Introducing cloudemu

Zero-cost in-memory cloud emulation for Go


Introducing cloudemu


We're excited to announce **cloudemu** — a Go library that emulates AWS, Azure, and GCP cloud services entirely in memory.


The Problem


Every team that builds on cloud services faces the same testing dilemma:


1. **Use real cloud accounts** — expensive, slow, requires network access

2. **Use Docker-based emulators** — complex setup, moderate speed, heavy on resources

3. **Write custom mocks** — tedious, incomplete, hard to maintain


None of these options give you fast, realistic, and free cloud testing.


The Solution


cloudemu provides 48 in-memory service implementations (16 categories across AWS, Azure, and GCP) that behave like the real thing:


aws := cloudemu.NewAWS()


// This works exactly like real EC2

instances, _ := aws.EC2.RunInstances(ctx, config, 3)


No cloud accounts. No Docker. No network calls. Tests run in ~10ms.


What Makes It Different


cloudemu goes beyond basic CRUD mocks:


  • **State machines** enforce valid lifecycle transitions
  • **Auto-metrics** are emitted to the monitoring service
  • **FIFO deduplication** with 5-minute windows
  • **Dead-letter queues** for messages exceeding max receive count
  • **TTL expiry** with lazy cleanup on read
  • **IAM policy evaluation** with wildcard matching

    • Get Started


    go get github.com/stackshy/cloudemu


    Check out the [Quick Start guide](/docs/quick-start) to build your first cloud simulation in 5 minutes.