Fix port conflict error message and cleanup on failure

src/windows/wslc/services/ContainerService.cpp

@@ -287,14 +287,16 @@ int ContainerService::Run(Session& session, const std::string& image, ContainerO
 {
     // Create the container
     auto runningContainer = CreateInternal(session, image, runOptions);
-    runningContainer.SetDeleteOnClose(false);
     auto& container = runningContainer.Get();
 
     // Start the created container
     WSLCContainerStartFlags startFlags{};
     WI_SetFlagIf(startFlags, WSLCContainerStartFlagsAttach, !runOptions.Detach);
     THROW_IF_FAILED(container.Start(startFlags, nullptr)); // TODO: Error message, detach keys
 
+    // Disable auto-delete only after successful start
+    runningContainer.SetDeleteOnClose(false);
+
     // Handle attach if requested
     if (WI_IsFlagSet(startFlags, WSLCContainerStartFlagsAttach))
     {

src/windows/wslcsession/WSLCContainer.cpp

@@ -1274,12 +1274,10 @@ std::unique_ptr<WSLCContainerImpl> WSLCContainerImpl::Open(
         {
             auto allocation = virtualMachine.TryAllocatePort(e.VmPort, e.Family, e.Protocol);
 
-            THROW_HR_IF_MSG(
+            THROW_HR_WITH_USER_ERROR_IF(
                 HRESULT_FROM_WIN32(ERROR_ALREADY_EXISTS),
-                !allocation,
-                "Port %hu is in use, cannot open container %hs",
-                e.VmPort,
-                dockerContainer.Id.c_str());
+                std::format(L"Port {} is already in use, cannot open container {}", e.VmPort, dockerContainer.Id),
+                !allocation);
 
             inserted.VmMapping.AssignVmPort(allocation);
         }
@@ -1443,20 +1441,31 @@ void WSLCContainerImpl::MapPorts()
                 auto allocatedPort =
                     m_virtualMachine.TryAllocatePort(e.ContainerPort, e.VmMapping.BindAddress.si_family, e.VmMapping.Protocol);
 
-                THROW_HR_IF_MSG(
+                THROW_HR_WITH_USER_ERROR_IF(
                     HRESULT_FROM_WIN32(ERROR_ALREADY_EXISTS),
-                    !allocatedPort,
-                    "Port %hu is in use, cannot start container %hs",
-                    e.ContainerPort,
-                    m_id.c_str());
+                    std::format(L"Port {} is already in use, cannot start container {}", e.VmMapping.HostPort(), m_id),
+                    !allocatedPort);
 
                 e.VmMapping.AssignVmPort(allocatedPort);
 
                 allocatedPorts.emplace(e.ContainerPort, allocatedPort);
             }
         }
 
-        m_virtualMachine.MapPort(e.VmMapping);
+        try
+        {
+            m_virtualMachine.MapPort(e.VmMapping);
+        }
+        catch (const wil::ResultException& ex)
+        {
+            if (ex.GetErrorCode() == HRESULT_FROM_WIN32(ERROR_ALREADY_EXISTS) || ex.GetErrorCode() == HRESULT_FROM_WIN32(WSAEADDRINUSE))
+            {
+                THROW_HR_WITH_USER_ERROR(
+                    HRESULT_FROM_WIN32(ERROR_ALREADY_EXISTS),
+                    std::format(L"Port {} is already in use, cannot start container {}", e.VmMapping.HostPort(), m_id));
+            }
+            throw;
+        }
     }
 }
 

test/windows/wslc/e2e/WSLCE2EContainerCreateTests.cpp

@@ -988,8 +988,6 @@ class WSLCE2EContainerCreateTests
     TEST_METHOD(WSLCE2E_Container_Run_PortAlreadyInUse)
     {
         // Bug: https://github.com/microsoft/WSL/issues/14448
-        SKIP_TEST_NOT_IMPL();
-
         WSL2_TEST_ONLY();
 
         // Start a container with a simple server listening on a port
@@ -1005,6 +1003,7 @@ class WSLCE2EContainerCreateTests
         // Attempt to start another container mapping the same host port
         auto result2 = RunWslc(std::format(L"container run -p {}:{} {}", HostTestPort1, ContainerTestPort, DebianImage.NameAndTag()));
         result2.Verify({.ExitCode = 1});
+        VERIFY_IS_TRUE(result2.Stderr.has_value() && result2.Stderr.value().find(L"is already in use") != std::wstring::npos);
     }
 
     // https://github.com/microsoft/WSL/issues/14433