Running same Ruby application in multiple environments - ruby-on-rails

Question

I'm doing local development of a Ruby application, and want to setup both a production and development environment. I intend to use production locally almost like a staging server, to demonstrate the current state of the codebase to my client. However, I want to run an actual development environment with different settings for my personal use.
I intend to use virtual hosts to distinguish the two sites. No matter how I try to change settings in Apache + Passenger, they both run in the same environment though (either both production or both development). How can I make the same codebase run in different environments for different virtual hosts?
/etc/apache2/sites-available/app.conf:
<VirtualHost *:80>
ServerName app.local
ServerAlias app.example.com
DocumentRoot /code/sites/app/public
RailsEnv production
RackEnv production
# Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
# error, crit, alert, emerg.
LogLevel debug ssl:debug
ErrorLog ${APACHE_LOG_DIR}/app.error.log
CustomLog ${APACHE_LOG_DIR}/app.access.log combined
</VirtualHost>
/etc/apache2/sites-available/app-dev.conf:
<VirtualHost *:80>
ServerName app.dev.local
DocumentRoot /code/sites/app_dev/public
RailsEnv development
RackEnv development
# Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
# error, crit, alert, emerg.
LogLevel debug ssl:debug
ErrorLog ${APACHE_LOG_DIR}/app-dev.error.log
CustomLog ${APACHE_LOG_DIR}/app-dev.access.log combined
</VirtualHost>

Answer 1

Give each app vhost a different PassengerAppGroupName so that Phusion Passenger treats them as different apps.

Answer 2

This is a much easier solution to your problem. https://ngrok.com/ It won't run as fast as it would if you set everything up, but it's infinitely easier to set up.