Hostname configuration for DNS domain name

[alxlion]

Improve documentation about domain configuration + fix error:

[error] Could not check origin for Phoenix.Socket transport.

Origin of the request: https://clapper.some.domain/

This happens when you are attempting a socket connection to a different host than the one configured in your config/files.

For example, in development the host is configuredto "localhost" but you may be trying to access it from"127.0.0.1".

To fix this issue, you may either:

1. update [url: [host: ...]] to your actual host in the config file for your current environment (recommended)

2. pass the :check_origin option when configuring your endpoint or when configuring the transport in your UserSocket module, explicitly outlining which origins are allowed: check_origin: ["https://example.com", "//another.com:888", "[//other.com](https://other.com/)"]

[railsmechanic]

Hi @alexlionco
I think you need to set the environment variable ENDPOINT_HOST and ENDPOINT_PORT.
For me it works with ENDPOINT_HOST=claper.<your-domain.com> and ENDPOINT_PORT=<80/443>.