Fix: Configuration providers provide current values

[vlaskal]

trafficstars

Configuration providers provide current value from environment variables or setting file. This is suggestion how to fix issue #576 to make test runnable nd independent on the order.

[vlaskal]

This solution will work even for this test modification for TLS:

[CollectionDefinition(nameof(DockerEndpointAuthenticationProviderTest), DisableParallelization = true)]
  [Collection(nameof(DockerEndpointAuthenticationProviderTest))]
  public sealed class DockerEndpointAuthenticationProviderTest
  {
    [Theory]
    [ClassData(typeof(AuthConfigTestData))]
    public void GetDockerClientConfiguration(IDockerEndpointAuthenticationConfiguration authConfig, Uri expectedDockerClientEndpoint)
    {
      using (var dockerClientConfiguration = authConfig.GetDockerClientConfiguration())
      {
        Assert.Equal(expectedDockerClientEndpoint, authConfig.Endpoint);
        Assert.Equal(expectedDockerClientEndpoint, dockerClientConfiguration.EndpointBaseUri);
      }
    }

    private sealed class AuthConfigTestData : List<object[]>
    {
      public AuthConfigTestData()
      {
        const string dockerHostVariableName = "DOCKER_HOST";
        const string dockerHost = "tcp://127.0.0.1:2375";
        const string dockerHostTls = "tcp://127.0.0.1:2376";

        var originalDockerHostvalue = Environment.GetEnvironmentVariable(dockerHostVariableName);

        Environment.SetEnvironmentVariable(dockerHostVariableName, dockerHostTls);
        this.Add(new object[] { new TlsEndpointAuthenticationProvider().GetAuthConfig(), new Uri(dockerHostTls) });

        Environment.SetEnvironmentVariable(dockerHostVariableName, dockerHost);
        this.Add(new object[] { new EnvironmentEndpointAuthenticationProvider().GetAuthConfig(), new Uri(dockerHost) });
        this.Add(new object[] { new NpipeEndpointAuthenticationProvider().GetAuthConfig(), new Uri("npipe://./pipe/docker_engine") });
        this.Add(new object[] { new UnixEndpointAuthenticationProvider().GetAuthConfig(), new Uri("unix:/var/run/docker.sock") });

        Environment.SetEnvironmentVariable(dockerHostVariableName, originalDockerHostvalue);
      }
    }
  }

[vlaskal]

I am not sure but this bug is about environment configuration problem and not about TLS. I think mixing environment configuration with settings files does not make sense to me. Maybe I am blind., but I thin that tls should not be as argument for EnvironmentEndpointAuthenticationProvider which should provide that value. I do not see solution for current situation.

[HofmeisterAn]

My example is poorly chosen - sorry. Forget about GetDockerTls(), etc. I meant to say that all you need is DI. The singleton makes the class difficult to test, DI solves that. My example above is showing the idea with different custom configurations.

An authentication provider depend on the custom configuration. Overload the constructor with ICustomConfiguration. The default constructor will fall back to the singleton instances. Your tests will use the overloaded constructor, specific with the custom configuration you need (very common pattern).

Overload the constructor with either params ICustomConfiguration[] customConfigurations or ICustomConfiguration propertiesFileConfiguration, ICustomConfiguration environmentConfiguration. For now, I personally prefer the first one, it is easier to set up in the tests. Does that help?

[vlaskal]

@HofmeisterAn Sorry for late answer. I will update it.

[vlaskal]

Fix was updated based on suggestion and covered by one mroe test.

[HofmeisterAn]

f0f112bd53cc4c1ff8dcbb2001334a1b36a9f487, closes #576.