Learn Openfaas - 10 Code Examples & CST Typing Practice Test

OpenFaaS (Functions as a Service) is an open-source serverless framework for building and deploying functions or microservices with Docker and Kubernetes. It focuses on simplicity, portability, and scaling workloads automatically.

View all 10 Openfaas code examples →

Simple OpenFaaS Function OpenFaaS Function with Environment Variables OpenFaaS Function with Labels OpenFaaS Function with Annotations OpenFaaS Function with Secrets OpenFaaS Function with Custom Constraints OpenFaaS Function with Multiple Topics OpenFaaS Function with Resource Limits OpenFaaS Function with Auto-scaling OpenFaaS Function with Readiness and Liveness Probes

Learn OPENFAAS with Real Code Examples

Updated Nov 25, 2025

Introduction & Fundamentals Setup & Configuration Architecture & Deep Internals Performance & Security Development Workflow Learning & Career Growth Business & Strategy Examples

Code Sample Descriptions

Simple OpenFaaS Function

# openfaas/demo/function.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    hello-python:
        lang: python3
        handler: ./handler
        topic: http
        image: hello-python:latest

A simple OpenFaaS YAML configuration to deploy a Python HTTP function.

Let’s Try →

OpenFaaS Function with Environment Variables

# openfaas/demo/env.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    env-demo:
        lang: python3
        handler: ./handler
        envVars:
        GREETING: "Hello OpenFaaS"
        image: env-demo:latest

Deploy a function with custom environment variables.

Let’s Try →

OpenFaaS Function with Labels

# openfaas/demo/labels.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    label-demo:
        lang: python3
        handler: ./handler
        labels:
        team: devops
        env: staging
        image: label-demo:latest

Add metadata labels to an OpenFaaS function.

Let’s Try →

OpenFaaS Function with Annotations

# openfaas/demo/annotations.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    annotation-demo:
        lang: python3
        handler: ./handler
        annotations:
        com.openfaas.scale.min: "1"
        com.openfaas.scale.max: "5"
        image: annotation-demo:latest

Configure OpenFaaS function annotations for monitoring or routing.

Let’s Try →

OpenFaaS Function with Secrets

# openfaas/demo/secrets.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    secret-demo:
        lang: python3
        handler: ./handler
        secrets:
        DB_PASSWORD
        image: secret-demo:latest

Use OpenFaaS secrets in your function deployment.

Let’s Try →

OpenFaaS Function with Custom Constraints

# openfaas/demo/constraints.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    constraint-demo:
        lang: python3
        handler: ./handler
        constraints:
        node.role == worker
        image: constraint-demo:latest

Apply deployment constraints to schedule functions on specific nodes.

Let’s Try →

OpenFaaS Function with Multiple Topics

# openfaas/demo/topics.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    topic-demo:
        lang: python3
        handler: ./handler
        topic: topic1,topic2
        image: topic-demo:latest

Subscribe a function to multiple topics for event-driven processing.

Let’s Try →

OpenFaaS Function with Resource Limits

# openfaas/demo/resources.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    resource-demo:
        lang: python3
        handler: ./handler
        limits:
        memory: "128Mi"
        cpu: "500m"
        image: resource-demo:latest

Specify CPU and memory limits for an OpenFaaS function.

Let’s Try →

OpenFaaS Function with Auto-scaling

# openfaas/demo/autoscale.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    autoscale-demo:
        lang: python3
        handler: ./handler
        annotations:
        com.openfaas.scale.min: "2"
        com.openfaas.scale.max: "10"
        image: autoscale-demo:latest

Enable OpenFaaS auto-scaling with min/max replicas.

Let’s Try →

OpenFaaS Function with Readiness and Liveness Probes

# openfaas/demo/probes.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    probe-demo:
        lang: python3
        handler: ./handler
        readinessProbe:
        httpGet:
        path: /health
        port: 8080
        livenessProbe:
        httpGet:
        path: /health
        port: 8080
        image: probe-demo:latest

Configure readiness and liveness probes for OpenFaaS functions.

Let’s Try →

Frequently Asked Questions about Openfaas

What is Openfaas?

What are the primary use cases for Openfaas?

Deploying event-driven serverless functions. Microservices backends. Automating DevOps and CI/CD pipelines. Edge computing and IoT workloads. Data processing tasks and cron jobs

What are the strengths of Openfaas?

Easy to deploy functions in Docker/Kubernetes. Vendor-neutral serverless solution. Rapid scaling and scale-to-zero for cost savings. Supports multiple programming languages. Simplifies CI/CD automation and event-driven workflows

What are the limitations of Openfaas?

Requires containerization knowledge. Less mature ecosystem compared to AWS Lambda. Performance depends on container startup time. Complex orchestration for large-scale deployments. Monitoring and debugging can be challenging for many functions

How can I practice Openfaas typing speed?

CodeSpeedTest offers 10+ real Openfaas code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.

Learn Other Programming Languages

C React Python C++Rust TypeScript Kotlin PHP Java C#Ruby Mql Cql N1ql Cypher Gremlin Partiql Haskell Elixir Fsharp View all languages →

Code Sample Descriptions

Simple OpenFaaS Function

# openfaas/demo/function.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    hello-python:
        lang: python3
        handler: ./handler
        topic: http
        image: hello-python:latest

A simple OpenFaaS YAML configuration to deploy a Python HTTP function.

Let’s Try →

OpenFaaS Function with Environment Variables

# openfaas/demo/env.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    env-demo:
        lang: python3
        handler: ./handler
        envVars:
        GREETING: "Hello OpenFaaS"
        image: env-demo:latest

Deploy a function with custom environment variables.

Let’s Try →

OpenFaaS Function with Labels

# openfaas/demo/labels.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    label-demo:
        lang: python3
        handler: ./handler
        labels:
        team: devops
        env: staging
        image: label-demo:latest

Add metadata labels to an OpenFaaS function.

Let’s Try →

OpenFaaS Function with Annotations

# openfaas/demo/annotations.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    annotation-demo:
        lang: python3
        handler: ./handler
        annotations:
        com.openfaas.scale.min: "1"
        com.openfaas.scale.max: "5"
        image: annotation-demo:latest

Configure OpenFaaS function annotations for monitoring or routing.

Let’s Try →

OpenFaaS Function with Secrets

# openfaas/demo/secrets.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    secret-demo:
        lang: python3
        handler: ./handler
        secrets:
        DB_PASSWORD
        image: secret-demo:latest

Use OpenFaaS secrets in your function deployment.

Let’s Try →

OpenFaaS Function with Custom Constraints

# openfaas/demo/constraints.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    constraint-demo:
        lang: python3
        handler: ./handler
        constraints:
        node.role == worker
        image: constraint-demo:latest

Apply deployment constraints to schedule functions on specific nodes.

Let’s Try →

OpenFaaS Function with Multiple Topics

# openfaas/demo/topics.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    topic-demo:
        lang: python3
        handler: ./handler
        topic: topic1,topic2
        image: topic-demo:latest

Subscribe a function to multiple topics for event-driven processing.

Let’s Try →

OpenFaaS Function with Resource Limits

# openfaas/demo/resources.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    resource-demo:
        lang: python3
        handler: ./handler
        limits:
        memory: "128Mi"
        cpu: "500m"
        image: resource-demo:latest

Specify CPU and memory limits for an OpenFaaS function.

Let’s Try →

OpenFaaS Function with Auto-scaling

# openfaas/demo/autoscale.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    autoscale-demo:
        lang: python3
        handler: ./handler
        annotations:
        com.openfaas.scale.min: "2"
        com.openfaas.scale.max: "10"
        image: autoscale-demo:latest

Enable OpenFaaS auto-scaling with min/max replicas.

Let’s Try →

OpenFaaS Function with Readiness and Liveness Probes

# openfaas/demo/probes.yml
provider:
    name: openfaas
    gateway: http://127.0.0.1:8080
functions:
    probe-demo:
        lang: python3
        handler: ./handler
        readinessProbe:
        httpGet:
        path: /health
        port: 8080
        livenessProbe:
        httpGet:
        path: /health
        port: 8080
        image: probe-demo:latest

Configure readiness and liveness probes for OpenFaaS functions.

Let’s Try →

Frequently Asked Questions about Openfaas

What is Openfaas?

What are the primary use cases for Openfaas?

Deploying event-driven serverless functions. Microservices backends. Automating DevOps and CI/CD pipelines. Edge computing and IoT workloads. Data processing tasks and cron jobs

What are the strengths of Openfaas?

What are the limitations of Openfaas?

How can I practice Openfaas typing speed?

CodeSpeedTest offers 10+ real Openfaas code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.