Kubernetes, KOPS and Helm
What is Kubernetes?
Also known as k8s or kube
API based system that makes Docker containers reliable & scalable
by Google
Desired cluster state management tool
Basic concept of Kubernetes
Node
Hosts running k8s daemons
Example: EC2 instance on AWS
Cluster
Pod
Basic unit of deployment in k8s
Pod
- Group of Docker containers (i.e. php + nginx)
- Container configurations (i.e. environment variables)
- Shared storage (i.e. /sites/default/files in Drupal)
- Expected to be stateless
- Always located on the same Node
Pod
Pod
All Docker containers within the same pods are guaranteed to be on the same server
Pod
Replica Set
Ensures that a specified number of Pod replicas are running at any given time.
Replica Set
Replica Set
Replica Set
Replica Set
Deployment
Is used to change the current state to the desired state.
Wraps around Pods and Replica Sets
Deployment
Deployment
Deployment
Deployment
Services
A "proxy" way to access Pods
Services
Services
Services
Services
Service
Ingress
Service, but for the cluster
Namespace
A virtual cluster inside of physical cluster
Job
Is used to perform some task and exit after successfully completing their work or after a given period of time
KOPS
Kubernetes OPerationS
KOPS
HELM
Package manager for Kubernetes
HELM CONCEPT
- Charts
- Releases
Chart
Collection of kubernetes building blocks (pods, deployments, services, etc) powered by templating language
Release
A name of the Chart deployed to kubernetes
