Problem to connect to LocalStack from dotnet container from another network

[mwilde]

Hi
I have the following setup:

• dot8 app with integration test (for playing around with S3) including LocalStack Testcontainer
• app is building inside AzureDevOps with pipeline.yaml
• the 'dotnet test' command runs inside a dotnet container with a different docker network
• Testcontainers 4.1.0
• Testcontainers.LocalStack 4.1.0

What I do:

My test setup spawns a LocalStack Testcontainer (usage of S3), than starts the application and does a simple 'try-it-out-test' (create bucket, upload some content and download the stuff again).

My LocalStack :

var localStackContainer = new LocalStackBuilder()
                                  .WithImage("localstack/localstack:s3-latest")
                                  .WithCleanUp(true)
                                  .WithEnvironment("GATEWAY_LISTEN", "0.0.0.0")
                                  .WithEnvironment("DEBUG", "1")
                                  .WithEnvironment("LS_LOG", "trace")
                                  .WithOutputConsumer(Consume.RedirectStdoutAndStderrToConsole())
                                  .WithWaitStrategy(
                                      Wait.ForUnixContainer()
                                          .AddCustomWaitStrategy(new UntilReady(), x => x.WithTimeout(TimeSpan.FromMinutes(1))))
                                  .Build();

private sealed class UntilReady : IWaitUntil
    {
        public async Task<bool> UntilAsync(IContainer container)
        {
            var (stdout, _) = await container.GetLogsAsync();
            return stdout != null && stdout.Contains("Ready.\n");
        }
    }

My pipeline job:

stages:
  - stage: test
    displayName: 'Test'
    jobs:
      - job:
        container: dotnet
        steps:
          - script: |
              dotnet test --logger "console;verbosity=detailed"
            displayName: 'Dotnet test'

My example aws step:

[Given("^there is a bucket$")]
    public async Task GivenThereIsABucket()
    {
        await using var scope  = cloudDriver.GetServiceScopeFactory.CreateAsyncScope();
        var             amazon = scope.ServiceProvider.GetRequiredService<IAmazonS3>();

        var putBucketResponse = await amazon.PutBucketAsync("my-bucket");
    }

What I want:

The app which is started inside an integration test inside the dotnet container should connect to LocalStack and do some playground stuff which I discribed above. As discribed in the docu https://docs.localstack.cloud/references/network-troubleshooting/endpoint-url/ the last scenario 'From a separate host' is matching to my environment and I used the env variable 'GATEWAY_LISTEN="0.0.0.0"' inside my configuration above.

What happens:

The LocalStack container is running, my app is running and when the code executes the first command (await amazon.PutBucketAsync("my-bucket")) fails with exception
AmazonS3Client 22|2024-12-18T19:25:36.488Z|ERROR|Received error response: [] --> Amazon.S3.AmazonS3Exception: Error making request with Error Code Forbidden and Http Status Code Forbidden. No further error information was returned by the service.

The ConnectionString from LocalStack looks like the following: 'http://172.27.0.1:33040' and is used as ServiceURL for the AWS client

What is the problem ?

• Wrong Testcontainer code setup ?
• The network created from dotnet container '/usr/bin/docker network create --label e6ee42 vsts_network_f2a031faa325455abf8b4fffbcb3b224' is different then LocalStack expects ?
• Wrong usage of GATEWAY_LISTEN ?
• Running the whole code on my local machine with Docker Desktop works fine

Log output from my Azure pipeline

log.txt

[mwilde]

Problem is solved.

In my setup on the build server, the AWS skd uses not my overgiven host (ip). Instead there is a fancy logic which maps my host "http://172.27.0.1:33040" to a DNS name in the following format "http://my-bucket.s3.localhost.localstack.cloud:4566/". So for that path there is no NO_PROXY rule and no network-alias defined. In fact that both containers are in different networks (LocalStack [default], dotnet [specific]), my client cannot connect to LocalStack with exception "Forbidden" but under the hood the message is "Not allowed to connect".

Following steps to solve the problem:

• move LocalStack into the same network as the dotnet container
• use network-alias --network-alias s3.localhost.localstack.cloud --network-alias my-bucket.s3.localhost.localstack.cloud in LocalStack
• set no_proxy=".localhost.localstack.cloud,$no_proxy" in the dotnet container
• use "http://s3.localhost.localstack.cloud:4566" for AWS:ServiceUrl