Allow all settings to be set via env variables

README.md

@@ -132,11 +132,13 @@ If you configure FediFetcher this way, it'll fetch missing remote replies to the
 
 #### Advanced Options
 
-Please find the list of all configuration options, including descriptions, below:
+Below is a list of all configuration options, including their descriptions.
+Please note that configuration options may also be specified as environment variables starting with the prefix `FF_`, case-insensitive, and with `-` replaced with `_`.
+For example `max-favourites` can be set via `FF_MAX_FAVOURITES` or `ff_max_favourites`)
 
 Option | Required? | Notes |
 |:----------------------------------------------------|-----------|:------|
-|`access-token` | Yes | The access token. If using GitHub action, this needs to be provided as a Secret called  `ACCESS_TOKEN`. If running as a cron job or a container, you can supply this option as array, to [fetch posts for multiple users](https://blog.thms.uk/2023/04/muli-user-support-for-fedifetcher) on your instance. You may also provide this option as an environment variable starting with `ACCESS_TOKEN`. To fetch posts for multiple users, define multiple environment variables, eg. `ACCESS_TOKEN_USER1=…` and `ACCESS_TOKEN_USER2=…`|
+|`access-token` | Yes | The access token. If using GitHub action, this needs to be provided as a Secret called  `ACCESS_TOKEN`. If running as a cron job or a container, you can supply this option as array, to [fetch posts for multiple users](https://blog.thms.uk/2023/04/muli-user-support-for-fedifetcher) on your instance. To set tokens for multiple users using environment variables, define multiple environment variables with `FF_ACCESS_TOKEN` prefix, eg. `FF_ACCESS_TOKEN_USER1=…` and `FF_ACCESS_TOKEN_USER2=…`|
 |`server`|Yes|The domain only of your mastodon server (without `https://` prefix) e.g. `mstdn.thms.uk`. |
 |`home-timeline-length` | No | Provide to fetch remote replies to posts in the API-Key owner's home timeline. Determines how many posts we'll fetch replies for. Recommended value: `200`.
 | `max-bookmarks` | No | Provide to fetch remote replies to any posts you have bookmarked. Determines how many of your bookmarks you want to get replies to. Recommended value: `80`. Requires an access token with `read:bookmarks` scope.

find_posts.py

@@ -1488,7 +1488,26 @@ def fetch_timeline_context(timeline_posts, token, parsed_urls, seen_hosts, seen_
             logger.critical(f"Config file {arguments.config} doesn't exist")
             sys.exit(1)
 
-    if tokens := [token for envvar, token in os.environ.items() if envvar.startswith("ACCESS_TOKEN")]:
+    for envvar, value in os.environ.items():
+        envvar = envvar.lower()
+        if envvar.startswith("ff_") and not envvar.startswith("ff_access_token"):
+            envvar = envvar[3:]
+            # most settings are numerical
+            if envvar not in [
+                "server",
+                "lock_file",
+                "state_dir",
+                "on_start",
+                "on_done",
+                "on_fail",
+                "log_level",
+                "log_format"
+            ]:
+                value = int(value)
+            setattr(arguments, envvar, value)
+
+    # remains special-cased for specifying multiple tokens
+    if tokens := [token for envvar, token in os.environ.items() if envvar.lower().startswith("ff_access_token")]:
         arguments.access_token = tokens
 
     logger.info(f"Starting FediFetcher")