wsgi: When encountering error in Python code, print traceback to logs.

Signed-off-by: Jelmer Vernooij <jelmer@samba.org>

diff --git a/source4/web_server/wsgi.c b/source4/web_server/wsgi.c
index 00c9535cac4388f85eb740e170d9d50fe93fd968..615726ad7ac2ea730f707b09afc8a56d1d417727 100644 (file)
--- a/source4/web_server/wsgi.c
+++ b/source4/web_server/wsgi.c
@@ -134,7 +134,7 @@ static PyObject *py_error_write(PyObject *self, PyObject *args, PyObject *kwargs
                return NULL;
        }
 
-       DEBUG(0, ("WSGI App: %s", str));
+       DEBUG(0, ("%s", str));
 
        Py_RETURN_NONE;
 }
@@ -147,11 +147,11 @@ static PyObject *py_error_writelines(PyObject *self, PyObject *args, PyObject *k
        if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O:writelines", discard_const_p(char *, kwnames), &seq)) {
                return NULL;
        }
-       
+
        while ((item = PyIter_Next(seq))) {
                char *str = PyString_AsString(item);
 
-               DEBUG(0, ("WSGI App: %s", str));
+               DEBUG(0, ("%s", str));
        }
 
        Py_RETURN_NONE;
@@ -260,6 +260,49 @@ static PyObject *Py_ErrorHttpStream(void)
        return (PyObject *)ret;
 }
 
+static void DEBUG_Print_PyError(int level, const char *message)
+{
+       PyObject *old_stderr, *new_stderr;
+       PyObject *sys_module;
+       PyObject *ptype, *pvalue, *ptb;
+
+       PyErr_Fetch(&ptype, &pvalue, &ptb);
+
+       DEBUG(0, ("WSGI: Server exception occurred: %s\n", message));
+
+       sys_module = PyImport_ImportModule("sys");
+       if (sys_module == NULL) {
+               DEBUG(0, ("Unable to obtain sys module while printing error"));
+               return;
+       }
+
+       old_stderr = PyObject_GetAttrString(sys_module, "stderr");
+       if (old_stderr == NULL) {
+               DEBUG(0, ("Unable to obtain old stderr"));
+               Py_DECREF(sys_module);
+               return;
+       }
+
+       new_stderr = Py_ErrorHttpStream();
+       if (new_stderr == NULL) {
+               DEBUG(0, ("Unable to create error stream"));
+               Py_DECREF(sys_module);
+               Py_DECREF(old_stderr);
+               return;
+       }
+
+       PyObject_SetAttrString(sys_module, "stderr", new_stderr);
+       Py_DECREF(new_stderr);
+
+       PyErr_Restore(ptype, pvalue, ptb);
+       PyErr_Print();
+
+       PyObject_SetAttrString(sys_module, "stderr", old_stderr);
+       Py_DECREF(old_stderr);
+
+       Py_DECREF(sys_module);
+}
+
 static PyObject *create_environ(bool tls, int content_length, struct http_header *headers, const char *request_method, const char *servername, int serverport, PyObject *inputstream, const char *request_string)
 {
        PyObject *env;
@@ -380,7 +423,7 @@ static void wsgi_process_http_input(struct web_server_data *wdata,
 
        py_web = PyObject_New(web_request_Object, &web_request_Type);
        if (py_web == NULL) {
-               DEBUG(0, ("Unable to allocate web request"));
+               DEBUG_Print_PyError(0, "Unable to allocate web request");
                return;
        }
        py_web->web = web;
@@ -392,7 +435,7 @@ static void wsgi_process_http_input(struct web_server_data *wdata,
 
        py_input_stream = Py_InputHttpStream(web);
        if (py_input_stream == NULL) {
-               DEBUG(0, ("unable to create python input stream"));
+               DEBUG_Print_PyError(0, "unable to create python input stream");
                return;
        }
 
@@ -409,7 +452,7 @@ static void wsgi_process_http_input(struct web_server_data *wdata,
        Py_DECREF(py_input_stream);
 
        if (py_environ == NULL) {
-               DEBUG(0, ("Unable to create WSGI environment object\n"));
+               DEBUG_Print_PyError(0, "Unable to create WSGI environment object");
                return;
        }
 
@@ -417,7 +460,7 @@ static void wsgi_process_http_input(struct web_server_data *wdata,
                                       py_environ, PyObject_GetAttrString((PyObject *)py_web, "start_response"));
 
        if (result == NULL) {
-               DEBUG(0, ("error while running WSGI code\n"));
+               DEBUG_Print_PyError(0, "error while handling request");
                return;
        }
 
@@ -425,7 +468,7 @@ static void wsgi_process_http_input(struct web_server_data *wdata,
        Py_DECREF(result);
 
        if (iter == NULL) {
-               DEBUG(0, ("wsgi application did not return iterable\n"));
+               DEBUG_Print_PyError(0, "application did not return iterable");
                return;
        }
 
@@ -460,7 +503,7 @@ bool wsgi_initialize(struct web_server_data *wdata)
        wdata->http_process_input = wsgi_process_http_input;
        py_web_server = PyImport_ImportModule("samba.web_server");
        if (py_web_server == NULL) {
-               DEBUG(0, ("Unable to find web server\n"));
+               DEBUG_Print_PyError(0, "Unable to find web server");
                return false;
        }
        wdata->private_data = py_web_server;