Fix WireMockContainerBuilder (duplicate entries) (#1222)

src/WireMock.Net.Testcontainers/Utils/TestcontainersUtils.cs

@@ -0,0 +1,31 @@
+// Copyright © WireMock.Net
+
+using System;
+using System.Runtime.InteropServices;
+using DotNet.Testcontainers.Configurations;
+using System.Threading.Tasks;
+
+namespace WireMock.Net.Testcontainers.Utils;
+
+/// <summary>
+/// Some utility methods for containers.
+/// </summary>
+public static class TestcontainersUtils
+{
+    /// <summary>
+    /// Get the OS platform of the Docker image.
+    /// </summary>
+    public static Lazy<Task<OSPlatform>> GetImageOSAsync = new(async () =>
+    {
+        if (TestcontainersSettings.OS.DockerEndpointAuthConfig == null)
+        {
+            throw new InvalidOperationException($"The {nameof(TestcontainersSettings.OS.DockerEndpointAuthConfig)} is null. Check if Docker is started.");
+        }
+
+        using var dockerClientConfig = TestcontainersSettings.OS.DockerEndpointAuthConfig.GetDockerClientConfiguration();
+        using var dockerClient = dockerClientConfig.CreateClient();
+
+        var version = await dockerClient.System.GetVersionAsync();
+        return version.Os.IndexOf("Windows", StringComparison.OrdinalIgnoreCase) >= 0 ? OSPlatform.Windows : OSPlatform.Linux;
+    });
+}