How do I configure the hostname for Rails ActionMailer?

Question

I'm working on a fairly traditional forgot password email - I want to email the user a password change token embedded in a link that they can click on in order to change their password. I'm emailing via the traditional ActionMailer.

If I use a normal link_to tag

<%= link_to "click here", :controller => foo, :action => 'bar', :token => token %>

I get a relative link - rather useless from an email.

If I add in

:only_path => false, then it errors saying I need to set default_url_options[:host]. The ActionController docs imply that you do that by overriding the #default_url_options methods in your controller. Surely there's a configuration option to tell Rails what it's hostname is without adding my own config file, parsing it, etc?

Solution 1

default_url_options is available from config.action_mailer and should be set in your environment's configuration file.

For example, in config/environments/production.rb:

config.action_mailer.default_url_options = {
  :host => 'www.yourdomain.com'
}

For local testing, modify config/environments/development.rb:

config.action_mailer.default_url_options = {
  :host => '127.0.0.1',
  :port => 3000
}

Then, assuming you have a named route called forgot_password_login, you can generate the login link URL in your mailer using something like this:

forgot_password_login_url(:token => 'a7s8q15sk2...')

Solution 2

You probably want to set :protocol => 'https' as well, btw.

config.action_mailer.default_url_options = { 
    :host => "portal.example.com", 
    :protocol => 'https' 
}

Solution 3

There is another alternative, as described in http://pivotallabs.com/how-i-leaned-to-stop-hating-and-love-action-mailer/

This solution has the advantage that it doesn't require any configuration (so less of a hassle), and works fine as long as you send emails from within controllers.

But if you plan on sending email without going through a controller (e.g. from command line or in response to another email), you need the static configuration.

Comments

[Sam Saffron]

+1 for both the question and answer, this is so weird ... why is this setting on action mailer?

[Pascal]

When sending an email, then there is no HTTP Request to take these values from.

[John Douthat]

request isn't available from within a mailer

[Mohsen Rashidi]

Exactly. I could pass it as one of the parameters to the email generation - but we just decided to move this particular email to being sent from our Application Server instead of the web front-end. I think that means I need to make that custom config file that has the URL of the frontend website in it.

[Rob Di Marco]

doh, missed the mailer part of it

[Mohsen Rashidi]

That's a good tip, though I'm afraid I need the static configuration. For some reason, I keep running into more and more processing that needs to happen outside of a web hit.

[Kevin]

Thanks for the :protocol => 'https' pointer. using 'portal.example.com' does not seem to work properly, at least with Devise mailers. The resulting urls begin with 'example.com' regardless of the subdomain).

[riley chen]

current link. pivotallabs.com/…

[engineerDave]

not you have a "hanging" comma in your default_url_options hash. I would edit it but its a 1 char edit which is verboten on SO.

[Noah Passalacqua]

I feel like im losing my mind. This is not working for me