotly on the cluster.
To tell kubectl where to connect to, you need to edit ~/.kube/config

.. code-block:: bash

   apiVersion: v1
   kind: Config

   clusters:
   - cluster:
       server: https://<ip-of-cluster>:<port>
     name: my-dev-cluster

   users:
   - name: IAM#....<cluster-url>:<port>
     user:
       token: sha256-******

   contexts:
   - context:
     name: my-dev-cluster


.. code-block:: bash

   kubectl config use-context my-dev-cluster


Usefull commands
****************

Nodes
-----

.. code-block:: bash

   # Show basic info for all nodes
   sudo kubectl get nodes

   # Show detailed info for all nodes
   sudo kubectl describe nodes


Pods
----

.. code-block:: bash

   # Get all pods
   sudo kubectl get pods -A


Deployment
----------

.. code-block:: bash

   # Create a new deployment
   sudo kubectl create deployment <name-of-deployment> --image=<registry-ip>:<port>/<image>

   # Remove deployment
   sudo kubectl delete deployment <name-of-deployment>

   # Scale Deployment
   sudo kubectl scale deployments/<name-of-deployment> --replicas=3

   # Show details of the specified deployment
   sudo kubectl describe pod -l app=<application/deployment>


K8S
===

.. code-block:: bash

   git clone https://github.com/kubernetes/kubernetes
   cd kubernetes
   make quick-release



.. code-block:: bash

   sudo snap install microk8s --classic

   microk8s status --wait-ready
   microk8s enable dashboard dns registry istio
   
   # Show Infos about Kubernetes
   microk8s kubectl get all --all-namespaces

   microk8s dashboard-proxy