https://github.com/ratulsharker/k8-probes

Exploring kubernetes probes.
https://github.com/ratulsharker/k8-probes

docker express kubernetes liveliness nodejs probes readiness readiness-probe readiness-probes startup

Last synced: 2 months ago
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Exploring kubernetes probes.

• Host: GitHub
• URL: https://github.com/ratulsharker/k8-probes
• Owner: ratulSharker
• License: mit
• Created: 2023-11-27T09:53:13.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2025-05-05T05:25:32.000Z (about 1 year ago)
• Last Synced: 2025-12-06T19:47:47.208Z (6 months ago)
• Topics: docker, express, kubernetes, liveliness, nodejs, probes, readiness, readiness-probe, readiness-probes, startup
• Language: JavaScript
• Homepage:
• Size: 32.2 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
[![Dev.to blog](https://img.shields.io/badge/dev.to-0A0A0A?style=for-the-badge&logo=dev.to&logoColor=white)](https://dev.to/ratulsharker/my-understanding-was-wrong-about-readiness-and-liveliness-probes-1bl8) ![Docker](https://img.shields.io/badge/docker-%230db7ed.svg?style=for-the-badge&logo=docker&logoColor=white) ![Kubernetes](https://img.shields.io/badge/kubernetes-%23326ce5.svg?style=for-the-badge&logo=kubernetes&logoColor=white) ![NodeJS](https://img.shields.io/badge/node.js-6DA55F?style=for-the-badge&logo=node.js&logoColor=white) ![Express.js](https://img.shields.io/badge/express.js-%23404d59.svg?style=for-the-badge&logo=express&logoColor=%2361DAFB) [![Docker Image CI](https://github.com/ratulSharker/k8-probes/actions/workflows/docker-image-push.yml/badge.svg)](https://github.com/ratulSharker/k8-probes/actions/workflows/docker-image-push.yml)

# k8-probes 

## Blog post:

This repository is better accompanied with the blog post [My understanding was wrong about readiness and liveliness probes](https://dev.to/ratulsharker/my-understanding-was-wrong-about-readiness-and-liveliness-probes-1bl8) and [killercoda.com](https://killercoda.com)

## Background:

For better availability of services,  kubernetes offers three type of probes:

- Startup Probe.

- Readiness Probe.

- Liveliness Probe.

To accomodate exploring these probes, requires following:

- A simple rest service.

- Containerisation of the rest service.

- Kubernetes deployment definitions.

This repository covers all above points for exploring the kubernetes probes.

## Implementation details:

**Rest Service:**

- A simple nodejs + expressjs service.

- Exposed three routes `/liveliness`, `/readiness` & `/startup`.

- Each of these routes logs with timestamp.

- Each of these routes response code can be controlled via environment variables.

**Containersation:**

- Docker is used in containerisation of the rest service.

- Used [Dockerhub](https://hub.docker.com) to store the container image.

- `docker-compose.yaml` for local testing and image pushing into [Dockerhub](https://hub.docker.com).

**Kubernetes Deployment:**

- `playground` named namespace declared in the definition.

- Environments variables are configured for response codes for routes.

- Two different deployment files added, with `startup` probe and another without `startup` probe configured.