Allow specifying multiple hosts for kamal-proxy via an array

[kpumuk]

Currently, the way to specify multiple hosts for kamal-proxy is via the comma-separated value passed to host argument:

host: foo.example.com,bar.example.com

This leads to frustration when users accidentally enter hosts via more idiomatic array. This MR allows to use both host and hosts, where the latter accepts an array.

hosts:
  - foo.example.com
  - bar.example.com

Note

This matches the approach taken for accessory hosts: https://kamal-deploy.org/docs/configuration/accessories/#accessory-hosts

Edit: Example of such feedback here.

[igor-alexandrov]

I think it will be good to deprecate host and remove it in 2.1 release. No reason to support both config options.

Everything else looks great. Thank you!

[djmb]

Thanks for this @kpumuk!

We'd added support for multiple hosts in kamal-proxy before the release but hadn't had time to get them into the gem before the release of 2.0.

Just one change to pass the hosts as an array and we should be good to go 👍