rack-mogilefs
If you are using Nginx you'll probably want to serve MogileFS files with the MogileFS Module, but if you need a quick way to serve them out of a Rack app, this should help.
Getting Started:
First install the gem:
gem install rack-mogilefs
There are a variety of ways to use it:
Rails 3:
# (config/routes.rb)
match "/assets/*path" => Rack::MogileFS::Endpoint.new
Rails 2:
# (app/metal/mogilefs_metal.rb)
class MogilefsMetal
def self.call(env)
if env["PATH_INFO"] =~ %r{^/assets/*}
Rack::MogileFS::Endpoint.new.call(env)
else
[ 404, { "Content-Type" => "text/html" }, ["Not Found"] ]
end
end
end
Rack middleware
# (config.ru)
use Rack::MogileFS, :path => %r{^/assets/*}
Paperclip Integration
If you are using MogileFS as a backend for Paperclip you'll want to do one of two things.
a) Set your mogilefs route to /system/*
match "/system/*path" => Rack::MogileFS::Endpoint.new
b) Change paperclip's url to match your mogilefs route, if /assets*, then:
// Rails.root/config/initializers/paperclip_mogile_url.rb
Paperclip::Attachment.default_options.merge!(:url => "/assets/:attachment/:id/:style/:filename")
File Lookup
Rack::MogileFS uses the request path (PATH_INFO) for the MogileFS key. The
content type of the file is detected by the extension, using the mime-types
gem.
If you want to customize the mapping of the PATH_INFO string to a MogileFS key you can provide a mapper proc (or anything that responds to call) like this:
# map '/assets/filename.gif' to the mogilefs key 'filename.gif'
# Rack::MogileFS and Rack::MogileFS::Endpoint take the same options
use Rack::MogileFS,
:path => %r{^/assets/*},
:mapper => lambda { |path| path.sub('/assets/', '') }
Configuration
Endpoint configuration
Here is an example of a fully customized Rack::MogileFS::Endpoint. Read the
source for more documentation.
Using the expires option is recommended, other options probably aren't needed.
Rack::MogileFS::Endpoint.new(
:default_content_type => "image/png",
:expires => 1.month, # or pass a proc...
:expires => lambda { |path, ext, mime| if mime == "images/png" ? 600 : 300 },
:client => MyMogileClient.new,
:mapper => lambda { |path| "/namespace/" + path },
:strategy => :reproxy,
:debug => false
)
Here is how I usually use it in development:
Rack::MogileFS::Endpoint.new(:expires => 1.month, :debug => true)
And production:
Rack::MogileFS::Endpoint.new(:expires => 1.month)
Client Configuration
If Rack::MogileFS detects it is inside a Rails app, it will look for a yaml
config in config/mogilefs.yml that looks like this:
development:
connection:
domain: "development.myapp.com"
hosts:
- 127.0.0.1:7001
- 127.0.0.1:7001
class: "file"
staging:
...
and initialize a MogileFS client like this:
config = YAML.load_file( Rails.root.join("config/mogilefs.yml") )[Rails.env]
MogileFS::MogileFS.new( config["connection"].symbolize_keys )
You can override this by passing in a MogileFS client of your own:
Rack::MogileFS::Endpoint.new :client => MyMogileFSClient.new
Caveats ( serving files vs reproxying )
Serving files through Ruby can be slow. Rack::MogileFS will read the entire
file into memory before sending it downstream. If you have varnish/squid/a CDN
sitting in front of rails then this isn't so problematic.
The preferred method is to set an X-Reproxy-Url header from your app and let
the web server serve the file instead of Rack::MogileFS. For Nginx, you
could have a config like this:
location /reproxy {
internal;
set $reproxy $upstream_http_x_reproxy_url;
proxy_pass $reproxy;
proxy_hide_header Content-Type;
}
For Apache, there is mod_reproxy
Rack::MogileFS will use this method if you pass a strategy option of :reproxy
use Rack::MogileFS, :strategy => :reproxy
Rack::MogileFS will look up the internal urls for the file, and set two
headers to reproxy the request:
X-Accel-Redirect: /reproxy
X-Reproxy-Url: http://internal.ip/path/to/mogile/file.fid
You'll have to make sure your web server knows how to handle this request.