Rack: How to Store The Url as a Variable

Rack: How do you store the URL as a variable?

You shouldn't need the map part.

run Proc.new { |env|
  [
    200, 
    {
      'Content-Type'  => 'text/html', 
      'Cache-Control' => 'public, max-age=6400' 
    },
    File.open( 'archive' + env['PATH_INFO'], File::RDONLY)
  ]
}

Get the current page URL in Ruby/Rack

Since Serve uses Rack under the hood, try this in a view:

<%= request.url %>

How to setup URLs for static site with Ruby Rack on Heroku

For now I found the best answer to be:

use Rack::Static, 
  :urls => ["/media/images", "/media/js", "/media/css"],
  :root => "public"

map "/" do
  run lambda { |env|
  [
    200, 
    {
      'Content-Type'  => 'text/html', 
      'Cache-Control' => 'public, max-age=86400' 
    },
    File.open('public/index.html', File::RDONLY)
  ]
}
end

map "/portfolio" do
  run lambda { |env|
  [
    200, 
    {
      'Content-Type'  => 'text/html', 
      'Cache-Control' => 'public, max-age=86400' 
    },
    File.open('public/portfolio/index.html', File::RDONLY)
  ]
}
end

And map every URL to its respective file. Tedious, but works. See also the answer to this question regarding URL variables. Couldn't get it to work for me though.

How to generate URL with host in Rails development environment?

You could use an environment variable to configure a default host. See Luc Boissaye's answer on how to set this up with dotenv. If you don't add the .env to your repo, each developer can create his own .env and configure his (or her) own preferences.

But you can also use existing environment variables to configure the default_url_options. For example Pow.cx sets the POW_DOMAINS variable:

config.action_mailer.default_url_options = {
  ENV['POW_DOMAINS'].present? ? 'my-app.dev' : 'localhost' 
}

As far as I know you only need to set the config.action_controller.default_url_options if you want to force it to some default. When you use the rails _path helpers in your views, this will generate a relative URL (/path). If you use the _url helpers, this will generate an absolute URL (http://your.host/path), but both the protocol (http) and host (your.host) are request based.

How do I access the Rack environment from within Rails?

I'm pretty sure you can use the Rack::Request object for passing request-scope variables:

# middleware:
def call(env)
  request = Rack::Request.new(env) # no matter how many times you do 'new' you always get the same object
  request[:foo] = 'bar'
  @app.call(env)
end

# Controller:
def index
  if params[:foo] == 'bar'
    ...
  end
end

Alternatively, you can get at that "env" object directly:

# middleware:
def call(env)
  env['foo'] = 'bar'
  @app.call(env)
end

# controller:
def index
  if request.env['foo'] == 'bar'
    ...
  end
end

What is the env variable in Rack middleware?

env is just a hash. Rack itself and various middlewares add values into it.

To understand what the various keys are in the hash, check out the Rack Specification.

And here is a sample env hash:

{
  "GATEWAY_INTERFACE" => "CGI/1.1",
  "PATH_INFO" => "/index.html",
  "QUERY_STRING" => "",
  "REMOTE_ADDR" => "::1",
  "REMOTE_HOST" => "localhost",
  "REQUEST_METHOD" => "GET",
  "REQUEST_URI" => "http://localhost:3000/index.html",
  "SCRIPT_NAME" => "",
  "SERVER_NAME" => "localhost",
  "SERVER_PORT" => "3000",
  "SERVER_PROTOCOL" => "HTTP/1.1",
  "SERVER_SOFTWARE" => "WEBrick/1.3.1 (Ruby/2.0.0/2013-11-22)",
  "HTTP_HOST" => "localhost:3000",
  "HTTP_USER_AGENT" => "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:26.0) Gecko/20100101 Firefox/26.0",
  "HTTP_ACCEPT" => "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
  "HTTP_ACCEPT_LANGUAGE" => "zh-tw,zh;q=0.8,en-us;q=0.5,en;q=0.3",
  "HTTP_ACCEPT_ENCODING" => "gzip, deflate",
  "HTTP_COOKIE" => "jsonrpc.session=3iqp3ydRwFyqjcfO0GT2bzUh.bacc2786c7a81df0d0e950bec8fa1a9b1ba0bb61",
  "HTTP_CONNECTION" => "keep-alive",
  "HTTP_CACHE_CONTROL" => "max-age=0",
  "rack.version" => [1, 2],
  "rack.input" => #<StringIO:0x007fa1bce039f8>,
  "rack.errors" => #<IO:<STDERR>>,
  "rack.multithread" => true,
  "rack.multiprocess" => false,
  "rack.run_once" => false,
  "rack.url_scheme" => "http",
  "HTTP_VERSION" => "HTTP/1.1",
  "REQUEST_PATH" => "/index.html"
}

And to make it easier to use, checkout Rack::Request which makes it easier to access the values inside the env hash.

How can I route a url to a CGI script in Rack?

You can use the backticks to run the command and grab the output.

map "/check" do
  run Proc.new { |env| [200, {"Content-Type" => "text/html"}, [`./httpd/cgi-bin/check_wrapper.sh`] ] } 
end

run Rack::Directory.new("htdocs")

How do I set/get session vars in a Rack app?

session is a method that is part of some web frameworks, for example Sinatra and Rails both have session methods. Plain rack applications don’t have a session method, unless you add one yourself.

The session hash is stored in the rack env hash under the key rack.session, so you can access it like this (assuming you’ve named the rack environment to your app env):

env['rack.session'][:msg]="Hello Rack"

Alternatively, you could use Rack’s built in request object, like this:

request = Rack::Request.new(env)
request.session[:msg]="Hello Rack"

How best can I define ENV Variables in a Rack based app?

Apparently, the only problem is that I am not loading the .env.rb file inside the spec helper directory. So solving it for me was to require .env.rb file in my spec_helper.rb and it worked.

spec/spec_helper.rb

require_relative '../../.env.rb'

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