Fix default host

[romanlex]

Default host is 0.0.0.0 by doc

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[fivethreeo]

I think update docs instead of the code.

[romanlex]

@fivethreeo ok, done

[gregmartyn]

0.0.0.0 is not localhost. Localhost is 127.0.0.1; 0.0.0.0 is INADDR_ANY. The difference is that 0.0.0.0 listens on all network adapters, but 127.0.0.1 only listens for machine-local connections.

If you're running your site in a container/vm, your host will only be able to connect to the container if the container is listening on 0.0.0.0 and a port forward has been set up. If the container is listening on 127.0.0.1, it won't be able to connect -- only connections from the container itself can connect to it.

If you're not running inside a VM, using 127.0.0.1 is a little like having a firewall: other computers on your network won't be able to connect to it no matter what. 0.0.0.0 would allow those connections if you don't have a firewall configured.

More info: https://superuser.com/questions/949428/whats-the-difference-between-127-0-0-1-and-0-0-0-0

[romanlex]

@gregmartyn it's pr changes only md files for consistency

[gregmartyn]

I don't see how it's making it consistent though. Razzle listens on 0.0.0.0 by default as far as I can tell.

https://github.com/jaredpalmer/razzle/blob/master/packages/create-razzle-app/templates/default/src/index.js
does

express()
    .listen(port, function(err) {

which is https://expressjs.com/en/api.html#app.listen
which is https://nodejs.org/api/http.html#http_server_listen
which is https://nodejs.org/api/net.html#serverlistenport-host-backlog-callback
which says:
If host is omitted, the server will accept connections on the unspecified IPv6 address (::) when IPv6 is available, or the unspecified IPv4 address (0.0.0.0) otherwise.

In most operating systems, listening to the unspecified IPv6 address (::) may cause the net.Server to also listen on the unspecified IPv4 address (0.0.0.0).

[gregmartyn]

Oh I see what you mean. Sorry!

devServer uses HOST here https://github.com/jaredpalmer/razzle/blob/master/packages/razzle/config/createConfigAsync.js#L854
for the port 3001 listener (aka PORT_DEV)
and on line 138 when CLIENT_PUBLIC_PATH wasn't set.

So we have a problem. HOST isn't being used by the prod server, but probably should be. A default of 0.0.0.0 would make sense for that, especially for backward compatibility. Otherwise you can't choose which network interface the production server listens on, which could be a problem if you want to have different services listening on different interfaces but the same port.

The dev server is defaulting to 127.0.0.1 for the PORT_DEV client-side build but the docs say 0.0.0.0. (The server-side build on PORT behaves the same as the prod build above) 127.0.0.1 makes sense as a safe default, but then it'd conflict with the new prod server default of 0.0.0.0. Further, the CLIENT_PUBLIC_PATH fallback is treating HOST as a routable address, but that wouldn't work for HOST=0.0.0.0.

Sounds to me like a separate var is in order. HOST_DEV (consistent with PORT_DEV, which already exists), defaulting to 127.0.0.1. What do y'all think?

[fivethreeo]

As long as it describes the behaviour it is all ok.

btw. I am close to stopping razzle development unless someone shares in the development. Considering just using next or plain webpack.

[romanlex]

Next.js dictates how to organize a project ( routes example

[sergeysova]

Hi!
How can I help you maintaining this project?
I think razzle is awesome, and I choose it again and again over Remix or Nextjs.

Thank you, for your work!

Original: #1159 (comment)