It's a reverse HTTP Tunnel using QUIC:
K8S apiserver / curl --- TCP ----> [proxy-server] ---- QUIC ----> [proxy-agent]---TCP--> [kubelet]
- the proxy-server listens for
tcp
(no HTTP server running) andquic
. - The proxy-agent talks to the server and opens a
quic
session. - It starts a HTTP tunnel server that listens on that session for new streams.
- When the API server / curl talks to the proxy-server, it creates a new
quic
stream and sends the data to the proxy-agent. - The HTTP server in the proxy-agent that listens on new quic streams accepts the stream, opens TCP connection to the requested host (from the CONNECT) and pipes the data back.
The proxy can also run as a simple passthrough proxy via client-tcp
Run the server:
$ make start-server
2020/11/01 02:11:39 quick listener on 0.0.0.0:8888
2020/11/01 02:11:39 tcp listener on 0.0.0.0:10443
2020/11/01 02:11:39 waiting for new quic client session
2020/11/01 02:11:39 waiting for tcp client connections
in another terminal run the client:
$ make start-client
2020/11/01 02:13:31 dialing quic server...
2020/11/01 02:13:31 starting http server
and in third try to access it:
curl -p --proxy localhost:10443 http://www.example.com
If you want to test the passthrough proxy instead:
$ make start-client-tcp
2020/11/25 12:07:07 dialing quic server...
2020/11/25 12:07:07 connected to quic server
Docker images are available at:
ghcr.io/gardener/quic-reverse-http-tunnel/quic-server:latest
ghcr.io/gardener/quic-reverse-http-tunnel/quic-client:latest
ghcr.io/gardener/quic-reverse-http-tunnel/quic-client-tcp:latest
If you want to use a specific version tag, check the tags
of the gardener/quic-reverse-http-tunnel repository.
A github action takes care of building and pushing new images to ghcr.io
when a new github tag is created.
To build the images locally, you can use the make docker-images
command:
REGISTRY=<your-registry> IMAGE_TAG=<your-image-tag> make docker-images
Note that if you do not specify the REGISTRY
and IMAGE_TAG
variables, the default ones from the Makefile
will be used.