Python: multiple values in the "path" option.

docs/changes.xml

@@ -9,6 +9,12 @@
          date="" time=""
          packager="Andrei Belov <defan@nginx.com>">
 
+<change type="feature">
+<para>
+ability to specify multiple directories in the "path" option of Python apps.
+</para>
+</change>
+
 <change type="bugfix">
 <para>
 invalid HTTP responses were generated for some unusual status codes.

src/nxt_application.h

@@ -47,13 +47,13 @@ typedef struct {
 
 
 typedef struct {
-    char       *home;
+    char                       *home;
-    nxt_str_t  path;
+    nxt_conf_value_t           *path;
-    nxt_str_t  module;
+    nxt_str_t                  module;
-    char       *callable;
+    char                       *callable;
-    nxt_str_t  protocol;
+    nxt_str_t                  protocol;
-    uint32_t   threads;
+    uint32_t                   threads;
-    uint32_t   thread_stack_size;
+    uint32_t                   thread_stack_size;
 } nxt_python_app_conf_t;
 
 

src/nxt_conf_validation.c

@@ -96,6 +96,10 @@ static nxt_int_t nxt_conf_vldt_return(nxt_conf_validation_t *vldt,
     nxt_conf_value_t *value, void *data);
 static nxt_int_t nxt_conf_vldt_proxy(nxt_conf_validation_t *vldt,
     nxt_conf_value_t *value, void *data);
+static nxt_int_t nxt_conf_vldt_python_path(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value, void *data);
+static nxt_int_t nxt_conf_vldt_python_path_element(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value);
 static nxt_int_t nxt_conf_vldt_python_protocol(nxt_conf_validation_t *vldt,
     nxt_conf_value_t *value, void *data);
 static nxt_int_t nxt_conf_vldt_threads(nxt_conf_validation_t *vldt,
@@ -491,7 +495,8 @@ static nxt_conf_vldt_object_t  nxt_conf_vldt_python_members[] = {
         .type       = NXT_CONF_VLDT_STRING,
     }, {
         .name       = nxt_string("path"),
-        .type       = NXT_CONF_VLDT_STRING,
+        .type       = NXT_CONF_VLDT_STRING | NXT_CONF_VLDT_ARRAY,
+        .validator  = nxt_conf_vldt_python_path,
     }, {
         .name       = nxt_string("module"),
         .type       = NXT_CONF_VLDT_STRING,
@@ -1376,6 +1381,34 @@ nxt_conf_vldt_proxy(nxt_conf_validation_t *vldt, nxt_conf_value_t *value,
 }
 
 
+static nxt_int_t
+nxt_conf_vldt_python_path(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value, void *data)
+{
+    if (nxt_conf_type(value) == NXT_CONF_ARRAY) {
+        return nxt_conf_vldt_array_iterator(vldt, value,
+                                            &nxt_conf_vldt_python_path_element);
+    }
+
+    /* NXT_CONF_STRING */
+
+    return NXT_OK;
+}
+
+
+static nxt_int_t
+nxt_conf_vldt_python_path_element(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value)
+{
+    if (nxt_conf_type(value) != NXT_CONF_STRING) {
+        return nxt_conf_vldt_error(vldt, "The \"path\" array must contain "
+                                   "only string values.");
+    }
+
+    return NXT_OK;
+}
+
+
 static nxt_int_t
 nxt_conf_vldt_python_protocol(nxt_conf_validation_t *vldt,
     nxt_conf_value_t *value, void *data)

src/nxt_main_process.c

@@ -182,7 +182,7 @@ static nxt_conf_map_t  nxt_python_app_conf[] = {
 
     {
         nxt_string("path"),
-        NXT_CONF_MAP_STR,
+        NXT_CONF_MAP_PTR,
         offsetof(nxt_common_app_conf_t, u.python.path),
     },
 

src/python/nxt_python.c

@@ -24,6 +24,7 @@ typedef struct {
 
 static nxt_int_t nxt_python_start(nxt_task_t *task,
     nxt_process_data_t *data);
+static nxt_int_t nxt_python_set_path(nxt_task_t *task, nxt_conf_value_t *value);
 static int nxt_python_init_threads(nxt_python_app_conf_t *c);
 static int nxt_python_ready_handler(nxt_unit_ctx_t *ctx);
 static void *nxt_python_thread_func(void *main_ctx);
@@ -67,7 +68,7 @@ nxt_python_start(nxt_task_t *task, nxt_process_data_t *data)
     int                    rc;
     char                   *nxt_py_module;
     size_t                 len;
-    PyObject               *obj, *pypath, *module;
+    PyObject               *obj, *module;
     nxt_str_t              proto;
     const char             *callable;
     nxt_unit_ctx_t         *unit_ctx;
@@ -162,38 +163,18 @@ nxt_python_start(nxt_task_t *task, nxt_process_data_t *data)
     }
 
     nxt_py_stderr_flush = PyObject_GetAttrString(obj, "flush");
+
+    /* obj is a Borrowed reference. */
+    obj = NULL;
+
     if (nxt_slow_path(nxt_py_stderr_flush == NULL)) {
         nxt_alert(task, "Python failed to get \"flush\" attribute of "
                         "\"sys.stderr\" object");
         goto fail;
     }
 
-    /* obj is a Borrowed reference. */
+    if (nxt_slow_path(nxt_python_set_path(task, c->path) != NXT_OK)) {
-
+        goto fail;
-    if (c->path.length > 0) {
-        obj = PyString_FromStringAndSize((char *) c->path.start,
-                                         c->path.length);
-
-        if (nxt_slow_path(obj == NULL)) {
-            nxt_alert(task, "Python failed to create string object \"%V\"",
-                      &c->path);
-            goto fail;
-        }
-
-        pypath = PySys_GetObject((char *) "path");
-
-        if (nxt_slow_path(pypath == NULL)) {
-            nxt_alert(task, "Python failed to get \"sys.path\" list");
-            goto fail;
-        }
-
-        if (nxt_slow_path(PyList_Insert(pypath, 0, obj) != 0)) {
-            nxt_alert(task, "Python failed to insert \"%V\" into \"sys.path\"",
-                      &c->path);
-            goto fail;
-        }
-
-        Py_DECREF(obj);
     }
 
     obj = Py_BuildValue("[s]", "unit");
@@ -317,6 +298,74 @@ fail:
 }
 
 
+static nxt_int_t
+nxt_python_set_path(nxt_task_t *task, nxt_conf_value_t *value)
+{
+    int               ret;
+    PyObject          *path, *sys;
+    nxt_str_t         str;
+    nxt_uint_t        n;
+    nxt_conf_value_t  *array;
+
+    if (value == NULL) {
+        return NXT_OK;
+    }
+
+    sys = PySys_GetObject((char *) "path");
+    if (nxt_slow_path(sys == NULL)) {
+        nxt_alert(task, "Python failed to get \"sys.path\" list");
+        return NXT_ERROR;
+    }
+
+    /* sys is a Borrowed reference. */
+
+    if (nxt_conf_type(value) == NXT_CONF_STRING) {
+        n = 0;
+        goto value_is_string;
+    }
+
+    /* NXT_CONF_ARRAY */
+    array = value;
+
+    n = nxt_conf_array_elements_count(array);
+
+    while (n != 0) {
+        n--;
+
+        /*
+         * Insertion in front of existing paths starting from the last element
+         * to preserve original order while giving priority to the values
+         * specified in the "path" option.
+         */
+
+        value = nxt_conf_get_array_element(array, n);
+
+    value_is_string:
+
+        nxt_conf_get_string(value, &str);
+
+        path = PyString_FromStringAndSize((char *) str.start, str.length);
+        if (nxt_slow_path(path == NULL)) {
+            nxt_alert(task, "Python failed to create string object \"%V\"",
+                      &str);
+            return NXT_ERROR;
+        }
+
+        ret = PyList_Insert(sys, 0, path);
+
+        Py_DECREF(path);
+
+        if (nxt_slow_path(ret != 0)) {
+            nxt_alert(task, "Python failed to insert \"%V\" into \"sys.path\"",
+                      &str);
+            return NXT_ERROR;
+        }
+    }
+
+    return NXT_OK;
+}
+
+
 static int
 nxt_python_init_threads(nxt_python_app_conf_t *c)
 {