Fix p* scripts to produce an error when given a bad config_uri

.github/workflows/ci-tests.yml

@@ -24,7 +24,7 @@ jobs:
                 os:
                     - "ubuntu-20.04"
                     - "windows-2022"
-                    - "macos-11"
+                    - "macos-12"
                 architecture:
                     - x64
                     - x86
@@ -41,7 +41,7 @@ jobs:
                     # Linux and macOS don't have x86 python
                     - os: "ubuntu-20.04"
                       architecture: x86
-                    - os: "macos-11"
+                    - os: "macos-12"
                       architecture: x86
 
         name: "Python: ${{ matrix.py }}-${{ matrix.architecture }} on ${{ matrix.os }}"

CHANGES.rst

@@ -52,6 +52,14 @@ Bug Fixes
 
   See https://github.com/Pylons/pyramid/pull/3742
 
+- When a bad settings URI (usually a path to a non-existant file) is
+  supplied to one of pyramid's command line programs, and in general
+  when there is a reason why a settings file cannot be used, produce
+  an error message instead of a traceback.
+
+  Applications which import pyramid.paster must handle the
+  plaster.exceptions.PlasterError exception themselves.
+
 Backward Incompatibilities
 --------------------------
 

docs/narr/commandline.rst

@@ -715,7 +715,16 @@ your application and tries to run it, there just is no request data, because
 there isn't any real web request.  Therefore some parts of your application and
 some Pyramid APIs will not work.
 
-For this reason, :app:`Pyramid` makes it possible to run a script in an
+To assist with script writing :app:`Pyramid` provides the
+:mod:`paster <pyramid.paster>` module.
+
+.. versionchanged:: 2.0
+   Users of :mod:`paster <pyramid.paster>` are expected to themselves
+   handle any exceptions that might be raised by the :term:`plaster`
+   library, reporting to the user any problems (non-existant files,
+   etc.) with obtaining settings.
+
+:app:`Pyramid` makes it possible to run a script in an
 environment much like the environment produced when a particular
 :term:`request` reaches your :app:`Pyramid` application.  This is achieved by
 using the :func:`pyramid.paster.bootstrap` command in the body of your script.

src/pyramid/scripts/common.py

@@ -1,4 +1,6 @@
 import plaster
+import plaster.exceptions
+import sys
 
 
 def parse_vars(args):
@@ -15,9 +17,23 @@ def parse_vars(args):
     return result
 
 
-def get_config_loader(config_uri):
-    """
-    Find a ``plaster.ILoader`` object supporting the "wsgi" protocol.
+def get_config_loader(config_uri, report_failure=None):
+    """Find a ``plaster.ILoader`` object supporting the "wsgi" protocol.
+
+    ``report_failure``, if passed, must be a function of one argument,
+    a string.  The function is called with an error message when the
+    ``config_uri`` cannot be used to obtain settings.  After
+    ``report_failure`` is called the program exits with a ``1``
+    (failure) status code.
+
+    When ``report_failure`` is not passed, or is None, the caller is expected
+    to handle PlasterError exceptions raised by :term:`plaster`.
 
     """
-    return plaster.get_loader(config_uri, protocols=['wsgi'])
+    try:
+        return plaster.get_loader(config_uri, protocols=['wsgi'])
+    except plaster.exceptions.PlasterError as e:
+        if not report_failure:
+            raise e
+        report_failure(f'The settings given are not available: {e}')
+        sys.exit(1)

src/pyramid/scripts/prequest.py

@@ -140,7 +140,7 @@ def run(self):
         config_vars.setdefault('__script__', self.script_name)
         path = self.args.path_info
 
-        loader = self._get_config_loader(config_uri)
+        loader = self._get_config_loader(config_uri, self.out)
         loader.setup_logging(config_vars)
 
         app = loader.get_wsgi_app(self.args.app_name, config_vars)

src/pyramid/scripts/proutes.py

@@ -318,7 +318,7 @@ def run(self, quiet=False):
         config_uri = self.args.config_uri
         config_vars = parse_vars(self.args.config_vars)
         config_vars.setdefault('__script__', self.script_name)
-        loader = self.get_config_loader(config_uri)
+        loader = self.get_config_loader(config_uri, self.out)
         loader.setup_logging(config_vars)
         self.proutes_file_config(loader, config_vars)
 

src/pyramid/scripts/pserve.py

@@ -187,7 +187,7 @@ def run(self):  # pragma: no cover
         app_spec = self.args.config_uri
         app_name = self.args.app_name
 
-        loader = self._get_config_loader(config_uri)
+        loader = self._get_config_loader(config_uri, self.out)
 
         # setup logging only in the worker process incase the logging config
         # opens files which should not be opened by multiple processes at once

src/pyramid/scripts/pshell.py

@@ -132,7 +132,7 @@ def run(self, shell=None):
         config_uri = self.args.config_uri
         config_vars = parse_vars(self.args.config_vars)
         config_vars.setdefault('__script__', self.script_name)
-        loader = self.get_config_loader(config_uri)
+        loader = self.get_config_loader(config_uri, self.out)
         loader.setup_logging(config_vars)
         self.pshell_file_config(loader, config_vars)
 

tests/test_scripts/dummy.py

@@ -174,7 +174,7 @@ def __init__(
         self.server = server
         self.calls = []
 
-    def __call__(self, uri):
+    def __call__(self, uri, out=None):
         import plaster
 
         self.uri = plaster.parse_uri(uri)

tests/test_scripts/test_common.py

@@ -1,5 +1,9 @@
+from plaster.exceptions import PlasterError
+import pytest
 import unittest
 
+import pyramid.scripts.common
+
 
 class TestParseVars(unittest.TestCase):
     def test_parse_vars_good(self):
@@ -14,3 +18,22 @@ def test_parse_vars_bad(self):
 
         vars = ['a']
         self.assertRaises(ValueError, parse_vars, vars)
+
+
+def test_get_config_loader_raises():
+    with pytest.raises(PlasterError):
+        pyramid.scripts.common.get_config_loader('invalidscheme:/foo')
+
+
+def test_get_config_loader_calls():
+    def reporter(text):
+        nonlocal reporter_called
+        reporter_called = True
+
+    reporter_called = False
+    with pytest.raises(SystemExit):
+        pyramid.scripts.common.get_config_loader(
+            'invalidscheme:/foo', reporter
+        )
+
+    assert reporter_called is True