ListContainersAsync response contains inconsistent public host ports

[HofmeisterAn]

Output of dotnet --info:

.NET SDK (reflecting any global.json):
 Version:   6.0.300
 Commit:    8473146e7d

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.19044
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\6.0.300\

Host (useful for support):
  Version: 6.0.5
  Commit:  70ae3df4a6

.NET SDKs installed:
  6.0.300 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs:
  https://aka.ms/dotnet-download

What version of Docker.DotNet?:

3.125.5

Steps to reproduce the issue:

public sealed class ExampleContainer
{
  private static readonly IDockerClient DockerClient = new DockerClientConfiguration(new Uri("npipe://./pipe/docker_engine")).CreateClient();

  private static readonly CreateContainerParameters CreateContainerParameters = new CreateContainerParameters();

  private readonly ISet<string> hostPorts = new HashSet<string>();

  private int tryCount;

  private string ID;

  static ExampleContainer()
  {
    var hostConfig = new HostConfig();
    hostConfig.PortBindings = new Dictionary<string, IList<PortBinding>> { { "80/tcp", GetFailureConfig() } };
    CreateContainerParameters.Image = "nginx";
    CreateContainerParameters.HostConfig = hostConfig;
  }

  [Fact]
  public Task ShouldReturnOnePublicHostPort()
  {
    return Task.WhenAll(Enumerable.Range(0, 25)
      .Select(_ => new ExampleContainer())
      .Select(example => Task.Run(async () =>
      {
        try
        {
          await example.InitializeAsync()
            .ConfigureAwait(false);
          await example.GetPublicHostPort()
            .ConfigureAwait(false);
        }
        finally
        {
          await example.DisposeAsync()
            .ConfigureAwait(false);
        }
      })));
  }

  private static IList<PortBinding> GetSuccessConfig()
  {
    return new[] { new PortBinding { HostPort = "0" } };
  }

  private static IList<PortBinding> GetFailureConfig()
  {
    return new[] { new PortBinding { HostPort = null } };
  }

  private async Task InitializeAsync()
  {
    var createContainerResponse = await DockerClient.Containers.CreateContainerAsync(CreateContainerParameters)
      .ConfigureAwait(false);
    this.ID = createContainerResponse.ID;

    _ = await DockerClient.Containers.StartContainerAsync(this.ID, new ContainerStartParameters())
      .ConfigureAwait(false);
  }

  private Task DisposeAsync()
  {
    var containerRemoveParameters = new ContainerRemoveParameters();
    containerRemoveParameters.Force = true;
    return DockerClient.Containers.RemoveContainerAsync(this.ID, containerRemoveParameters);
  }

  private async Task GetPublicHostPort()
  {
    do
    {
      var containersListParameters = new ContainersListParameters();
      containersListParameters.All = true;
      containersListParameters.Filters = new Dictionary<string, IDictionary<string, bool>>();
      containersListParameters.Filters.Add("id", new Dictionary<string, bool> { { this.ID, true } });

      var listContainersResponse = await DockerClient.Containers.ListContainersAsync(containersListParameters)
        .ConfigureAwait(false);

      foreach (var publicHostPort in listContainersResponse.Single().Ports.Select(portBindings => portBindings.PublicPort))
      {
        this.hostPorts.Add(publicHostPort.ToString(CultureInfo.InvariantCulture));
      }

      if (this.hostPorts.Count > 1)
      {
        throw new InvalidOperationException(string.Join(',', this.hostPorts));
      }
    }
    while (++this.tryCount < 10);
  }
}

What actually happened?:

The response of ListContainersAsync sometimes contains for a single port binding multiple public host ports. In this case, a service behind the mapped port is not available. It looks like setting the port binding host port to null (assign random port) breaks it. I attached a reproducible example above. E.g. L:89 throws: System.InvalidOperationException: 49196,52481.

• ... new[] { new PortBinding { HostPort = null } }: fails
• ... new[] { new PortBinding { HostPort = "0" } }: successful

This also breaks InspectContainerAsync. In this case the response (list of port bindings) is empty for at least the first call.

What did you expect to happen?:

A consistent response.

Additional information:

-

[HofmeisterAn]

Probably relates to #511.