containersolutions/kubernetes-examples

Minimal self-contained examples of standard Kubernetes features and patterns in YAML

Kubernetes Examples

A reference repository of YAML with canonical and as-simple-as-possible demonstrations of kubernetes functionality and features.

See here for a searchable front-end: https://k8s-examples.container-solutions.com/

Why?

At Container Solutions we find we regularly need chunks of YAML to demonstrate something specific, such as:

• A simple deployment

• A simple pod

• A pod with a volume

This might be to do a basic test of an environment, find an example to tinker with, or send to someone to get them going.

Usage

The examples can be used by a kubectl plugin examples. This plugin can be installed by krew:

• first install krew
• Install a custom plugin index: kubectl krew index add cs https://github.com/ContainerSolutions/kubernetes-examples.git
• Install this plugin: kubectl krew install cs/examples

Interactively discover by first selecting the resource type:

$ kubectl examples

filter by resource type

$ kubectl examples Service

filter by resource type and pattern

$ kubectl examples Pod res

If there is only a single match selected by the parameters, it is printed to the stdout. So you can deploy a modified version of a sample by:

$ export KUBE_EDITOR='code -w'
$ kubectl examples Ingress fanout | kubectl create -f - --edit

Sections

broken-* - yamls that exemplify broken kubernetes yaml states

[A-Z][a-zA-Z]* - Example yamls that correspond to resource types.

test - Scripts to test or validate the YAML

Within those folders are either simple/canonical examples, or examples in subfolders that expose particular items of functionality that are highlighted by their yaml path, eg Pod/spec.initContainers/.

If an example is an exemplar of a particular feature but tightly related to another resource, then an absolute folder might be added eg in Service there is Service/Pod.spec.subdomain.

Symlinks are also used to make finding things easier, eg Service/headless-service -> Service/spec.clusterIP.

plugins - a directory following the spec for a Custom krew plugin index

Principles

The examples seek to be:

• As simple as possible to illustrate the functionality

• Self-contained (ie limited to one .yaml file)

• Non-conflicting (eg resource names are unique)

• Clear (eg resource names are verbose and unambiguous)

Release Process

See here

Sources / Thanks To

Official Kubernetes docs

Kubernetes by Example

Practical Kubernetes

Security Examples

kubernetes-examples's Issues

Add PriorityClass Example

We're missing an example for PriorityClass.

It should be possible to use an example from the Kubernetes docs.

If you want to pick up this issue, please first read the README.md and CONTRIBUTING.md. Make sure you follow the existing style and standards for other examples.

Update CI for unmaintained dependencies.

our CI process uses https://github.com/instrumenta/kubernetes-json-schema/ to validate any schemas, however it seems this project is no longer being maintained.

We need to update CI with a new way to check for validation of the yaml files.

Create a branch per kubernetes version

This is a precursor to auto-testing the examples against these versions. API versions can change between releases.

Check and update all previous examples to the latest APIs

• ClusterRole
• ClusterRoleBinding
• ConfigMap
• CronJob
• DaemonSet
• Deployment
• EndpointSlice
• Ingress
• Job
• LimitRange
• Namespace
• NetworkPolicy
• PersistentVolume
• PersistentVolumeClaim
• Pod
• PodDisruptionBudget
• PodSecurityPolicy
• PriorityClass
• ResourceQuotas
• Role
• RoleBinding
• Secret
• Service
• ServiceAccount
• StatefulSet
• StorageClass
• broken-Pod
• broken-Secret
• broken-Deployment

readiness probe

One with a nice readiness probe and one with a broken one ?

Check/update documentation

• Check documentation if there is anything missing for a new contributor perspective.
• Steps for local testing with local cluster

Submit as a krew plugin

Submit as an official krew plugin: https://krew.sigs.k8s.io/docs/developer-guide/release/new-plugin/

Update External Resource API Versions

• Plugins
• Cloud Providers

Update Kubernetes example website

https://k8s-examples.container-solutions.com/

Add example for EndpointSlice

We're missing an example for EndpointSlices, but we do have one for Endpoints. This example could go in the same directory or a new one.

It should be possible to use the example from here: https://kubernetes.io/docs/concepts/services-networking/endpoint-slices/

If you want to pick up this issue, please first read the README.md and CONTRIBUTING.md. Make sure you follow the existing style and standards for other examples.

Validate istio schemas

--ignore-missing-schema was added to kubeconform to stop CI from failing for istio examples. It would be nice to have validation for istio schemas

Identify resources still TODO

• Identify top-level resources that are still TODO

• EndpointSlice
• CSIDriver
• CSINode
• VolumeAttachment
• PersistentVolumeClaim
• ControllerRevision
• ControllerRevisionList
• CustomResourceDefinition – simplest example done: #48 ; TODO: add a custom resource being used example
• Event
• HorizontalPodAutoscalar
• ValidatingAdmissionWebhook
• MutatingAdmissionWebhook
• PodDisruptionBudget
• PriorityClass
• PodPreset

• Create folders for these with a README.md in each (empty is OK for now)

Add PodDisruptionBudget Example

We're missing an example for PodDisruptionBudget.

It should be possible to use an example from the Kubernetes docs.

If you want to pick up this issue, please first read the README.md and CONTRIBUTING.md. Make sure you follow the existing style and standards for other examples.

Add PodPreset Example

We're missing an example for PodPreset.

It should be possible to use an example from the Kubernetes docs.

If you want to pick up this issue, please first read the README.md and CONTRIBUTING.md. Make sure you follow the existing style and standards for other examples.

Add AdmissionWebhook Examples

Add examples for ValidatingAdmissionWebhook and MutatingAdmissionWebhook.

It should be possible to use examples from the Kubernetes docs, but please make sure they work standalone.

If you want to pick up this issue, please first read the README.md and CONTRIBUTING.md. Make sure you follow the existing style and standards for other examples.

Remove PodSecurityPolicy examples

PodSecurityPolicy is deprecated and will be removed from Kubernetes API in 1.25 release. We should remove the examples when it's removed from the API.

Add example for PersistentVolumeClaim

We're missing an example for PersistentVolumeClaim, but we do have one for PersistentVolumes. This example should probably go in the same directory.

It should be possible to use an example from the Kubernetes docs, but please make sure it works either standalone or with the existing PersistentVolume example.

If you want to pick up this issue, please first read the README.md and CONTRIBUTING.md. Make sure you follow the existing style and standards for other examples.

Validate missing schemas

--ignore-missing-schema was added to kubeconform to stop CI from failing for istio examples. This flag could be removed and istio resources can be ignored

Automate the release process

Hi there.

We have found some differences between the main branch and the released github pages with the resource examples.
For example: Ingress resource example page vs Ingress resource example in master branch. Latest release done was done in May 2021.

This ticket is to rethink the release process and automate it if viable.

Create template for new issues

For new issues, template should be created so that description would cover some basic questions like:
Bug or Feature Request/New Example Request
Bug: Which examples are affected?
Feature Request/New Example Request: Name of the resource kind and resource example is asked for

Add HorizontalPodAutoscaler Example

We're missing an example for HorizontalPodAutoscalar.

It should be possible to use an example from the Kubernetes docs.

If you want to pick up this issue, please first read the README.md and CONTRIBUTING.md. Make sure you follow the existing style and standards for other examples.