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AWS emulator

AWS emulator

super_linear

Comments (165)

  • CharlieDigital
    Skeptical of using because it's not clear whether this was just an exercise or a real product they are going to ship and maintain.Floci[0] has been great for me. Use the Testcontainers[1], too.Bonus: works for GCP and Azure, too (so far have only used in limited capacity, though).[0] https://floci.io/[1] https://testcontainers.com/modules/floci/
  • wg0
    Say whatever but without AI and agents, no one in AWS would have thought of building this given the huge amount of services they have. Humanly, possible but very very costly. Not saying has not happened before but fakecloud and localstack etc? That moat is gone.I am shocked TBH that this is the new normal. Agents writing code in one of the most difficult to use languages. And ugly as well TBH, it pokes into your eyes. Subjective I know but it is a horrible language for humans.
  • Waterluvian
    If I understand this correctly, it means I can point my entire CDK project to the emulator and test a `cdk deploy`?I'm curious just how realistic the "internal" behaviour is emulated. It's been a while (since I got my stack working and I just don't like touching it now...), but I recall it being a real pain that sometimes odd, sometimes inconsistent things happened with setup and teardown (even through Terraform), which led to long timeouts if you did things in the wrong (but seemingly valid) order.
  • morelandjs
    Fellow Amazonian here. Want to say that I’m grateful you built this and it has tremendous value if pulled off well and properly maintained.Agentic development is all about closing off a system as much possible, then mocking up or simulating any inputs or dependencies that cannot be closed off. At that point, you let Claude crawl over the system and do its thing.This inevitably runs into problems with infrastructure and any tools that help mock up those interfaces will be tremendously valuable. Thank you!
  • super_linear
  • schonfinkel
    What makes this any different than fakecloud?https://github.com/faiscadev/fakecloudI had a good time using its SDK inside my integration tests. I'll give a couple months before even moving to this because it's weird how similar both projects look like.EDIT: After checking AWS's project I'd say stay away from it, looks heavily vibe slopped.
  • OptionOfT
    I remember asking this to one of the evangelists when AWS first came out, how do I run this locally. This was during the times where we actually tried to get all the .NET and C/C++ docs locally.Now doing the math I feel old.
  • Shakahs
    AWS already models all their services with Smithy, the specification language they created. Their API clients are all generated from Smithy, and the emulator seems to have been built using the Smithy specs and comprehensive integration testing against the real APIs. Using the spec ensures they hit every variant and optional field of every endpoint, unlike Floci and Ministack that only implement the more commonly used ones.https://github.com/aws/api-models-awshttps://github.com/smithy-lang/smithy
  • chaz6
    The README.md states you need 100GB free disk space to build, and they do not provide binary releases. I hope that changes soon!
  • ppcdeveloper
    Thank the maker!! I was not having a good time with LocalStack, only an average time. Definitely have to try this out. I need the environment to survive a reboot.
  • papichulo4
    Thanks to Fable, I’d imagine :)I’ve been having it build local mock APIs for any service that exposes its OpenAPI spec. Works like a charm.
  • OJFord
    > How AWS Emulator keeps improving> AI agents keep the emulator up to date with AWS.Is pretty interesting! No more detail than that tease though.https://docs.aws.amazon.com/emulator/latest/userguide/what-i...
  • yevmiyeci
    im mostly on cloudflare and wrangler dev/miniflare already gives you local workers, d1, r2 etc, but its hand built. the “agents build it and verify against the real service” approach seems like the actual new thing here. wonder if cf does something similar
  • gateauxd
    Excited to see this develop and be a free replacement to localstack / similar providers.
  • anon
    undefined
  • paavohtl
    Looks like this was ~100% generated with Claude within the past month. Interestingly it still has a lot of occurrences of words that Opus used way too much pre 5.5, so maybe they're not using the latest models.https://github.com/search?q=repo%3Aaws%2Faws-emulator+load-b...https://github.com/search?q=repo%3Aaws%2Faws-emulator+%2Fno+...https://github.com/search?q=repo%3Aaws%2Faws-emulator+golden...
  • nodesocket
    Does this have pricing data? So you can see how much deployed resources cost?
  • gosen
    Do I need to get certified to use it?
  • stuff4ben
    Wonder if this could be considered a replacement for Ministack which itself was a vibe-code replacement of Localstack?
  • hollowturtle
    Wouldn't be better using agents for simplifying the mess some services like iam or cognito are?
  • jbmchuck
    AFAICT there isn't a quick way to reset state other than restarting the process - in other words it probably isn't a drop in replacement for https://github.com/getmoto/moto for running tons of tests where the state of the mocked AWS system needs to be reset after each test. Hopefully they will implement a quick reset functionality; multiple accounts and full org APIs emulation would be nice too.
  • asdfman123
    This is no doubt made possible by an agentic coding loop. If you have the right checks in place, it can be easy to emulate existing software.I was able to create a TV emulator at my work with a mostly independent agentic loop, because we have a lot of tests to examine a smart TVs APIs. The agents mostly just need to make the tests pass.
  • weitzj
    Regarding this distributed lock service ALF:Is AWS offering such a lock service for its costumers ? Multi regional?
  • anon
    undefined
  • tptacek
    The title for this story should be "aws-emulator, from AWS".
  • 4ndrewl
    " the engineer’s job is to give them room to work on their own and to build the specs, tests, and merge gates that decide when that work is correct."I mean that's a job, but in many orgs it's been done by (cheaper) non-engineers (business analysts, QA professionals) for decades. So what does an engineer do?
  • __natty__
    For me, what is interesting in this project is it's git history.
  • ChrisArchitect
  • st3fan
    29000 commits and no contributors
  • prescriptivist
    It's funny to read AI-generated documentation that is the result of a prompt instructing the LLM to be as terse and straightforward as reasonably possible. The agent was probably told to conform to ASD-STE100.It's better than a lot of AI-generated documentation, but it also comes across as a gruff LLM that it is annoyed that it has to write the documentation at all.
  • ggcr
    Will it be maintained? Or was it more of a toy-project for its large scale agentic blogpost? [0][0] https://www.aboutamazon.com/news/aws/how-autonomous-ai-agent...
  • forgotpwd16
    ~30K commits in 3w; quality software for sure. Is someone trying to get promotion by tokenmaxxing? Ironic or unlucky coincidence or competitor(s) misdirection, that, only 2w ago, Amazon published memo discouraging AI abuse?
  • sebmellen
    RIP LocalStack… can’t say I’d be unhappy to see it go though.
  • hbcdbff
    > its “things-that-do-not-work” folder holds the issues describing behaviors the agents found that do not yet match real AWS.Claudeslop snuck in at the very end
  • microflash
    > AWS Emulator is configured to collect and report usage data to AWS, to gain insight into how AWS Emulator is used. Telemetry is on by default.They can't help themselves, can they?I'll stick with Floci and Testcontainers.
  • InsidiousWombat
    Seems like the bunch of AI induced failures they had "paid off" in getting this done
  • toenail
    Mh, no transfer family service... I wonder what else is missing..
  • fschuett
    Can it emulate billing too, i.e. "rand().powf(rand()) % downtime"?
  • nunez
    annoying that it took AI happening for AWS to finally deliver on this though I'm glad they didironically localstack is solid enough to probably not need this for most things
  • BorisMelnik
    ok who's gonna build the GUI / web console on top of it?
  • dboreham
    After waiting for years for this kind of thing I ended up working around the issue by: using the real service. With Claude's help I have many projects now that test against live hosting providers using accounts maintained exclusively for testing. It ends up costing $50 or so a month in fees but well worthwhile for the assurance things really work.
  • swiftcoder
    I guess they didn't decide this was worth it till they needed it to train an LLM, huh? Not like everyone (inside and outside of AWS) has needed such a test harness for years...
  • tonymet
    A mere 20 years too late. Now it’s faster to have AI mock your APIs for you. AI has been a boon for test coverage.
  • andreadito
    Finally!
  • anon
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  • cxr
    No idea why there's so much of this lately, but there are way too many editorialized submission titles hitting the front page recently. Please stop doing this.<https://news.ycombinator.com/newsguidelines.html>
  • toasteddonut
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  • lukisk
    [flagged]
  • kadharmfn
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  • WithHighProb
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  • gvieira
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  • ath3nd
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  • varispeed
    Just a little bit more to keep you hooked. You should do your best to stay away from these parasites. Especially if they don't respect your country and your people by not paying the right amount of tax.
  • rfgplk
    [flagged]