yorickpeterse/env_madness.md

## env_madness.md

      
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              env_madness.md
            
          
    This Gist aims to get some discussion going and throw some ideas around about
introducing a more universal way to configure the environment/mode of Ruby
applications and libraries (where applicable).
When speaking about the environment/mode (referred to as "environment" from
this point on) we're speaking about the variable/option that specifies a
alternative set of configuration options to use. That is, separate database
options, hostnames and so on. A basic example of this is the standard Rails
database configuration file:
development:
  adapter: sqlite3
  database: db/development.sqlite3
  pool: 5
  timeout: 5000

test:
  adapter: sqlite3
  database: db/test.sqlite3
  pool: 5
  timeout: 5000

production:
  adapter: sqlite3
  database: db/production.sqlite3
  pool: 5
  timeout: 5000
Currently different frameworks/libraries use different environment variable
names to change the application's environment (sometimes also providing CLI
options for this). For example, Rack uses RACK_ENV, Rails uses both
RACK_ENV and RAILS_ENV (I think), daemon-kit uses
DAEMON_ENV. There are the ones that I can think of, I would not be surprised
if there are more out there.
What I, and probably others would like to see is a universal environment
variable that can be used to set the application's environment. That is, all
frameworks (or at least the ones that are willing to) would respond to the same
variable. Doing so would simplify configuration management as one no longer has
to set a handful of variables to achieve something that should be trivial.
I asked a few noteworthy project owners/maintainers about their opinion in the
following Tweet: https://twitter.com/YorickPeterse/status/437948328420990976.
Some of the proposed variable names from this are as following:

RUBY_ENV
ENV
RUBY_MODE

To me personally the name does not matter that much, though I think ENV could
potentially collide with non Ruby related settings. As such I'd like to receive
feedback from those that are interested so we can come up with a mutually
agreed upon standard.