[Rails6:EN] Subdomain constraint not working

[tacataca]

Hi, first of all thanks for working on updating this tutorial.

I have been trying to follow the rails 6 version and on chapter 3, when testing via the api for the first time via curl, I noticed 2 issues:

• The path is incorrect (if using the constraint), its listed as /api/v1/users/1 while it should be /users/1
• The subdomain constraint isn't working because doing something like curl http://api.localhost:3000/users/1 is invalid (unless you define api.localhost on your hosts file)

What I would suggest to be able to use the subdomain constraint on local development is:

1. Use lvh.me which resolves itself plus any subdomain to localhost (without user requiring to change anything on their system). For rails 6, you would just need to add config.hosts << "api.lvh.me" somewhere in your development.rb environment file.
   With this you can run curl http://api.lvh.me:3000/users/1
2. Alternatively add a section on editing the system hosts file.

[madeindjs]

Hi,

First of all thanks YOU for this report and your PR.

I fact this is a modification between version 5 and 6. In version 5, I setup a API host as http://api.localhost:3000/users/1. In version 6 I preferred to simplify book so I setup host URL as something like this http://localhost:3000/api/v1/users/1.

This allow me some explanation about host configuration and local environement setup who may disappoint newbies.

Setting the API under a subdomain is a good practice because it allows the application to be adapted to a DNS level. But we will simplify things for now in our case.

I corrected error directly in the book on 792a922

Thank you for this report.