Support --host for Node adapter preview

[JerryWu1234]

Changes

• Closes host: true with Node adapter #6661
• Supports --host flag and/or respects server.host setting when using astro preview

Testing

Tested manually

Docs

Bug fix! We already say that the server.host setting changes astro dev and astro preview behavior.

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[bluwy]

I don't think this is the right fix, otherwise this PR makes --host only listens to one network host, instead of all available network host. Plus it gives preference to ipv4 only too. I think the issue is with the logging, and you should be able to get the information after the server starts with server.server.address() and log with that information.

[JerryWu1234]

I don't think this is the right fix, otherwise this PR makes --host only listens to one network host, instead of all available network host. Plus it gives preference to ipv4 only too. I think the issue is with the logging, and you should be able to get the information after the server starts with server.server.address() and log with that information.

server.server.address() will return an undefined.

https://github.com/wulinsheng123/astro/blob/2a33667e94ba60dd40322ad468762743dc001c15/packages/integrations/node/src/http-server.ts#L17
This host always gets undefined when we have passed --host. in nodejs adapter
https://github.com/wulinsheng123/astro/blob/2a33667e94ba60dd40322ad468762743dc001c15/packages/astro/src/core/preview/util.ts#L3
because this function only returns undefined to host.
so this createserver can't get right way

So I even pass a network address

I wanted to do like Vite https://github.com/vitejs/vite/blob/447df7cba987b30e3621076a74e2227f8232f64a/packages/vite/src/node/utils.ts#L803
But it was asynchronous to get address

[bluwy]

Sorry for the late reply. When I log before here with console.log(server.server.address()), I got this though:

> astro preview "--host"

{ address: '::', family: 'IPv6', port: 3000 }
Preview server listening on http://undefined:3000

nodejs also documented it here so I'm not sure why it isn't working. But either way I think we should still leave host undefined so the server listens on all active connections rather than a specific one. We can move the fix solely in the nodejs integration only.

Maybe we can re-implement how Vite does it here?

[JerryWu1234]

Sorry for the late reply. When I log before here with console.log(server.server.address()), I got this though:

> astro preview "--host"

{ address: '::', family: 'IPv6', port: 3000 }
Preview server listening on http://undefined:3000

nodejs also documented it here so I'm not sure why it isn't working. But either way I think we should still leave host undefined so the server listens on all active connections rather than a specific one. We can move the fix solely in the nodejs integration only.

Maybe we can re-implement how Vite does it here?

actually, I simulate the code of Vite.
Let me conclude.

1. move the code to the node adapter
2. re-implement code that got a network address

[JerryWu1234]

[JerryWu1234]

[JerryWu1234]

[JerryWu1234]

[natemoo-re]

These code changes look alright to me, but I'm not familiar enough with Node's networking logic to know for sure if this is the correct approach.

Would love @bluwy to re-review!

[natemoo-re]

Cleaned up the formatting, LGTM!

[beltonk]

astro preview "--host" is not working
npm run preview -- --host
also does not expose host