Static file handler for aiohttp.web

aiohttp/web.py

@@ -1,11 +1,13 @@
 import asyncio
 import binascii
 import collections
+import mimetypes
 import cgi
 import http.cookies
 import io
 import json
 import re
+import os
 
 from urllib.parse import urlsplit, parse_qsl, unquote
 
@@ -893,6 +895,53 @@ def add_route(self, method, path, handler):
         compiled = re.compile('^' + pattern + '$')
         self._urls.append(Entry(compiled, method, handler))
 
+    def _static_file_handler_maker(self, path):
+        @asyncio.coroutine
+        def _handler(request):
+            resp = StreamResponse(request)
+            filename = request.match_info['filename']
+            filepath = os.path.join(path, filename)
+            if '..' in filename:
+                raise HTTPNotFound(request)
+            if not os.path.exists(filepath) or os.path.isdir(filepath):
+                raise HTTPNotFound(request)
+
+            ct = mimetypes.guess_type(filename)[0]
+            if not ct:
+                ct = 'application/octet-stream'
+            resp.content_type = ct
+
+            resp.headers['transfer-encoding'] = 'chunked'
+            resp.send_headers()
+
+            with open(filepath, 'rb') as f:
+                chunk = f.read(1024)
+                while chunk:
+                    resp.write(chunk)
+                    chunk = f.read(1024)
+
+            yield from resp.write_eof()
+            return resp
+
+        return _handler
+
+    def add_static(self, prefix, path):
+        """
+        Adds static files view
+        :param prefix - url prefix
+        :param path - folder with files
+        """
+        assert prefix.startswith('/')
+        assert os.path.exists(path), 'Path does not exist'
+        method = 'GET'
+        suffix = r'(?P<filename>.*)'  # match everything after static prefix
+        if not prefix.endswith('/'):
+            prefix += '/'
+        compiled = re.compile('^' + prefix + suffix + '$')
+        self._urls.append(Entry(
+            compiled, method, self._static_file_handler_maker(path)
+        ))
+
 
 ############################################################
 # Application implementation

tests/test_web_functional.py

@@ -3,6 +3,7 @@
 import os.path
 import socket
 import unittest
+import tempfile
 from aiohttp import web, request, FormData
 
 
@@ -23,9 +24,10 @@ def find_unused_port(self):
         return port
 
     @asyncio.coroutine
-    def create_server(self, method, path, handler):
+    def create_server(self, method, path, handler=None):
         app = web.Application(loop=self.loop, debug=True)
-        app.router.add_route(method, path, handler)
+        if handler:
+            app.router.add_route(method, path, handler)
 
         port = self.find_unused_port()
         srv = yield from self.loop.create_server(app.make_handler,
@@ -236,3 +238,32 @@ def go():
             self.assertEqual(200, resp.status)
 
         self.loop.run_until_complete(go())
+
+    def test_static_file(self):
+
+        @asyncio.coroutine
+        def go(tmpdirname, filename):
+            app, _, url = yield from self.create_server(
+                'GET', '/static/' + filename
+            )
+            app.router.add_static('/static', tmpdirname)
+
+            resp = yield from request('GET', url, loop=self.loop)
+            self.assertEqual(200, resp.status)
+            txt = yield from resp.text()
+            self.assertEqual('file content', txt)
+            ct = resp.headers['CONTENT-TYPE']
+            self.assertEqual('application/octet-stream', ct)
+
+            resp = yield from request('GET', url+'fake', loop=self.loop)
+            self.assertEqual(404, resp.status)
+            resp = yield from request('GET', url+'/../../', loop=self.loop)
+            self.assertEqual(404, resp.status)
+
+        with tempfile.TemporaryDirectory() as tmpdirname:
+            with tempfile.NamedTemporaryFile(dir=tmpdirname) as fp:
+                filename = os.path.basename(fp.name)
+                fp.write(b'file content')
+                fp.flush()
+                fp.seek(0)
+                self.loop.run_until_complete(go(tmpdirname, filename))