| 1 | // WSLC-HelloWorld |
| 2 | // |
| 3 | // The simplest possible WSL Container SDK sample, written in C using the flat |
| 4 | // C API (wslcsdk.h). It starts a lightweight WSL container from a small Linux |
| 5 | // image and runs `echo` inside it, streaming the output back to the Windows |
| 6 | // console. |
| 7 | |
| 8 | #include <winsock2.h> |
| 9 | #include <windows.h> |
| 10 | #include <stdio.h> |
| 11 | #include <objbase.h> |
| 12 | #include "wslcsdk.h" |
| 13 | |
| 14 | #pragma comment(lib, "ole32.lib") |
| 15 | #pragma comment(lib, "wslcsdk.lib") |
| 16 | |
| 17 | static const char* IMAGE_NAME = "alpine:latest"; |
| 18 | |
| 19 | // Process exit is signalled here so wmain can wait for it. |
| 20 | static HANDLE g_exitEvent = NULL; |
| 21 | static INT32 g_exitCode = -1; |
| 22 | |
| 23 | static void PrintError(const wchar_t* context, HRESULT hr, PWSTR error) |
| 24 | { |
| 25 | fwprintf(stderr, L"[wslc] Error: %s (0x%08X)", context, hr); |
| 26 | if (error != NULL) |
| 27 | { |
| 28 | fwprintf(stderr, L": %s", error); |
| 29 | CoTaskMemFree(error); |
| 30 | } |
| 31 | fwprintf(stderr, L"\n"); |
| 32 | } |
| 33 | |
| 34 | // Forward container stdout/stderr straight to the Windows console. |
| 35 | static void CALLBACK OnStdIO(WslcProcessIOHandle ioHandle, const BYTE* data, uint32_t dataSize, PVOID context) |
| 36 | { |
| 37 | FILE* output = (ioHandle == WSLC_PROCESS_IO_HANDLE_STDOUT) ? stdout : stderr; |
| 38 | (void)context; |
| 39 | fprintf(output, "%.*s", (int)dataSize, (const char*)data); |
| 40 | fflush(output); |
| 41 | } |
| 42 | |
| 43 | // Record the exit code and wake up wmain. |
| 44 | static void CALLBACK OnProcessExit(INT32 exitCode, PVOID context) |
| 45 | { |
| 46 | (void)context; |
| 47 | g_exitCode = exitCode; |
| 48 | if (!SetEvent(g_exitEvent)) |
| 49 | { |
| 50 | fwprintf(stderr, L"[wslc] Warning: SetEvent failed (0x%08X)\n", GetLastError()); |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | // Build a storage path in a "WslcStorage" folder next to the executable, so the |
| 55 | // sample doesn't depend on any hard-coded absolute path. |
| 56 | static void GetStoragePath(wchar_t* buffer, size_t count) |
| 57 | { |
| 58 | wchar_t exePath[MAX_PATH]; |
| 59 | wchar_t* lastSlash; |
| 60 | GetModuleFileNameW(NULL, exePath, MAX_PATH); |
| 61 | lastSlash = wcsrchr(exePath, L'\\'); |
| 62 | if (lastSlash != NULL) |
| 63 | { |
| 64 | *(lastSlash + 1) = L'\0'; |
| 65 | } |
| 66 | swprintf(buffer, count, L"%sWslcStorage", exePath); |
| 67 | } |
| 68 | |
| 69 | int wmain(void) |
| 70 | { |
| 71 | HRESULT hr; |
| 72 | PWSTR error = NULL; |
| 73 | int result = 1; |
| 74 | |
| 75 | WslcSession session = NULL; |
| 76 | WslcContainer container = NULL; |
| 77 | WslcProcess process = NULL; |
| 78 | |
| 79 | WslcSessionSettings sessionSettings; |
| 80 | WslcContainerSettings containerSettings; |
| 81 | WslcProcessSettings initProcess; |
| 82 | WslcProcessSettings execProcess; |
| 83 | WslcProcessCallbacks callbacks; |
| 84 | WslcPullImageOptions pullOptions; |
| 85 | wchar_t storagePath[MAX_PATH]; |
| 86 | DWORD waitResult; |
| 87 | |
| 88 | PCSTR initArgv[2] = {"/bin/sleep", "60"}; |
| 89 | PCSTR echoArgv[2] = {"/bin/echo", "Hello, World from a WSL container!"}; |
| 90 | |
| 91 | hr = CoInitializeEx(NULL, COINIT_MULTITHREADED); |
| 92 | if (FAILED(hr)) |
| 93 | { |
| 94 | PrintError(L"Initialize COM", hr, NULL); |
| 95 | return 1; |
| 96 | } |
| 97 | |
| 98 | g_exitEvent = CreateEventW(NULL, TRUE, FALSE, NULL); |
| 99 | if (g_exitEvent == NULL) |
| 100 | { |
| 101 | PrintError(L"Create exit event", HRESULT_FROM_WIN32(GetLastError()), NULL); |
| 102 | goto cleanup; |
| 103 | } |
| 104 | |
| 105 | // ---- Session ---- |
| 106 | fwprintf(stderr, L"[wslc] Creating session...\n"); |
| 107 | GetStoragePath(storagePath, ARRAYSIZE(storagePath)); |
| 108 | hr = WslcInitSessionSettings(L"WSLCHelloWorld", storagePath, &sessionSettings); |
| 109 | if (FAILED(hr)) |
| 110 | { |
| 111 | PrintError(L"Init session settings", hr, NULL); |
| 112 | goto cleanup; |
| 113 | } |
| 114 | |
| 115 | hr = WslcCreateSession(&sessionSettings, &session, &error); |
| 116 | if (FAILED(hr)) |
| 117 | { |
| 118 | PrintError(L"Create session", hr, error); |
| 119 | goto cleanup; |
| 120 | } |
| 121 | |
| 122 | // ---- Pull image ---- |
| 123 | fwprintf(stderr, L"[wslc] Pulling image '%hs'...\n", IMAGE_NAME); |
| 124 | ZeroMemory(&pullOptions, sizeof(pullOptions)); |
| 125 | pullOptions.uri = IMAGE_NAME; |
| 126 | hr = WslcPullSessionImage(session, &pullOptions, &error); |
| 127 | if (FAILED(hr)) |
| 128 | { |
| 129 | PrintError(L"Pull image", hr, error); |
| 130 | goto cleanup; |
| 131 | } |
| 132 | |
| 133 | // ---- Create & start container ---- |
| 134 | fwprintf(stderr, L"[wslc] Starting container...\n"); |
| 135 | WslcInitProcessSettings(&initProcess); |
| 136 | WslcSetProcessSettingsCmdLine(&initProcess, initArgv, 2); |
| 137 | |
| 138 | WslcInitContainerSettings(IMAGE_NAME, &containerSettings); |
| 139 | WslcSetContainerSettingsName(&containerSettings, "wslc-helloworld"); |
| 140 | WslcSetContainerSettingsInitProcess(&containerSettings, &initProcess); |
| 141 | WslcSetContainerSettingsFlags(&containerSettings, WSLC_CONTAINER_FLAG_AUTO_REMOVE); |
| 142 | |
| 143 | hr = WslcCreateContainer(session, &containerSettings, &container, &error); |
| 144 | if (FAILED(hr)) |
| 145 | { |
| 146 | PrintError(L"Create container", hr, error); |
| 147 | goto cleanup; |
| 148 | } |
| 149 | |
| 150 | hr = WslcStartContainer(container, WSLC_CONTAINER_START_FLAG_NONE, &error); |
| 151 | if (FAILED(hr)) |
| 152 | { |
| 153 | PrintError(L"Start container", hr, error); |
| 154 | goto cleanup; |
| 155 | } |
| 156 | |
| 157 | // ---- Run echo ---- |
| 158 | fwprintf(stderr, L"[wslc] Running echo...\n"); |
| 159 | WslcInitProcessSettings(&execProcess); |
| 160 | WslcSetProcessSettingsCmdLine(&execProcess, echoArgv, 2); |
| 161 | |
| 162 | ZeroMemory(&callbacks, sizeof(callbacks)); |
| 163 | callbacks.onStdOut = OnStdIO; |
| 164 | callbacks.onStdErr = OnStdIO; |
| 165 | callbacks.onExit = OnProcessExit; |
| 166 | WslcSetProcessSettingsCallbacks(&execProcess, &callbacks, NULL); |
| 167 | |
| 168 | hr = WslcCreateContainerProcess(container, &execProcess, &process, &error); |
| 169 | if (FAILED(hr)) |
| 170 | { |
| 171 | PrintError(L"Run echo", hr, error); |
| 172 | goto cleanup; |
| 173 | } |
| 174 | |
| 175 | waitResult = WaitForSingleObject(g_exitEvent, 30000); |
| 176 | if (waitResult == WAIT_OBJECT_0) |
| 177 | { |
| 178 | result = g_exitCode; |
| 179 | } |
| 180 | else if (waitResult == WAIT_TIMEOUT) |
| 181 | { |
| 182 | fwprintf(stderr, L"[wslc] Error: Timed out waiting for the process to exit.\n"); |
| 183 | } |
| 184 | else |
| 185 | { |
| 186 | PrintError(L"Wait for process exit", HRESULT_FROM_WIN32(GetLastError()), NULL); |
| 187 | } |
| 188 | |
| 189 | cleanup: |
| 190 | fwprintf(stderr, L"[wslc] Shutting down...\n"); |
| 191 | |
| 192 | if (process != NULL) |
| 193 | { |
| 194 | WslcReleaseProcess(process); |
| 195 | } |
| 196 | if (g_exitEvent != NULL) |
| 197 | { |
| 198 | CloseHandle(g_exitEvent); |
| 199 | } |
| 200 | if (container != NULL) |
| 201 | { |
| 202 | WslcStopContainer(container, WSLC_SIGNAL_SIGTERM, 5, NULL); |
| 203 | WslcReleaseContainer(container); |
| 204 | } |
| 205 | if (session != NULL) |
| 206 | { |
| 207 | WslcTerminateSession(session); |
| 208 | WslcReleaseSession(session); |
| 209 | } |
| 210 | |
| 211 | fwprintf(stderr, L"[wslc] Done.\n"); |
| 212 | CoUninitialize(); |
| 213 | return result; |
| 214 | } |