[che-dev] How to configure new Single-host ?

[Michal Vala <mvala@xxxxxxxxxx>]

Hello Che devs,

we're finally actually coding the new single-host strategy with
Traefik gateway.

We currently have `che.infra.kubernetes.server_strategy` with options
`default-host`, `multi-host`, `single-host` and it is working only on
Kubernetes. With new single-host approach we won't be using
Ingresses/Routes for workspaces public endpoints, but we'll have only
a single Ingress/Route for the whole Che and doing all routing with
reverse-proxy (Traefik) that we will be configuring as we need.

My question is, how do we want to configure it? I see following options:

1] silently replace single-host strategy. Simply configuration would
be exactly the same, only with `single-host`, it will now use the new
approach with no fallback to old Ingress based. And it will ofcourse
work on OpenShift.

2] Introduce 4th strategy name. Something like `gateway-host`,
`che-host`, `single-route-host` (I don't like either of them. We would
make up something better if we choose this way)?

3] Have a second config option for single-host. So it will keep the
`che.infra.kubernetes.server_strategy` as is, but when it is set to
`single-host`, second config options came to play, something like
`che.infra.kubernetes.singlehost_strategy` with options `ingress` for
current implementation. For new impl either
`traefik`/`traefik-gateway` for more variability in case we would need
more gateway implementations. Or only `gateway` that would keep
underlying gateway implementation hidden.

4] other ideas?

I personally like the 3] as I think that `single-host` is a good name
that describes it well, and with the second config option, we will be
more future-proof. This might be important in cases we will need to
add/switch gateways, or for example some interesting single-host
strategies came up with IngressV2 or something new we currently don't
know about.

Thoughts?

Thanks!

-- 
Michal Vala
Software Engineer, Eclipse Che
Red Hat Czech