Add an --app= flag for specifying the WSGI application

docs/runner.rst

@@ -20,6 +20,10 @@ Is equivalent to::
 
     waitress-serve --port=8041 --url-scheme=https myapp:wsgifunc
 
+Or:
+
+    waitress-serve --port=8041 --url-scheme=https --app=myapp:wsgifunc
+
 The full argument list is :ref:`given below <invocation>`.
 
 Boolean arguments are represented by flags. If you wish to explicitly set a
@@ -64,13 +68,19 @@ Invocation
 
 Usage::
 
-    waitress-serve [OPTS] MODULE:OBJECT
+    waitress-serve [OPTS] [MODULE:OBJECT]
 
 Common options:
 
 ``--help``
     Show this information.
 
+``--app=MODULE:OBJECT``
+    Run the given callable object the WSGI application.
+
+    You can specify the WSGI application using this flag or as a positional
+    argument.
+
 ``--call``
     Call the given object to get the WSGI application.
 

src/waitress/adjustments.py

@@ -459,9 +459,12 @@ def parse_args(cls, argv):
             else:
                 long_opts.append(opt + "=")
 
+        long_opts.append("app=")
+
         kw = {
             "help": False,
             "call": False,
+            "app": None,
         }
 
         opts, args = getopt.getopt(argv, "", long_opts)
@@ -477,11 +480,16 @@ def parse_args(cls, argv):
                 kw[param] = "false"
             elif param in ("help", "call"):
                 kw[param] = True
+            elif param == "app":
+                kw[param] = value
             elif cls._param_map[param] is asbool:
                 kw[param] = "true"
             else:
                 kw[param] = value
 
+        if kw["app"] is None and len(args) > 0:
+            kw["app"] = args.pop(0)
+
         return kw, args
 
     @classmethod

src/waitress/runner.py

@@ -29,13 +29,19 @@
 HELP = """\
 Usage:
 
-    {0} [OPTS] MODULE:OBJECT
+    {0} [OPTS] [MODULE:OBJECT]
 
 Standard options:
 
     --help
         Show this information.
 
+    --app=MODULE:OBJECT
+        Run the given callable object the WSGI application.
+
+        You can specify the WSGI application using this flag or as a positional
+        argument.
+
     --call
         Call the given object to get the WSGI application.
 
@@ -308,8 +314,8 @@ def run(argv=sys.argv, _serve=serve):
         show_help(sys.stdout, name)
         return 0
 
-    if len(args) != 1:
-        show_help(sys.stderr, name, "Specify one application only")
+    if kw["app"] is None:
+        show_help(sys.stderr, name, "Specify an application")
         return 1
 
     # set a default level for the logger only if it hasn't been set explicitly
@@ -323,7 +329,7 @@ def run(argv=sys.argv, _serve=serve):
 
     # Get the WSGI function.
     try:
-        app = pkgutil.resolve_name(args[0])
+        app = pkgutil.resolve_name(kw["app"])
     except (ValueError, ImportError, AttributeError) as exc:
         show_help(sys.stderr, name, str(exc))
         show_exception(sys.stderr)
@@ -332,7 +338,7 @@ def run(argv=sys.argv, _serve=serve):
         app = app()
 
     # These arguments are specific to the runner, not waitress itself.
-    del kw["call"], kw["help"]
+    del kw["call"], kw["help"], kw["app"]
 
     _serve(app, **kw)
     return 0

tests/test_adjustments.py

@@ -396,22 +396,32 @@ def assertDictContainsSubset(self, subset, dictionary):
 
     def test_noargs(self):
         opts, args = self.parse([])
-        self.assertDictEqual(opts, {"call": False, "help": False})
+        self.assertDictEqual(opts, {"call": False, "help": False, "app": None})
         self.assertSequenceEqual(args, [])
 
     def test_help(self):
         opts, args = self.parse(["--help"])
-        self.assertDictEqual(opts, {"call": False, "help": True})
+        self.assertDictEqual(opts, {"call": False, "help": True, "app": None})
         self.assertSequenceEqual(args, [])
 
     def test_call(self):
         opts, args = self.parse(["--call"])
-        self.assertDictEqual(opts, {"call": True, "help": False})
+        self.assertDictEqual(opts, {"call": True, "help": False, "app": None})
         self.assertSequenceEqual(args, [])
 
     def test_both(self):
         opts, args = self.parse(["--call", "--help"])
-        self.assertDictEqual(opts, {"call": True, "help": True})
+        self.assertDictEqual(opts, {"call": True, "help": True, "app": None})
+        self.assertSequenceEqual(args, [])
+
+    def test_app_flag(self):
+        opts, args = self.parse(["--app=fred:wilma", "barney:betty"])
+        self.assertEqual(opts["app"], "fred:wilma")
+        self.assertSequenceEqual(args, ["barney:betty"])
+
+    def test_app_arg(self):
+        opts, args = self.parse(["barney:betty"])
+        self.assertEqual(opts["app"], "barney:betty")
         self.assertSequenceEqual(args, [])
 
     def test_positive_boolean(self):

tests/test_runner.py

@@ -21,10 +21,10 @@ def test_help(self):
         self.match_output(["--help"], 0, "^Usage:\n\n    waitress-serve")
 
     def test_no_app(self):
-        self.match_output([], 1, "^Error: Specify one application only")
+        self.match_output([], 1, "^Error: Specify an application")
 
     def test_multiple_apps_app(self):
-        self.match_output(["a:a", "b:b"], 1, "^Error: Specify one application only")
+        self.match_output(["a:a", "b:b"], 1, "^Error: No module named 'a'")
 
     def test_bad_apps_app(self):
         self.match_output(["a"], 1, "^Error: No module named 'a'")