fix(server): Support HTTP half-close connections

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 - Enforce rate limits for monitor check-ins. ([#2065](https://github.com/getsentry/relay/pull/2065))
 - Allow rate limits greater than `u32::MAX`. ([#2079](https://github.com/getsentry/relay/pull/2079))
+- Do not drop envelope when client closes connection. ([#2089](https://github.com/getsentry/relay/pull/2089))
 
 **Features**:
 

relay-server/src/actors/server.rs

@@ -93,7 +93,7 @@ impl Service for HttpServer {
             .into_make_service_with_connect_info::<SocketAddr>();
 
         let http_config = HttpConfig::new()
-            .http1_half_close(false)
+            .http1_half_close(true)
             .http1_header_read_timeout(CLIENT_HEADER_TIMEOUT)
             .http1_writev(true)
             .http2_keep_alive_timeout(config.keepalive_timeout())

tests/integration/test_envelope.py

@@ -17,6 +17,41 @@ def test_envelope(mini_sentry, relay_chain):
     assert event["logentry"] == {"formatted": "Hello, World!"}
 
 
+def test_envelope_close_connection(mini_sentry, relay):
+    """Prematurely closing the TCP connection on the client side does not drop the envelope"""
+    import socket
+    import time
+
+    mini_sentry.add_basic_project_config(42)
+    dsn_key = mini_sentry.get_dsn_public_key(42, 0)
+    relay = relay(mini_sentry)
+
+    # Prepare POST data:
+    body_template = """{"event_id": "9ec79c33ec9942ab8353589fcb2e04dc","dsn": "https://%s:@sentry.io/42"}
+{"type":"attachment","length":11,"content_type":"text/plain","filename":"hello.txt"}
+Hello World
+"""
+
+    # Run multiple times to cover potential test flakiness.
+    num_iterations = 10
+    for _ in range(num_iterations):
+        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        sock.connect(relay.server_address)
+
+        body = body_template % dsn_key
+        req = f"""POST /api/42/envelope/ HTTP/1.1\r\nContent-Length: {len(body)}\r\n\r\n{body}""".encode()
+        sock.send(req)
+
+        time.sleep(0.0001)  # Give relay time to start processing event
+
+        sock.close()  # Close the connection
+
+    for _ in range(num_iterations):
+        envelope = mini_sentry.captured_events.get(timeout=1)
+        assert envelope
+    assert mini_sentry.captured_events.empty()
+
+
 def test_envelope_empty(mini_sentry, relay):
     relay = relay(mini_sentry)
     PROJECT_ID = 42