this post was submitted on 27 Jun 2026
102 points (87.5% liked)

Programming

27640 readers
196 users here now

Welcome to the main community in programming.dev! Feel free to post anything relating to programming here!

Cross posting is strongly encouraged in the instance. If you feel your post or another person's post makes sense in another community cross post into it.

Hope you enjoy the instance!

Rules

Rules

  • Follow the programming.dev instance rules
  • Keep content related to programming in some way
  • If you're posting long videos try to add in some form of tldr for those who don't want to watch videos

Wormhole

Follow the wormhole through a path of communities !webdev@programming.dev

founded 3 years ago
MODERATORS
snowe@programming.dev
Ategon@programming.dev
UlrikHD@programming.dev
bugsmith@programming.dev
Spyro@programming.dev
102
LocalEmu, a free, open-source AWS emulator: run 132 AWS services locally with one pip install (localemu.cloud)
submitted 1 week ago by nullroute@programming.dev to c/programming@programming.dev
39 comments fedilink hide all child comments
 

I maintain LocalEmu, a free and open-source (Apache 2.0) AWS emulator. It started as a fork of the archived LocalStack Community edition. The goal is to keep a genuinely free, open local AWS emulator alive and maintained.

What it does:

  • Emulates 132 AWS services on a single endpoint (localhost:4566)
  • Pure-Python core, with real Docker engines for Lambda, EC2, RDS, ECS, EKS, and OpenSearch
  • Point your existing AWS CLI, boto3, Terraform, CDK, or Pulumi at it, zero config
  • No account, no auth token, no telemetry. Persistent state across restarts
  • Optional fidelity knobs: IAM policy enforcement, throttling, latency injection, Lambda cold starts

Why I built it: kill the multi-minute deploy loop, drop the dev/test AWS bill to zero, and stop keeping real credentials on dev machines.

It's for fast local dev, testing, and learning, not production, and not bit-for-bit parity with the real cloud.

Repo: https://github.com/localemu/localemu Site: https://localemu.cloud/

Happy to answer questions, and feedback is very welcome.

you are viewing a single comment's thread
view the rest of the comments
[โ€“] jtrek@startrek.website 5 points 1 week ago (1 children)

Interesting. We used the free localstack at a previous job and it kind of sucked. Mostly we were trying to do S3, and it made adding a lot of files kind of painful. Looks like this has better support for "I need to load a bunch of files into S3 when I start working".

Can you map a directory and subfolders to S3 with this, or so you need to make calls to "upload" everything?

[โ€“] nullroute@programming.dev 2 points 1 week ago

Thanks for trying LocalEmu :). Yes, you can map a directory without scripting per-file uploads.

aws s3 sync ./mydir s3://mybucket/ works against LocalEmu out of the box (or awsemu s3 sync with the bundled zero-config CLI). For "always populated on start", drop a one-line script in /etc/localemu/init/ready.d/ and it runs on every boot:

docker run --rm -d -p 4566:4566 \
  -v $PWD/fixtures:/fixtures:ro \
  -v $PWD/init:/etc/localemu/init/ready.d:ro \
  -e DASHBOARD_API_OPEN=1 localemu/localemu

Where init/ready.d/seed.sh does awsemu s3 sync /fixtures s3://mybucket/. Or PERSISTENCE=1 if you'd rather load once and have it stick.

LocalStack inspired a lot of this, we're the free open-source continuation.