This is a simple reverse proxy for Rack that pretty heavily rips off Rack Forwarder. It is not meant for production systems (although it may work), as the webserver fronting your app is generally much better at this sort of thing.
The gem is available on rubygems. Assuming you have a recent version of Rubygems you should just be able to install it via:
gem install rack-reverse-proxy
For your Gemfile use:
gem "rack-reverse-proxy", require: "rack/reverse_proxy"
Rack::ReverseProxy
should ideally be the very first middleware in your
stack. In a typical use case it is being used to proxy an entirely
different website through your application, so it's unlikely that you will want
any other middleware to modify the requests or responses. The examples below
reflect this.
require 'rack/reverse_proxy'
use Rack::ReverseProxy do
# Set :preserve_host to true globally (default is true already)
reverse_proxy_options preserve_host: true
# Forward the path /test* to https://example.com/test*
reverse_proxy '/test', 'https://example.com/'
# Forward the path /foo/* to https://example.com/bar/*
reverse_proxy /^\/foo(\/.*)$/, 'https://example.com/bar$1', username: 'name', password: 'basic_auth_secret'
end
app = proc do |env|
[ 200, {'Content-Type' => 'text/plain'}, ["b"] ]
end
run app
This example use config.middleware.insert(0
to ensure that
Rack::ReverseProxy
is first in the stack. It is possible that
other code in your app (usually in application.rb, development.rb, or production.rb)
will take over this position in the stack. To ensure
that this is not the case, view the stack by running rails middleware
. You should see
Rack::ReverseProxy
at the top. Note that
the middleware stack will likely differ slightly in each environment. All that said, it's a pretty
safe bet to put the below code into application.rb.
# config/application.rb
config.middleware.insert(0, Rack::ReverseProxy) do
reverse_proxy_options preserve_host: true
reverse_proxy '/wiki', 'https://wiki.example.com/'
end
As seen in the Rack example above, reverse_proxy
can be invoked multiple times with
different rules, which will be commulatively added.
Rules can be a regex or a string. If a regex is used, you can use the subcaptures in your forwarding url by denoting them with a $
.
Right now if more than one rule matches any given route, it throws an exception for an ambiguous match. This will probably change later. If no match is found, the call is forwarded to your application.
reverse_proxy_options
sets global options for all reverse proxies. Available options are:
:preserve_host
Set to false to omit Host headers:username
username for basic auth:password
password for basic auth:matching
is a global only option, if set to :first the first matched url will be requested (no ambigous error). Default: :all.:timeout
seconds to timout the requests:force_ssl
redirects to ssl version, if not already using it (requires:replace_response_host
). Default: false.:verify_mode
theOpenSSL::SSL
verify mode passed to Net::HTTP. Default:OpenSSL::SSL::VERIFY_PEER
.:x_forwarded_headers
sets up properX-Forwarded-*
headers. Default: true.:stripped_headers
Array of headers that should be stripped before forwarding reqeust. Default: nil. e.g.stripped_headers: ["Accept-Encoding", "Foo-Bar"]
If reverse_proxy_options
is invoked multiple times, the invocations will have a commulative effect,
only overwritting the values which they specify. Example of how this could be useful:
config.middleware.insert(0, Rack::ReverseProxy) do
reverse_proxy_options preserve_host: false
if Rails.env.production? or Rails.env.staging?
reverse_proxy_options force_ssl: true, replace_response_host: true
end
reverse_proxy /^\/blog(\/?.*)$/, 'https://blog.example.com/blog$1'
end
- Fork the project.
- Make your feature addition or bug fix.
- Add tests for it. This is important so I don't break it in a future version unintentionally.
- Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
- Send me a pull request. Bonus points for topic branches.
- Jon Swope, creator
- Oleksii Fedorov, maintainer