Add ability to read secrets from files

api/src/routes/tasks.rs

@@ -1,4 +1,4 @@
-use std::env;
+use std::{env, fs};
 
 use axum::{extract, http::HeaderMap};
 use chrono::{Duration, Utc};
@@ -28,7 +28,17 @@ pub async fn cleanup<A: Adaptor>(
         .get("X-Cron-Key")
         .map(|k| k.to_str().unwrap_or_default().into())
         .unwrap_or_default();
-    let env_key = env::var("CRON_KEY").unwrap_or_default();
+    let env_key = if let Ok(key) = env::var("CRON_KEY") {
+        key
+    } else if let Some(path) = env::var_os("CRON_KEY_FILE") {
+        let Ok(key) = fs::read(&path) else {
+            println!("Error reading CRON_KEY_FILE at {path:?}");
+            return Err(ApiError::NotAuthorized);
+        };
+        String::from_utf8_lossy(key.as_slice()).into()
+    } else {
+        Default::default()
+    };
     if !env_key.is_empty() && cron_key_header != env_key {
         return Err(ApiError::NotAuthorized);
     }