--hmr-host is not available

[ranisalt]

🐛 bug report

I'm trying to configure the host that hot module replacement responds, since I am developing in a remote machine but accessing from local browser.

🎛 Configuration (.babelrc, package.json, cli command)

Zero configuration

🤔 Expected Behavior

Running parcel serve ... --host 0.0.0.0 --hot-host 12.34.56.78 should make the hot module replacement connect to the socket in wss://12.34.56.78:1234 instead of wss://127.0.0.1:1234 or wss://0.0.0.0:1234

😯 Current Behavior

It errors with

error: unknown option '--hot-host'

Even if prepending --hot it does not work:

error: unknown option '--hot-host'

However, the README states those flags exist, and I see that HMRRuntime.js tries to use these. I assume that --hot-port will also not work.

🌍 Your Environment

Software	Version(s)
Parcel	v2.0.0-nightly.429
Node	v14.12.0
npm/Yarn	v1.22.5
Operating System	Ubuntu 20.04.1 LTS

[mischnic]

--hmr-port does exist (though it's not listed on https://v2.parceljs.org/features/cli/#parameters-related-to-the-dev-server%2Fwatch-mode-(serve-and-watch) ) and parcel serve --help also lists it 😉 :

parcel/packages/core/parcel/src/cli.js

Line 101 in 296bc57

'--hmr-port <port>': 'hot module replacement port',

Looks like --hmr-host isn't exposed in the CLI...

[ranisalt]

I didn't know about serve --help, I always resorted to the README/website 😆

Edit: there's another mistake, --host describes as "defaults to listening on all interfaces" but actually by default it only listens to loopback (localhost).

[nextlogic-ono]

I agree it needs --hmr-host.

I'm running parcel behind a reverse proxy of another host, so specifying --host as the exposed host will fail saying that it cannot bind to that IP address.

What would work is the host for binding should be different from the host that parcel connects to from the browser.

Also,
parcel watch --host 127.0.0.1
doesn't work as it still keeps on listening to all the interfaces as I assumed this will change the IP it binds to according to the documentation.

Ideally,
parcel watch --host 127.0.0.1 --hmr-host wss://host.browser.connects.to:443
would make parcel listen to 127.0.0.1 while the browser connects to wss://host.browser.connects.to:443 with its HMR.
(I'm specifying the full URL, since it implies even though parcel is running without https locally, the exposed reverse proxy host has ssl termination and needs to be connected with https. Perhaps --hmr-connect would be a better name.)

[remotezygote]

The above PR should satisfy this issue for closing.

[nextlogic-ono]

It's not handling the issue of using a different port by the example I posted above by sharing the port the hmr listens to and the port the browser connects to.

[remotezygote]

Does #8137 help?

[nextlogic-ono]

Does #8137 help?

Yes, sorry missed about 8137.