Add tile recache script

maintenance/tiles/recache.py

@@ -0,0 +1,69 @@
+#!/usr/bin/env python3
+
+"""
+    See bottom of script or run
+        python recache.py -h
+    for usage instructions
+"""
+
+import argparse
+from pathlib import Path
+import re
+import sys
+
+import requests
+
+
+def clear_cache(cache_dir: Path, tile: str):
+    try:
+        (cache_dir / tile).unlink()
+    except:
+        print(f"Warning: cached tile {tile} did not exist", file=sys.stderr)
+
+def recreate_tile(hostname: str, port: int, tile: str):
+    tile_url = f'{hostname}/tiles/{tile}'
+    req = requests.get(tile_url)
+    if req.status_code != 200:
+        raise Exception(f"Tile request for tile {tile} returned status {req.status_code} (data: {req.json()})")
+
+
+def main(cache_dir: Path, tile_list: Path, hostname: str, port: int):
+    assert cache_dir.exists(), "The supplied cache dir does not exist"
+    assert tile_list.exists(), "The supplied tile list file does not exist"
+
+    tiles = tile_list.read_text().splitlines()
+
+    for tile in tiles:
+        match = re.match(r'^(\w+)/(\d{1,2})/(\d+)/(\d+)(@\dx)?\.png$', tile)
+        assert match, f"Tile line {tile} does not  match required format"
+
+        clear_cache(cache_dir, tile)
+        recreate_tile(hostname, port, tile)
+
+        print(tile)
+
+
+if __name__=='__main__':
+    parser = argparse.ArgumentParser(
+        '''
+        Re-cache map tiles listed in a file.
+
+        Each line of the file should be of the format:
+            [tileset]/[zoom]/[z]/[x]/[y][scale?].png
+        E.g.
+            date_year/16/32812/21775.png
+            date_year/16/32810/21811@2x.png
+        etc
+
+        The order of lines in the file determines the order of re-caching.
+        Names of re-cached tiles are printed to standard output.
+        ''')
+
+    parser.add_argument('cache_directory', type=Path, help='The root directory of the tile cache (needs to be local)')
+    parser.add_argument('tile_list', type=Path, help='Path to the list of tiles that should be re-cached.')
+    parser.add_argument('--hostname', type=str, default="127.0.0.1", help='The hostname of the tile server')
+    parser.add_argument('--port', type=int, default=3000, help='The port numbre of the tile server')
+
+    args = parser.parse_args()
+
+    main(args.cache_directory, args.tile_list, args.hostname, args.port)