[#5] Implement plugin-based system for reporter

Signed-off-by: Vladimir Domnich <v.domnich@yadro.com>

src/neofs_testlib/__init__.py

@@ -1 +1,60 @@
+import json
+import os
+import sys
+from typing import Any, Optional
+
+import yaml
+
+from neofs_testlib.reporter import set_reporter
+
+if sys.version_info < (3, 10):
+    from importlib_metadata import entry_points
+else:
+    from importlib.metadata import entry_points
+
+
 __version__ = "0.1.0"
+
+
+def __read_config() -> dict[str, Any]:
+    """
+    Loads configuration of library from default file .neofs-testlib.yaml or from
+    the file configured via environment variable NEOFS_TESTLIB_CONFIG.
+    """
+    file_path = os.getenv("NEOFS_TESTLIB_CONFIG", ".neofs-testlib.yaml")
+    if os.path.exists(file_path):
+        _, extension = os.path.splitext(file_path)
+        if extension == ".yaml":
+            with open(file_path, "r") as file:
+                return yaml.full_load(file)
+        if extension == ".json":
+            with open(file_path, "r") as file:
+                return json.load(file)
+    return {}
+
+
+def __load_plugin(group: str, name: Optional[str]) -> Any:
+    """
+    Loads plugin using entry point specification.
+    """
+    if not name:
+        return None
+    plugins = entry_points(group=group)
+    if name not in plugins.names:
+        return None
+    plugin = plugins[name]
+    return plugin.load()
+
+
+def __init_lib():
+    """
+    Initializes singleton components in the library.
+    """
+    config = __read_config()
+
+    reporter = __load_plugin("neofs.testlib.reporter", config.get("reporter"))
+    if reporter:
+        set_reporter(reporter)
+
+
+__init_lib()