Attempt to simplify the serve command for prod

[ganigeorgiev]

TL;DR: With the next release you'll be able to run on prod ./pocketbase serve example.com and this should start a HTTPS server out of the box without requiring the users to edit their /etc/hosts file when a direct mapping between the domain and the vm local network interface is missing.

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A lot of users reported issues related to the auto issued Let's encrypt certificate when using the PocketBase executable with a domain name (see #2795, #3179, #1510 (comment), #107 (comment), etc.)

The issues originate from the fact that when you have something like:

./pocketbase serve --http=example.com:80 --https=example.com:443

we currently try to bind only to the single IPv4/IPv6 address that example.com is resolving to.

This is not a problem when the domain is managed within the VPS vendor interface (eg. in Hetzner DNS Console, DigitalOcean Domains control panel, etc.), since this "mapping" between the VPS network interface and the domain is handled automatically by the vendor (most of the times).

But in some cases, users usually have to register manually an entry in their /etc/hosts file that describes the local network interface - domain relation (see #107 (comment)), which may no be always immediately clear.

This could be avoided if we listen to all local IPv4/IPv6 interfaces, aka. 0.0.0.0/[::] (most reverse proxies do the same thing). This is usually recommended/"safe" only for services that we want to be public accessible (as it is in our case when a Let's encrypt certificate is issued for a public domain). But it could also has some security implications, specifically on local dev environments with misconfigured/disabled firewall, because users may accidentally and unknowingly expose their service to the public (this is also why the default PocketBase address is 127.0.0.1:8090 and not 0.0.0.0:8090), so the default listener addresses ideally should be conditional.

With that said, in order to have a smoother out of the box deployment experience, with the next release the serve command will support domain(s) names as optional argument(s) that will auto set the default values behind the scene of the related --http and --https listener addresses. When at least one domain name argument is specified, the default flags values will be autoset to --http="0.0.0.0:80" and --https="0.0.0.0:443", otherwise - the current "safe" local dev defaults will be used (aka. --http="127.0.0.1:8090" and --https="")

For example:

./pocketbase serve example.com sub.example.com

Note that the --http and --https flags are still used and not deprecated!
They allow explicitly specifying the listener addresses and users can use them in combination with the above for example to listen to all IPv6 interfaces, instead of the default IPv4:

./pocketbase serve example.com --http="[::]:80" --https="[::]:443"

Additionally, in case the domain argument is missing, the existing behavior is preserved, aka.:

./pocketbase serve --http="example.com:80" --https="example.com:443"

would be more-or-less the same as running:

./pocketbase serve example.com --http="93.184.216.34:80" --https="93.184.216.34:443"

(93.184.216.34 is the IP of the example.com DNS A record)