You can mount your Tumblr Blog to your existing Rails app. Forked from: https://gist.github.com/petewarden/3950261

blog_controller.rb

class BlogController < ApplicationController
  def index
    path = params[:path].to_s
    source_url = 'http://yourblog.tumblr.com/' + path
    source_content_type = ''
    source_body = open(source_url) do |f|
      source_content_type = f.content_type     # "text/html"
      f.read
    end
    if source_content_type == 'text/html'
      output_base = request.base_url + '/blog'
      output_body = source_body.gsub(/\b(href|src|rel)="\/\//, '\1="https:\/\/')
      output_body = output_body.gsub(/\b(href|src|rel)="\//, '\1="' + output_base + '/')
      output_body = output_body.gsub(/\b(href|src|rel)="http:\/\/yourblog\.tumblr\.com/, '\1="/blog')
    else
      output_body = source_body
    end
    
    render :text => output_body, :content_type => source_content_type, :layout => false
  end
end

routes.rb

YourApp::Application.routes.draw do
  get "/blog" => "blog#index"
  get "/blog/*path" => "blog#index"
  
end