k8-probes

Blog post:

This repository is better accompanied with the blog post My understanding was wrong about readiness and liveliness probes and 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 to store the container image.
• docker-compose.yaml for local testing and image pushing into Dockerhub.

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.