Function as a Service

Execute code on demand with automatic scaling and pay-per-execution billing.

Overview

Function as a Service (FaaS) eliminates infrastructure management. Write your function, configure it, and the platform handles scaling, routing, and availability. Ideal for microservices, APIs, event-based tasks, and background jobs.

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Prerequisites

• Dashboard or API access
• Code packaged (ZIP or container) or linked repository
• (Optional) Registry access for container deployments
• (Optional) CI/CD credentials for automated pipelines

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Supported Runtimes

Language	Versions
C#	6.0, 7.0
Java	11, 17, 21
Node.js	18, 19, 20
Python	3.8, 3.9, 3.10
Go	1.20, 1.21

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Step 1: Create Function

1. Navigate to Compute > Function as a Service
2. Click Create Function
3. Configure:

Setting	Description
Function name	e.g., processImage
Runtime	Select from supported versions
Entry point	Handler method (language-specific)
Code	Upload ZIP or link repository
Region	Deployment location

4. Click Create

Deployment takes seconds. Function is active when status shows Ready.

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Step 2: Configure Runtime

Setting	Description
Memory	128 MB, 256 MB, etc.
Timeout	Max execution duration (default 60s)
Environment Variables	Runtime config and secrets
Concurrency	Min/max instances (0 enables scale-to-zero)
Trigger	HTTP endpoint, event, or cron schedule

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Step 3: CI/CD with GitHub Actions

name: "Deploy Function as a Service"

on:
  push:
    branches: [ "main" ]

jobs:
  build-and-deploy:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v4

      - name: Setup runtime (if needed)
        uses: actions/setup-node@v5
        with:
          node-version: "18"

      - name: Build/package
        run: |
          zip -r function.zip .

      - name: Deploy function
        run: |
          curl -X POST https://api.platform.example.com/v1/faas/functions/deploy \
            -H "Authorization: Bearer ${{ secrets.FAAS_API_KEY }}" \
            -F "name=myfunction" \
            -F "runtime=nodejs18" \
            -F "file=@function.zip"

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Step 4: Invoke Function

HTTP Trigger

curl -X POST https://faas.example.net/functions/myfunction \
  -H "Authorization: Bearer <TOKEN>" \
  -d '{"key":"value"}'

Check logs to verify output. Scheduled or event triggers execute automatically.

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Step 5: Scaling and Optimization

• Scale-to-zero when no traffic, scale up on demand
• Monitor invocation count, duration, memory, error rate
• Optimize memory/time to minimize cost
• Set minimum instances to reduce cold-start latency

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Features Summary

Feature	Description
Multiple Runtimes	C#, Java, Node.js, Python, Go
Flexible Triggers	HTTP, events, cron schedules
Zero Infrastructure	No servers or clusters to manage
Auto-scaling	Scale up on demand, scale-to-zero
Secrets Handling	Secure runtime config injection
CI/CD Integration	Automated deployment pipelines
Pay-per-use	Charged only for execution time
Full Observability	Logging, metrics, monitoring

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Code Examples

Python

def handler(event, context):
    return "hello world"

Node.js

module.exports = {
  handler: function (event, context) {
    return 'hello world!';
  }
}

Go

package kubeless

func Handler(event map[string]interface{}, context map[string]string) (string, error) {
    return "Hello world!", nil
}

Java

public class Module {
    public String handler(Map event, Map context) {
        return "hello world";
    }
}

C#

using System;
using System.Collections.Generic;
using System.Threading.Tasks;

public class module
{
    public Task handler(Dictionary k8Event, Dictionary k8Context)
    {
        return Task.FromResult("hello world");
    }
}

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Troubleshooting

Issue	Cause	Solution
Stuck deploying	Invalid package or runtime	Check build logs, verify runtime
Invocation error	Bug or missing dependency	Test locally, review logs
High cold-start latency	No minimum instances	Set min instances > 0
Unsupported version	Runtime not available	Choose supported version
CI/CD failed	Invalid credentials	Verify API key and URL