With this change, the nginx webserver serving the static files of the studio-client application, will accept only http2 requests. In order to accept HTTP/1.1 you need to set the environment variable PROTOCOL to an emtpy value.

Nginx cannot serve both protocols on the same port by upgrading the protocol during the handshake, therefore we need to tell Traefik to directly speak h2c by setting the label traefik.protocol: h2c on the container. Any healthcheck to this container using cUrl needs to set --http2-prior-knowledge on its requests.

To make this healthcheck work, the underlying nginx base image had to be updated to 1.19.2 .

To accept the environment variable in its configuration, the default.conf file is now a template as described in the DockerHub nginx image description.

(CMS-13480)