Use python-dotenv to read in env vars

.gitignore

@@ -1,5 +1,6 @@
-# Project spesific ignores
+# Project specific ignores
 tests/resources/*.json
+src/datadoc/.env.dev
 
 # Byte-compiled / optimized / DLL files
 __pycache__/

src/datadoc/.env.default

@@ -0,0 +1 @@
+JUPYTERHUB_USER=

src/datadoc/backend/datadoc_metadata.py

@@ -3,14 +3,14 @@
 
 import json
 import logging
-import os
 import pathlib
 import typing as t
 import uuid
 from typing import TYPE_CHECKING
 
 from datadoc_model import model
 
+from datadoc import config
 from datadoc.backend.dataset_parser import DatasetParser
 from datadoc.backend.model_backwards_compatibility import upgrade_metadata
 from datadoc.backend.storage_adapter import StorageAdapter
@@ -23,6 +23,7 @@
 from datadoc.utils import get_timestamp_now
 
 if TYPE_CHECKING:
+    import os
     from datetime import datetime
 
 logger = logging.getLogger(__name__)
@@ -78,9 +79,8 @@ def __init__(
 
             self.extract_metadata_from_files()
 
-        try:
-            self.current_user = os.environ["JUPYTERHUB_USER"]
-        except KeyError:
+        self.current_user = config.get_jupyterhub_user()
+        if not self.current_user:
             self.current_user = PLACEHOLDER_USERNAME
             logger.warning(
                 "JUPYTERHUB_USER env variable not set, using %s as placeholder",

src/datadoc/config.py

@@ -0,0 +1,17 @@
+"""Centralised configuration management for Datadoc."""
+from __future__ import annotations
+
+import os
+
+from dotenv import dotenv_values
+
+_config: dict[str, str | None] = {
+    **dotenv_values(".env.default"),  # load default config
+    **dotenv_values(".env.dev"),  # load local dev config
+    **os.environ,  # override loaded values with environment variables
+}
+
+
+def get_jupyterhub_user() -> str | None:
+    """Get the JupyterHub user name."""
+    return _config.get("JUPYTERHUB_USER")