feat: add CLI arguments + env variables support

editor/server.py

@@ -1,15 +1,38 @@
-from http import HTTPStatus
-from http.server import  SimpleHTTPRequestHandler
+#!/usr/bin/env python3
+
+import argparse
 import json
 import os
 import socketserver
+from http import HTTPStatus
+from http.server import SimpleHTTPRequestHandler
 from typing import Optional
-from urllib.parse import urlparse, parse_qs, unquote
+from urllib.parse import parse_qs, unquote, urlparse
+
+
+# https://stackoverflow.com/a/10551190/11109181
+class EnvDefault(argparse.Action):
+    def __init__(self, envvar, required=True, default=None, help=None, **kwargs):
+        if envvar:
+            if envvar in os.environ:
+                default = os.environ[envvar]
+        if required and default is not None:
+            required = False
+        
+        if default is not None and help is not None:
+            help += f" (default: {default})"
+        
+        if envvar and help is not None:
+            help += f"\nCan also be specified through the {envvar} environment variable"
+        super(EnvDefault, self).__init__(default=default, required=required, help=help, 
+                                         **kwargs)
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        setattr(namespace, self.dest, values)
 
-PORT = 8000
-MAX_SIZE = 10e6
 
 class MyHandler(SimpleHTTPRequestHandler):
+    MAX_PAYLOAD_SIZE = 1e6
     DATA_DIR = "metadata"
     CACHE = {}
     
@@ -25,9 +48,9 @@ class MyHandler(SimpleHTTPRequestHandler):
     def read_body_data(self):
         try:
             size: int = int(self.headers["Content-Length"])
-            if size > MAX_SIZE:
+            if size > self.MAX_PAYLOAD_SIZE:
                 self.send_error(HTTPStatus.CONTENT_TOO_LARGE)
-                self.log_error(f"Payload is too big ({MAX_SIZE=}B)")
+                self.log_error(f"Payload is too big ({self.MAX_PAYLOAD_SIZE=}B)")
                 return False
             raw_data = self.rfile.read(size)
             self.data = json.loads(raw_data)
@@ -149,8 +172,42 @@ class MyHandler(SimpleHTTPRequestHandler):
 
 
 def main():
-    with socketserver.TCPServer(("", PORT), MyHandler) as httpd:
-        print(f"Serving on port {PORT}")
+    parser = argparse.ArgumentParser(
+        description="Starts the Melies server",
+        formatter_class=argparse.RawTextHelpFormatter
+    )
+    parser.add_argument(
+        "-p", "--port",
+        action=EnvDefault,
+        envvar="MELIES_PORT",
+        default=8000,
+        type=int,
+        help="Port on which the server listens"
+    )
+    parser.add_argument(
+        "--max-payload-size",
+        action=EnvDefault,
+        envvar="MELIES_MAX_PAYLOAD_SIZE",
+        default=1e6,
+        type=int,
+        help="Maximum POST payload size in bytes that the server accepts"
+    )
+    parser.add_argument(
+        "--metadata-dir",
+        action=EnvDefault,
+        envvar="MELIES_METADATA_DIR",
+        default="metadata",
+        help="Path to the directory containing metadata files"
+    )
+    args = parser.parse_args()
+    
+    
+    port = args.port
+    MyHandler.MAX_PAYLOAD_SIZE = args.max_payload_size
+    MyHandler.DATA_DIR = args.metadata_dir
+    
+    with socketserver.TCPServer(("", port), MyHandler) as httpd:
+        print(f"Serving on port {port}")
         httpd.serve_forever()