Kubernetes

Updated: 24 February 2025

Example with Minikube

Convert docker compose config to Kubernetes cofig and apply it to Kubernetes

#!/bin/bash

cd  /path/to/docker-compose-project/

# make a dir for kompose output yaml files
rm -rf kompose-output
mkdir kompose-output
cd kompose-output

# convert docker compose file to kubernetes files
kompose --file ../docker-compose.yml convert

# apply to minikube all the config files
# this actually runs the containers in kubernetes
minikube kubectl -- apply -f '*.yaml'

Check that deployments are running

minikube kubectl -- get deployments

Get the name of the service with type LoadBalancer

minikube kubectl -- get services

On cloud providers supporting load balancers, an external IP address would be provisioned to access the Service. On minikube, the LoadBalancer type makes the Service accessible through the minikube service command.

Opens a browser window that serves the app

minikube service name-of-loadbalancer-service

Updated: 23 February 2025

View a list of deployments

kubectl get deployment

View services

kubectl get services

View a list of pods

kubectl get pods

View application logs for a container in a pod

kubectl logs hello-node-5f76cf6ccf-br9b5

View cluster events

kubectl get events

Clean up resources created for a cluster

kubectl delete service hello-node
kubectl delete deployment hello-node

Updated: 23 February 2025

Start a local Kubernetes cluster

minikube start

Access the Kubernetes dashboard, running within the minikube cluster

minikube dashboard

Show the dashboard url, without opening a browser

minikube dashboard --url

minikube includes kubectl which can be used like this

minikube kubectl -- <kubectl commands>

Stop a Minikube cluster

minikube stop

Optionally, delete the Minikube VM

minikube delete

Updated: 24 February 2025

Kubernetes is the most popular way to deploy, run and manage containers in production.

• Hosting microservices in their own containers is a common pattern for microservice-based development. It’s not uncommon to have many different microservices composing a single application.
• A container orchestrator is a system that automatically deploys and manages containerized apps. For example, the orchestrator can dynamically respond to changes in the environment to increase or decrease the deployed instances of the managed app. It can also ensure all deployed container instances get updated if a new version of a service is released.
• Kubernetes abstracts away complex container management tasks, and provides you with declarative configuration to orchestrate containers in different computing environments.

See Deploy a .NET microservice to Kubernetes

k8s

An abbreviation for Kubernetes

Helm

The k8s package manager

minikube

Local Kubernetes, focusing on making it easy to learn and develop for Kubernetes.

Pod

One or more Containers, tied together for the purposes of administration and networking. By default a Pod is only accessible by its internal IP address within the Kubernetes cluster. To make a Container accessible from outside the Kubernetes virtual network, expose the Pod as a Kubernetes Service.

Deployment

A Kubernetes Deployment checks on the health of a Pod and restarts the Pod’s Container if it terminates. Deployments are the recommended way to manage the creation and scaling of Pods.

StatefulSets

StatefulSets maintain the state of applications beyond an individual pod lifecycle.