Learn OPENFAAS with Real Code Examples

OpenFaaS allows developers to deploy any code as serverless functions using Docker containers.

It provides an event-driven architecture with support for HTTP, queues, and cron triggers.

Supports automatic scaling based on demand (including scale-to-zero).

Integrates with Kubernetes, Docker Swarm, or local deployments for portability.

Used for microservices, automation, cloud-native apps, and event-driven workflows.

Function templates for multiple languages

Web UI and CLI for management

Built-in metrics and Prometheus integration

Asynchronous and synchronous function invocation

Multi-cloud portability

Function - the unit of compute

Gateway - API entry point for invoking functions

Template - starter code for a function in a specific language

Trigger - event source (HTTP, queue, cron)

Autoscaling - dynamically adjusting replicas based on load

stack.yml - defines functions and configurations

handler/ - function code

template/ - function templates

Dockerfile - build instructions for function container

faas-cli commands - build, push, deploy, invoke

Choose a function template for your language

Build the function using `faas-cli build`

Push container image to registry with `faas-cli push`

Deploy function to OpenFaaS with `faas-cli deploy`

Invoke function via CLI, HTTP, or event trigger

Beginner: simple HTTP-triggered function

Intermediate: function triggered by message queue

Advanced: multiple interconnected microservices

Expert: scalable event-driven architecture

Architect: hybrid multi-cloud serverless workflows

OpenFaaS vs AWS Lambda: vendor-neutral vs AWS-native

OpenFaaS vs Knative: simpler setup vs Kubernetes-native standard

OpenFaaS vs Serverless Framework: lightweight vs multi-provider abstraction

OpenFaaS vs Kubeless: more community support vs Kubernetes-native

OpenFaaS vs Azure Functions: cloud-agnostic vs Azure-native serverless

2016 – Initial release of OpenFaaS

2017–2018 – Added Kubernetes support and templates

2019–2020 – Prometheus integration and async support

2021–2023 – Multi-architecture images and edge deployments

2024–2025 – Enhanced monitoring, observability, and security features

Function - unit of compute

Gateway - API entry point

Template - starter code for functions

Trigger - event source for function invocation

Autoscaling - dynamic replica adjustment