Improve plugin error handling

- Add mechanism to show plugin loading errors.
- Disable pluggy hooks for docs & unit tests

ksconf/consts.py

@@ -76,6 +76,7 @@ class _UNSET:
 # Environmental error
 EXIT_CODE_ENV_BUSTED = 120
 EXIT_CODE_BAD_PY_VERSION = 121
+EXIT_CODE_BROKEN_PLUGIN = 122
 
 
 # This gets properly supported in Python 3.6, but until then....

ksconf/hook.py

@@ -3,13 +3,18 @@
 
 from pluggy import HookimplMarker, PluginManager
 
-from ksconf.consts import PLUGGY_DISABLE_HOOK, PLUGGY_HOOK, is_debug
+from ksconf.consts import EXIT_CODE_BROKEN_PLUGIN, PLUGGY_DISABLE_HOOK, PLUGGY_HOOK, is_debug
 from ksconf.hookspec import KsconfHookSpecs
 
 # decorator to mark ksconf hooks
 ksconf_hook = HookimplMarker(PLUGGY_HOOK)
 
 
+class BadPluginWarning(UserWarning):
+    """ Issue with one or more plugins """
+    pass
+
+
 class _plugin_manager:
     """
     Lazy loading PluginManager proxy that allows simple module-level access to
@@ -27,7 +32,7 @@ def log(self, message):
 
     def _startup(self):
         # This runs on demand, exactly once.
-        pm = PluginManager(PLUGGY_HOOK)
+        self.__plugin_manager = pm = PluginManager(PLUGGY_HOOK)
 
         if PLUGGY_DISABLE_HOOK in os.environ:
             disabled_hooks = os.environ[PLUGGY_DISABLE_HOOK].split()
@@ -36,8 +41,27 @@ def _startup(self):
                 pm.set_blocked(hook)
 
         pm.add_hookspecs(KsconfHookSpecs)
-        pm.load_setuptools_entrypoints("ksconf_plugin")
-        self.__plugin_manager = pm
+
+        # Disable *ALL* 'ksconf_plugin' hooks
+        disabled_things = os.environ.get("KSCONF_DISABLE_PLUGINS", "").split()
+        self.log(f"Disabled stuff:   {disabled_things }")
+        if "ksconf_plugin" in disabled_things:
+            if is_debug:
+                self.log("All plugins are disabled")
+            return
+
+        # XXX: Find a way to report *which* plugin failed.  For now, use traceback
+        try:
+            pm.load_setuptools_entrypoints("ksconf_plugin")
+        except ModuleNotFoundError as e:
+            self.log("Unable to load one or more ksconf plugins.  "
+                     f"Please correct or uninstall the offending plugin.\n  {e}\n"
+                     "Run with KSCONF_DEBUG=1 to see a traceback")
+            if is_debug():
+                raise e
+            else:
+                sys.exit(EXIT_CODE_BROKEN_PLUGIN)
+
         # Maybe this should be it's own setting someday?  (disconnected from KSCONF_DEBUG)
         if is_debug():
             self.enable_monitoring()

ksconf/setup_entrypoints.py

@@ -14,7 +14,14 @@
 class Ep(NamedTuple):
     name: str
     module_name: str
-    object_name: str
+    object_name: str = None
+
+    @property
+    def formatted(self):
+        if self.object_name is None:
+            return f"{self.name} = {self.module_name}"
+        else:
+            return f"{self.name} = {self.module_name}:{self.object_name}"
 
 
 # autopep8: off
@@ -49,7 +56,7 @@ def get_entrypoints_setup():
     """ Build entry point text descriptions for ksconf packaging """
     setup = {}
     for (group, entries) in _entry_points.items():
-        setup[group] = [f"{ep.name} = {ep.module_name}:{ep.object_name}" for ep in entries]
+        setup[group] = [ep.formatted for ep in entries]
     return setup
 
 
@@ -78,10 +85,13 @@ def get_entrypoints_fallback(group):
 def debug():
     # For debugging internally defined entrypoints
     print("Builtin entrypoints:")
-    for (_, entries) in _entry_points.items():
-        print("[group]")
+    for (group, entries) in _entry_points.items():
+        print(f"[{group}]")
         for ep in entries:
-            print(f"{ep.name:15} = {ep.module_name:30} : {ep.object_name}")
+            if ep.object_name:
+                print(f"{ep.name:15} = {ep.module_name:30} : {ep.object_name}")
+            else:
+                print(f"{ep.name:15} = {ep.module_name:30}")
         print("")
 
 

make_dyn_docs.py

@@ -18,7 +18,7 @@
     "PYTHONWARNINGS": "ignore",
     "PYTHONIOENCODING": "utf-8",
     "PYTHONHASHSEED": "1",
-    "KSCONF_DISABLE_PLUGINS": "ksconf_cmd",
+    "KSCONF_DISABLE_PLUGINS": "ksconf_cmd ksconf_plugin",
 }
 
 

run_tests.py

@@ -22,7 +22,7 @@
         del os.environ[k]
 
 # Tell KSCONF cmd loaders to use the locally defined list, and ignore externally defined commands
-os.environ["KSCONF_DISABLE_PLUGINS"] = "ksconf_cmd"
+os.environ["KSCONF_DISABLE_PLUGINS"] = "ksconf_cmd ksconf_plugin"
 
 
 def run_all():