Use importlib.resources instead of deprecated pkg_resources

Author: amotl

mqttwarn/core.py

@@ -1,5 +1,10 @@
 # -*- coding: utf-8 -*-
 # (c) 2014-2023 The mqttwarn developers
+try:
+    from importlib.resources import files as resource_files  # type: ignore[attr-defined]
+except ImportError:
+    from importlib_resources import files as resource_files  # type: ignore[no-redef]
+
 import logging
 import os
 import socket
@@ -14,7 +19,6 @@
 import paho.mqtt.client as paho
 from paho.mqtt.client import Client as MqttClient
 from paho.mqtt.client import MQTTMessage
-from pkg_resources import resource_filename
 
 import mqttwarn.configuration
 from mqttwarn.context import FunctionInvoker, RuntimeContext
@@ -594,7 +598,9 @@ def load_services(services):
             if module == "http":
                 module = "http_urllib"
             logger.debug('Trying to load built-in service "{}" from "{}"'.format(service, module))
-            modulefile_candidates = [resource_filename("mqttwarn.services", module + ".py")]
+            service_filename = module + ".py"
+            service_filepath = resource_files("mqttwarn.services") / service_filename
+            modulefile_candidates = [service_filepath]
 
         success = False
         for modulefile in modulefile_candidates:
@@ -610,9 +616,9 @@ def load_services(services):
                 logger.exception(f'Loading service "{service}" from file "{modulefile}" failed')
 
         if not success:
-            logger.critical('Unable to load service "{}"'.format(service))
-            # TODO: Review this.
-            sys.exit(1)
+            msg = "Failed loading service: {}".format(service)
+            logger.critical(msg)
+            raise ImportError(msg)
 
 
 def connect():

mqttwarn/util.py

@@ -1,6 +1,12 @@
 # (c) 2014-2023 The mqttwarn developers
 import functools
 import importlib.machinery
+
+try:
+    from importlib.resources import files as resource_files  # type: ignore[attr-defined]
+except ImportError:
+    from importlib_resources import files as resource_files  # type: ignore[no-redef]
+
 import importlib.util
 import json
 import logging
@@ -12,7 +18,6 @@
 from pathlib import Path
 
 import funcy
-import pkg_resources
 from six import string_types
 
 if t.TYPE_CHECKING:
@@ -128,19 +133,20 @@ def sanitize_function_name(name: str) -> str:
     raise ValueError(f"Invalid function name: {name}")
 
 
-def load_module_from_file(path: str) -> types.ModuleType:
+def load_module_from_file(path: t.Union[str, Path]) -> types.ModuleType:
     """
     http://code.davidjanes.com/blog/2008/11/27/how-to-dynamically-load-python-code/
 
     :param path:
     :return:
     """
-    name = Path(path).stem
+    path = Path(path)
+    name = path.stem
     loader: "FileLoader"
-    if path.endswith(".py"):
-        loader = importlib.machinery.SourceFileLoader(fullname=name, path=path)
-    elif path.endswith(".pyc"):
-        loader = importlib.machinery.SourcelessFileLoader(fullname=name, path=path)
+    if path.suffix == ".py":
+        loader = importlib.machinery.SourceFileLoader(fullname=name, path=str(path))
+    elif path.suffix == ".pyc":
+        loader = importlib.machinery.SourcelessFileLoader(fullname=name, path=str(path))
     else:
         raise ImportError(f"Loading file failed (only .py and .pyc): {path}")
     spec = importlib.util.spec_from_loader(loader.name, loader)
@@ -235,8 +241,8 @@ def load_function(name: str, py_mod: t.Optional[types.ModuleType]) -> t.Callable
 
 
 def get_resource_content(package: str, filename: str) -> str:
-    with pkg_resources.resource_stream(package, filename) as stream:
-        return stream.read().decode("utf-8")
+    path = resource_files(package) / filename
+    return path.read_text()
 
 
 def truncate(s: t.Union[str, bytes], limit: int = 200, ellipsis="...") -> str:

setup.py

@@ -16,6 +16,7 @@
     "funcy<3",
     "future>=0.18.0,<1",
     "importlib-metadata; python_version<'3.8'",
+    "importlib-resources; python_version<'3.8'",
     "jinja2<4",
     "paho-mqtt<2",
     "requests<3",

tests/test_core_infra.py

@@ -709,11 +709,11 @@ def test_load_services_spec_not_found(caplog):
     config = Config()
     config.add_section("config:foo.bar")
     bootstrap(config=config)
-    with pytest.raises(SystemExit) as ex:
+    with pytest.raises(ImportError) as ex:
         load_services(["foo.bar"])
     assert 'Loading service "foo.bar" from module "foo.bar" failed' in caplog.messages
-    assert 'Unable to load service "foo.bar"' in caplog.messages
-    assert ex.match("1")
+    assert "Failed loading service: foo.bar" in caplog.messages
+    assert ex.match("Failed loading service: foo.bar")
 
 
 def test_load_services_file_not_found(tmp_path, caplog):
@@ -728,12 +728,12 @@ def test_load_services_file_not_found(tmp_path, caplog):
     config.add_section("config:foo.bar")
     config.set("config:foo.bar", "module", "foo_bar.py")
     bootstrap(config=config)
-    with pytest.raises(SystemExit) as ex:
+    with pytest.raises(ImportError) as ex:
         load_services(["foo.bar"])
     assert 'Module "foo_bar.py" is not a file' in caplog.messages
     assert f'Module "{modulefile}" is not a file' in caplog.messages
-    assert 'Unable to load service "foo.bar"' in caplog.messages
-    assert ex.match("1")
+    assert "Failed loading service: foo.bar" in caplog.messages
+    assert ex.match("Failed loading service: foo.bar")
 
 
 def test_load_services_file_failure(tmp_path, caplog):
@@ -751,12 +751,12 @@ def test_load_services_file_failure(tmp_path, caplog):
     config.set("config:foo.bar", "module", "foo_bar.py")
     bootstrap(config=config)
 
-    with pytest.raises(SystemExit) as ex:
+    with pytest.raises(ImportError) as ex:
         load_services(["foo.bar"])
     assert f'Loading service "foo.bar" from file "{modulefile}" failed' in caplog.text
     assert "AssertionError" in caplog.text
-    assert 'Unable to load service "foo.bar"' in caplog.messages
-    assert ex.match("1")
+    assert "Failed loading service: foo.bar" in caplog.messages
+    assert ex.match("Failed loading service: foo.bar")
 
 
 def test_run_plugin_success(caplog):