Arvados

Use case:

User has an Arvados appliance and another computer with a browser on the same network. They would like to access Arvados.

Idea:

Arvados advertises itself on the local network using DNS-SD. This is provided on Linux with the "avahi" daemon. This can be done using the "avahi-publish" utility.

On the client desktop, the user runs a utility which bootstraps the Arvados access:

1. Discover Arvados on the local network

2. If Arvados is using a private certificate authority, fetch and install the private root certificate (perhaps requiring a pairing process so you don't accept a root certificate from just anyone).

3. Open the browser to the correct URL and configure local settings with the right ARVADOS_API_HOST.

Notes:

Hostnames published this way end in ".local", e.g. the client can resolve "arva2.local".

However, what Arvados publishes as "ExternalURL" needs to resolvable by the client. Might be able to set up an alias so that all the "ExternalURL" hostnames point to the intended ".local" hostname.

A related approach is to use Tailscale (#22427), but using DNS-SD has the advantage of not depending on external infrastructure at all.