HTTP/3 in Docker Compose via Traefik

This repository contains a docker compose environment to test HTTP/3 compatibility with traefik.

To verify the setup you can run the following command

docker compose up -d
docker run --network="host" ymuski/curl-http3 curl --insecure --head --http3-only --retry 3 --retry-all-errors --fail https://whoami.localhost
docker compose down

Which should result in the following output:

(...)
HTTP/3 200 
content-type: text/plain; charset=utf-8
(...)

If you executed the commands above in very fast order, you may get a 404 error at first. This is because the docker-compose environment needs a few seconds to start up the webserver. But curl is configured to automatically retry the request 3 times via the --retry 3 --retry-all-errors --fail flags.

Test with your browser

If you want to test the HTTP/3 compatibility in your browser, you must make sure that the browser trusts the certificate.

One way to do this is to use mkcert:

1. install mkcert: https://github.com/FiloSottile/mkcert#installation
2. run mkcert -install
3. run mkcert whoami.localhost inside this repository (this should overwrite the default certificates whoami.localhost.pem and whoami.localhost-key.pem)
4. run docker-compose up

You should now be able to access https://whoami.localhost/ with your browser and verify that the HTTP/3 protocl was used via the network tab.

If you have trouble to enable HTTP/3 with your browser check Validating HTTP/3 Protocol Support on a Local Site for more information.