README.md

@@ -15,4 +15,104 @@ Code Quality
 
 The code quality isn't the greatest/top tier. All code lives in the "main" package and should be moved at some point.
 
-Regardless, it is meant to be simple and easy to understand.
+Regardless, it is meant to be simple and easy to understand.
+
+Configuration
+-------------
+
+### Modes
+
+#### Redirect
+
+Standard redirect functionality
+
+#### Download Mapping
+
+Uses the `dl_map` configuration variable to enable mapping of paths to new paths.
+
+Think symlinks, but in a generated file.
+
+### Mirrors
+Mirror targets with trailing slash are placed in the yaml configuration file.
+
+### Example YAML
+```yaml
+# GeoIP Database Path
+geodb: GeoLite2-City.mmdb
+
+# Comment out to disable
+dl_map: userdata.csv
+
+# LRU Cache Size (in items)
+cacheSize: 1024
+
+# Server definition
+# Weights are just like nginx, where if it's > 1 it'll be chosen x out of x + total times
+# By default, the top 3 servers are used for choosing the best.
+# server = full url or host+path
+# weight = int
+# optional: latitude, longitude (float)
+servers:
+  - server: armbian.12z.eu/apt/
+  - server: armbian.chi.auroradev.org/apt/
+    weight: 15
+    latitude: 41.8879
+    longitude: -88.1995
+````
+
+## API
+
+`/status`
+
+Meant for a simple health check (nginx/etc can 502 or similar if down)
+
+`/reload`
+
+Flushes cache and reloads configuration and mapping. Requires reloadToken to be set in the configuration, and a matching token provided in `Authorization: Bearer TOKEN`
+
+`/mirrors`
+
+Shows all mirrors in the legacy (by region) format
+
+`/mirrors.json`
+
+Shows all mirrors in the new JSON format. Example:
+
+```json
+[
+  {
+    "available":true,
+    "host":"imola.armbian.com",
+    "path":"/apt/",
+    "latitude":46.0503,
+    "longitude":14.5046,
+    "weight":10,
+    "continent":"EU",
+    "lastChange":"2022-08-12T06:52:35.029565986Z"
+  }
+]
+```
+
+`/mirrors/{server}.svg`
+
+Magic SVG path to show badges based on server status, for use in dynamic mirror lists.
+
+`/dl_map`
+
+Shows json-encoded download mappings
+
+`/geoip`
+
+Shows GeoIP information for the requester
+
+`/region/REGIONCODE/PATH`
+
+Using this magic path will redirect to the desired region:
+
+* NA - North America
+* EU - Europe
+* AS - Asia
+
+`/metrics`
+
+Prometheus metrics endpoint. Metrics aren't considered private, thus are exposed to the public.