`localstack/localstack:latest` will require auth token from March 23 — LocalStack module docs & examples need updating

[HarshCasper]

Hey folks 👋

I'm Harsh from the LocalStack team. Wanted to flag an upcoming change that will directly affect users of the LocalStack module in this library.

What's changing: Starting March 23, 2026, localstack/localstack:latest on Docker Hub will consolidate into a single unified image that requires authentication via a LOCALSTACK_AUTH_TOKEN. The free Community image, as it exists today, will no longer be available under that tag without an auth token set.

What this means for this repo:

testcontainers-scala wraps testcontainers-java, and the LocalStack module in modules/localstack pulls localstack/localstack by default to spin up the container during tests. Any user who instantiates LocalStackContainer after March 23 without a LOCALSTACK_AUTH_TOKEN set will hit an authentication error and their tests will fail immediately.

The places most likely to need updating:

• The LocalStack module in modules/localstack, where passing LOCALSTACK_AUTH_TOKEN as an environment variable should be documented or facilitated
• Any docs or examples referencing LocalStack usage that don't currently mention auth token setup as a prerequisite
• The CI/CD pipeline (.github/workflows/test.yml) if it runs LocalStack-based tests without an auth token

What users will need to do:

1. Sign up for a free LocalStack account at [localstack.cloud](https://localstack.cloud/)
2. Generate an auth token from the LocalStack Web App
3. Set LOCALSTACK_AUTH_TOKEN as an environment variable when starting the container

With testcontainers-scala, this would look like:

override val container: LocalStackContainer = LocalStackContainer(
  tag = "latest",
  services = Seq(Service.S3)
).configure(c =>
  c.withEnv("LOCALSTACK_AUTH_TOKEN", sys.env.getOrElse("LOCALSTACK_AUTH_TOKEN", ""))
)

The good news: A free tier is staying — no one has to pay. CI credits are now unlimited on all plans, including free, and open-source projects like this one can apply for free access to paid plans.

Full details in our announcements:

• https://blog.localstack.cloud/the-road-ahead-for-localstack/
• https://blog.localstack.cloud/localstack-single-image-next-steps/
• https://blog.localstack.cloud/2026-upcoming-pricing-changes/

Happy to help with any doc updates, review PRs, or answer questions. Let us know if there's anything we can do to make this easier — and thanks for maintaining the LocalStack module for the Scala community! 🙏

[vieiralucas]

If there's interest in offering an auth-free alternative alongside the LocalStack module, fakecloud could work. It runs on port 4566, ships as a Docker image (ghcr.io/faiscadev/fakecloud), and covers S3, SQS, SNS, DynamoDB, IAM, and other common services.

Happy to contribute a fakecloud module if that's something the project would want.

Disclosure: I'm the author of fakecloud.