Learn KUBELESS with Real Code Examples

Kubeless is built on Kubernetes and uses custom resources to define functions as first-class objects.

Supports multiple runtimes including Python, Node.js, Go, and Ruby.

Integrates with Kubernetes services like Ingress, Secrets, and ConfigMaps.

Enables auto-scaling based on resource usage and events.

Designed to simplify function deployment while taking full advantage of Kubernetes features.

Serverless function deployment on Kubernetes

Auto-scaling functions based on demand

Event triggers for HTTP, message queues, and timers

Native Kubernetes integration (Secrets, ConfigMaps, Services)

Monitoring via Prometheus and Kubernetes metrics

Function - smallest deployable unit, triggered by events

Trigger - defines when a function should run

Runtime - language environment for the function (Python, Node.js, etc.)

Namespace - Kubernetes scope for functions and resources

Custom Resource Definitions - define functions as Kubernetes objects

functions/ - contains source code for each function

triggers/ - YAML definitions for event triggers

deploy/ - manifests for Kubeless controllers and CRDs

scripts/ - CLI or automation scripts

README.md - documentation and usage instructions

Write function code in supported runtime

Create YAML definition or use CLI to deploy function

Define triggers (HTTP, message queues, cron) for the function

Deploy function to Kubernetes cluster

Test function by invoking triggers or HTTP endpoints

Beginner: deploy simple HTTP function

Intermediate: event-driven function triggered by Kafka/NATS

Advanced: multiple functions with dependencies and secrets

Expert: CI/CD pipelines with serverless Kubernetes integration

Auditor: monitor and optimize function performance

Kubeless vs AWS Lambda: Lambda is managed; Kubeless requires Kubernetes

Kubeless vs OpenFaaS: Kubeless is Kubernetes-native; OpenFaaS adds UI and auto-scaling features

Kubeless vs Knative: Knative has more features, Kubeless is lightweight

Kubeless vs Fission: Both Kubernetes-native; Fission provides faster cold-start optimization

Kubeless vs Cloud Functions: Kubeless is self-hosted and flexible, Cloud Functions are managed

2016 – Kubeless initial release by Bitnami

2017 – Added multiple runtime support

2018 – Improved event triggers and Cron support

2019 – Integration with Prometheus metrics

2020–2023 – Maintenance releases and Kubernetes compatibility updates

Function - single-purpose, deployable code unit

Trigger - event source that invokes a function

Runtime - environment in which the function executes

Custom Resource Definition - Kubernetes resource type

Namespace - Kubernetes scope for function deployment