Added cli args

lantern/args.py

@@ -0,0 +1,9 @@
+import argparse
+
+
+def parse_args():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("handler", help="Executable to run", type=str)
+    parser.add_argument("--port", help="Port to listen on", type=int, default=8000)
+    parser.add_help = True
+    return parser.parse_args()

lantern/main.py

@@ -1,6 +1,7 @@
 from sanic import Sanic
 from sanic_useragent import SanicUserAgent
-from lantern.route import main_route
+from lantern.args import parse_args
+from lantern.route import build_main_route
 import os
 
 app = Sanic(__name__)
@@ -8,7 +9,9 @@ SanicUserAgent.init_app(app)
 
 
 def main():
+    args = parse_args()
     workers = os.cpu_count() or 1
+    main_route = build_main_route(args)
     app.add_route(main_route, "/<path>")
     app.add_route(main_route, "/")
-    app.run(host="0.0.0.0", port=8000, workers=workers)
+    app.run(host="0.0.0.0", port=args.port, workers=workers)

lantern/route.py

@@ -5,10 +5,16 @@ from lantern.request import serialize_request
 import os
 
 
-async def main_route(request, path=None):
-    handle = os.path.join(os.path.dirname(__file__), 'test_handle.py')
+def build_main_route(args):
+    handle = os.path.abspath(args.handler)
+    if not os.path.isfile(handle) or not os.access(handle, os.X_OK):
+        raise FileNotFoundError("Can't find handle at {}".format(handle))
+
+    async def main_route(request, path=None):
         result = execute_handle(handle, serialize_request(request))
         if result.exit_code != 0:
             return error_response(result.error)
 
         return html(result.html, status=200)
+
+    return main_route