tests/e2e: add HTTP response cache e2e tests

tests/e2e/scripts/http_cache_backend.py

@@ -0,0 +1,20 @@
+from http.server import BaseHTTPRequestHandler, HTTPServer
+
+_counter = 0
+
+
+class Handler(BaseHTTPRequestHandler):
+    def do_GET(self):
+        global _counter
+        _counter += 1
+        body = b"cache-test-%d" % _counter
+        self.send_response(200)
+        self.send_header("Content-Length", str(len(body)))
+        self.end_headers()
+        self.wfile.write(body)
+
+    def log_message(self, format, *args):
+        return
+
+
+HTTPServer(("0.0.0.0", 5677), Handler).serve_forever()

tests/e2e/scripts/http_cache_servestale_backend.py

@@ -0,0 +1,46 @@
+from http.server import BaseHTTPRequestHandler, HTTPServer
+import socket
+import threading
+
+_counter = 0
+_http_server = None
+
+
+class Handler(BaseHTTPRequestHandler):
+    def do_GET(self):
+        global _counter
+        _counter += 1
+        body = b"cache-test-%d" % _counter
+        self.send_response(200)
+        self.send_header("Content-Length", str(len(body)))
+        self.send_header("Connection", "close")
+        self.end_headers()
+        self.wfile.write(body)
+        threading.Thread(target=stop_server, daemon=True).start()
+
+    def log_message(self, format, *args):
+        return
+
+
+def stop_server():
+    global _http_server
+    if _http_server:
+        _http_server.shutdown()
+        _http_server.server_close()
+
+
+def start_raw_acceptor():
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    sock.bind(("0.0.0.0", 5676))
+    sock.listen(5)
+    while True:
+        conn, addr = sock.accept()
+        conn.close()
+
+
+_http_server = HTTPServer(("0.0.0.0", 5676), Handler)
+_http_server.serve_forever()
+_http_server.server_close()
+
+start_raw_acceptor()