Rework entry points with importlib

Fix UserWarning: pkg_resources is deprecated as an API

Author: vallsv

Lima/Server/EnvHelper.py

@@ -33,11 +33,6 @@
 
 import PyTango
 
-try:
-    import pkg_resources
-except ImportError:
-    pkg_resources = None
-
 
 ModDepend = ["Core", "Espia"]
 Debug = 0
@@ -434,8 +429,25 @@ def get_entry_point(group: str, name: str):
     """
     Try to find an extension using entry points.
     """
-    if pkg_resources is None:
+    try:
+        from importlib.metadata import entry_points
+    except ImportError:
+        pass
+    else:
+        eps = entry_points()
+        plugins = eps.select(group=group, name=name)
+        if not plugins:
+            return None
+        elif len(plugins) > 1:
+            raise ValueError("found more than one entry point matching {}".format(name))
+        return plugins[0]
+
+    # Here is the old way to import plugins
+    try:
+        import pkg_resources
+    except ImportError:
         return None
+
     entry_points = tuple(pkg_resources.iter_entry_points(group, name))
     if not entry_points:
         return None

Lima/Server/camera/__init__.py

@@ -36,13 +36,24 @@ def _init_module():
                 if subdir:
                     base = "%s.%s" % (subdir, base)
                 cameras.append(base)
+
+    # New way to import entry points
     try:
-        import pkg_resources
+        from importlib.metadata import entry_points
     except ImportError:
-        pass
+        # Old way to import entry points
+        try:
+            import pkg_resources
+        except ImportError:
+            pass
+        else:
+            for ep in pkg_resources.iter_entry_points("Lima_tango_camera"):
+                cameras.append(ep.name)
     else:
-        for ep in pkg_resources.iter_entry_points("Lima_tango_camera"):
-            cameras.append(ep.name)
+        eps = entry_points()
+        for entry_point in eps.select(group="Lima_tango_camera"):
+            cameras.append(entry_point.value)
+
     return cameras
 
 

Lima/Server/plugins/__init__.py

@@ -38,13 +38,23 @@ def _init_module() -> list[str]:
                 if subdir:
                     base = "%s.%s" % (subdir, base)
                 plugins.append(base)
+
+    # New way to import entry points
     try:
-        import pkg_resources
+        from importlib.metadata import entry_points
     except ImportError:
-        pass
+        # Old way to import entry points
+        try:
+            import pkg_resources
+        except ImportError:
+            pass
+        else:
+            for ep in pkg_resources.iter_entry_points("Lima_tango_plugin"):
+                plugins.append(ep.name)
     else:
-        for ep in pkg_resources.iter_entry_points("Lima_tango_plugin"):
-            plugins.append(ep.name)
+        eps = entry_points()
+        for entry_point in eps.select(group="Lima_tango_plugin"):
+            plugins.append(entry_point.value)
 
     return plugins