Update standalone dockerfile and add support for config via env vars

maubot/standalone/Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.io/alpine:3.11
+FROM docker.io/alpine:3.14
 
 RUN apk add --no-cache \
       py3-aiohttp \

maubot/standalone/__main__.py

@@ -27,7 +27,7 @@ from ruamel.yaml import YAML
 from ruamel.yaml.comments import CommentedMap
 import sqlalchemy as sql
 
-from mautrix.util.config import RecursiveDict
+from mautrix.util.config import RecursiveDict, BaseMissingError
 from mautrix.util.db import Base
 from mautrix.types import (UserID, Filter, RoomFilter, RoomEventFilter, StrippedStateEvent,
                            EventType, Membership)
@@ -55,6 +55,8 @@ config = Config(args.config, args.base_config)
 config.load()
 try:
     config.update()
+except BaseMissingError:
+    print("No example config found, not updating config")
 except Exception as e:
     print("Failed to update config:", e)
 

maubot/standalone/config.py

@@ -17,6 +17,12 @@ from mautrix.util.config import BaseFileConfig, ConfigUpdateHelper
 
 
 class Config(BaseFileConfig):
+    def __getitem__(self, key: str) -> Any:
+        try:
+            return os.environ[f"MAUBOT_{key.replace('.', '_').upper()}"]
+        except KeyError:
+            return super().__getitem__(key)
+
     def do_update(self, helper: ConfigUpdateHelper) -> None:
         copy, _, base = helper
         copy("user.credentials.id")