Whenever cloudflared receives a SIGTERM or SIGINT it goes into graceful shutdown mode, which unregisters the connection and closes the control stream. Unregistering makes it so we no longer receive any new requests and makes the edge close the connection, allowing in-flight requests to finish (within a 3 minute period).
This was working fine for http2 connections, but the quic proxy was cancelling the context as soon as the controls stream ended, forcing the process to stop immediately.
This commit changes the behavior so that we wait the full grace period before cancelling the request
This PR changes protocol initialization of the other N connections to be
the same as the one we know the initial tunnel connected with. This is
so we homogenize connections and not lead to some connections being
QUIC-able and the others not.
There's also an improvement to the connection registered log so we know
what protocol every individual connection connected with from the
cloudflared side.
cloudflared falls back aggressively to HTTP/2 protocol if a connection
attempt with QUIC failed. This was done to ensure that machines with UDP
egress disabled did not stop clients from connecting to the cloudlfare
edge. This PR improves on that experience by having cloudflared remember
if a QUIC connection was successful which implies UDP egress works. In
this case, cloudflared does not fallback to HTTP/2 and keeps trying to
connect to the edge with QUIC.
cloudflared falls back aggressively to HTTP/2 protocol if a connection
attempt with QUIC failed. This was done to ensure that machines with UDP
egress disabled did not stop clients from connecting to the cloudlfare
edge. This PR improves on that experience by having cloudflared remember
if a QUIC connection was successful which implies UDP egress works. In
this case, cloudflared does not fallback to HTTP/2 and keeps trying to
connect to the edge with QUIC.
This adds various bug fixes when investigating why QUIC transports were
not being unregistered when they should (and only when the graceful shutdown
started).
Most of these bug fixes are making the QUIC transport implementation closer
to its HTTP2 counterpart:
- ServeControlStream is now a blocking function (it's up to the transport to handle that)
- QUIC transport then handles the control plane as part of its Serve, thus waiting for it on shutdown
- QUIC transport now returns "non recoverable" for connections with similar semantics to HTTP2 and H2mux
- QUIC transport no longer has a loop around its Serve logic that retries connections on its own (that logic is upstream)
ServeControlStream accidentally became non-blocking in the last quic
change causing stream to not be returned until a SIGTERM was received.
This change makes ServeControlStream be non-blocking for QUIC streams.
GoncaloGarcia
Devin Carr
Sudarsan Reddy
João Oliveirinha
cthuang
Nuno Diegues