# When do you use initializer vs environments/\*.rb

**URL:** <https://www.ruby-forum.com/t/when-do-you-use-initializer-vs-environments-rb/133264>\
**Category:** Rails\
**Created:** [March 29, 2008, 3:19pm UTC](https://www.ruby-forum.com/t/when-do-you-use-initializer-vs-environments-rb/133264 "2008-03-29T15:19:56Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![frank\_programmer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/958977/32.png) [@frank\_programmer](https://www.ruby-forum.com/u/frank_programmer)\
**Post date:** [March 29, 2008, 3:19pm UTC](https://www.ruby-forum.com/t/when-do-you-use-initializer-vs-environments-rb/133264/1 "2008-03-29T15:19:56Z")

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Hi,

I am setting up my smtp settings. In the past I would put them in  
config/environments/development.rb for my development environment and  
config/environments/production.rb for my production envrionment.

However Rails 2.0 seems to be encouraging people to create their own  
initializers, such as mail.rb, under config/initializers. Is it  
better to do it this way? If I do it that way how do I differentiate  
envrionments?

–  
Frank K.

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**Author:** ![frank\_programmer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/958977/32.png) [@frank\_programmer](https://www.ruby-forum.com/u/frank_programmer)\
**Post date:** [March 31, 2008, 8:29am UTC](https://www.ruby-forum.com/t/when-do-you-use-initializer-vs-environments-rb/133264/2 "2008-03-31T08:29:18Z")

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I’m no expert, but I think initializers are only to keep your  
environment.rb file clean, and you can’t differentiate between  
environments.

That’s what I’m inferring from  
[http://ryandaigle.com/articles/2007/2/23/what-s-new-in-edge-rails-stop-littering-your-evnrionment-rb-with-custom-initializations](http://ryandaigle.com/articles/2007/2/23/what-s-new-in-edge-rails-stop-littering-your-evnrionment-rb-with-custom-initializations)

---

<div class="post-metadata">

**Author:** ![frank\_programmer](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/958977/32.png) [@frank\_programmer](https://www.ruby-forum.com/u/frank_programmer)\
**Post date:** [March 31, 2008, 10:21am UTC](https://www.ruby-forum.com/t/when-do-you-use-initializer-vs-environments-rb/133264/3 "2008-03-31T10:21:09Z")

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On 31 Mar 2008, at 08:29, Mike Nicholaides wrote:

> I’m no expert, but I think initializers are only to keep your  
> environment.rb file clean, and you can’t differentiate between  
> environments.

Well… you can. What you can’t do, is use different files for a  
different environment. The files in initializers are “appended” to the  
general environment.rb if you will. That means you can still use  
conditional rails environment detection (if RAILS\_ENV==“production”).

Another big advantage of the initializers to us is capistrano  
deployment. We have a certain application that needs to be rolled out  
to several private customer servers, each with their own settings  
(e.g. SMTP server for one customer, sendmail for another, …). In the  
past, we’d have to keep a different environment.rb file for each  
customer, even if 90% of all data in there was exactly the same. With  
the initializers, we can just write away a custom configuration if  
there’s a need.

> That’s what I’m inferring from  
> [http://ryandaigle.com/articles/2007/2/23/what-s-new-in-edge-rails-stop-littering-your-evnrionment-rb-with-custom-initializations](http://ryandaigle.com/articles/2007/2/23/what-s-new-in-edge-rails-stop-littering-your-evnrionment-rb-with-custom-initializations)

Best regards

Peter De Berdt