Subdomains and locally installed Rails app - ruby-on-rails

Question

I can't figure out what I'm overlooking, perhaps it's obvious or lack of understanding.
The app I'm working with uses subdomains which on the hosting server work properly. I figured locally installing would kick up some issues around routing, so I read up on making changes to /etc/hosts and using the Ghost gem. Both seem to work fine i.e. localhost:3000/ becomes myapp.local:3000 but I don't understand how to go about logging into a subdomain account. Here's an example...
myapp.local:3000/session/new = the default login page for the app
myapp.local:3000/signup = default signup page
I can create an account here e.g. Sub1
The thank you page is shown w/ the reference to sub1.myapp.com which points to the hosted app (the local db shows this domain as well)
sub1.myapp.local manually added to /etc/hosts and dscacheutil -flushcache
sub1.myapp.local:3000/session/new is the subdomain
login attempts return that this isn't a valid domain. This seems to make sense because the local db shows the url as sub1.myapp.com on the hosting server.
So my question is whether there's a local workaround that I can use for development or have I totally missed a fundamental concept along the way?

Answer 1

you might just want to try putting the actual dot com in your /etc/hosts file.
ie:
127.0.0.1 sub1.myapp.com
127.0.0.1 myapp.com
127.0.0.1 anyothersubdomains.myapp.com
what this usually does is trick your computer into thinking it is the host of all of those, so you can't go to the real site anymore in a web browser.
if you do want it to be .local, presumably so that you can refer to the real online site while working on a local copy, you should probably take a look in app/controllers/application_controller.rb (sometimes application.rb) and look for logic in there that helps determine what to do depending on the subdomain. maybe its hard coded to only look for a .com or something.

Answer 2

If you are using the webrick server or something like Puma for development you can use lvh.me to access your subdomains. e.g.
http://sub.lvh.me:3000/
http://lvh.me:3000/ is equal http://localhost:3000/