REST Client – simple DSL for accessing HTTP and REST resources

A simple HTTP and REST client for Ruby, inspired by the Sinatra’s microframework style of specifying actions: get, put, post, delete.

Main page: github.com/archiloque/rest-client
Mailing list: [email protected] (send a mail to subscribe).

Usage: Raw URL

require 'rest_client'

RestClient.get 'http://example.com/resource'

RestClient.get 'http://example.com/resource', {:params => {:id => 50, 'foo' => 'bar'}}

RestClient.get 'https://user:[email protected]/private/resource', {:accept => :json}

RestClient.post 'http://example.com/resource', :param1 => 'one', :nested => { :param2 => 'two' }

RestClient.post "http://example.com/resource", { 'x' => 1 }.to_json, :content_type => :json, :accept => :json

RestClient.delete 'http://example.com/resource'

response = RestClient.get 'http://example.com/resource'
response.code
➔ 200
response.cookies
➔ {"Foo"=>"BAR", "QUUX"=>"QUUUUX"}
response.headers
➔ {:content_type=>"text/html; charset=utf-8", :cache_control=>"private" ...
response.to_str
➔ \n<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.01//EN\"\n   \"http://www.w3.org/TR/html4/strict.dtd\">\n\n<html ....

RestClient.post( url,
  {
    :transfer => {
      :path => '/foo/bar',
      :owner => 'that_guy',
      :group => 'those_guys'
    },
     :upload => {
      :file => File.new(path, 'rb')
    }
  })

Multipart

Yeah, that’s right! This does multipart sends for you!

RestClient.post '/data', :myfile => File.new("/path/to/image.jpg", 'rb')

This does two things for you:

Auto-detects that you have a File value sends it as multipart
Auto-detects the mime of the file and sets it in the HEAD of the payload for each entry

If you are sending params that do not contain a File object but the payload needs to be multipart then:

RestClient.post '/data', {:foo => 'bar', :multipart => true}

Usage: ActiveResource-Style

resource = RestClient::Resource.new 'http://example.com/resource'
resource.get

private_resource = RestClient::Resource.new 'https://example.com/private/resource', 'user', 'pass'
private_resource.put File.read('pic.jpg'), :content_type => 'image/jpg'

See RestClient::Resource module docs for details.

Usage: Resource Nesting

site = RestClient::Resource.new('http://example.com')
site['posts/1/comments'].post 'Good article.', :content_type => 'text/plain'

See RestClient::Resource docs for details.

Exceptions (see www.w3.org/Protocols/rfc2616/rfc2616-sec10.html)

for results code between 200 and 207 a RestClient::Response will be returned
for results code 301, 302 or 307 the redirection will be followed if the request is a get or a head
for result code 303 the redirection will be followed and the request transformed into a get

for other cases a RestClient::Exception holding the Response will be raised, a specific exception class will be thrown for know error codes

RestClient.get 'http://example.com/resource'
➔ RestClient::ResourceNotFound: RestClient::ResourceNotFound

begin
  RestClient.get 'http://example.com/resource'
rescue => e
  e.response
end
➔ 404 Resource Not Found | text/html 282 bytes

Result handling

A block can be passed to the RestClient method, this block will then be called with the Response. Response.return! can be called to invoke the default response’s behavior.

# Don't raise exceptions but return the response
RestClient.get('http://example.com/resource'){|response, request, result| response }
➔ 404 Resource Not Found | text/html 282 bytes

# Manage a specific error code
RestClient.get('http://my-rest-service.com/resource'){ |response, request, result, &block|
  case response.code
  when 200
    p "It worked !"
    response
  when 423
    raise SomeCustomExceptionIfYouWant
  else
    response.return!(request, result, &block)
  end
}

# Follow redirections for all request types and not only for get and head
# RFC : "If the 301, 302 or 307 status code is received in response to a request other than GET or HEAD,
#        the user agent MUST NOT automatically redirect the request unless it can be confirmed by the user,
#        since this might change the conditions under which the request was issued."
RestClient.get('http://my-rest-service.com/resource'){ |response, request, result, &block|
  if [301, 302, 307].include? response.code
    response.follow_redirection(request, result, &block)
  else
    response.return!(request, result, &block)
  end
}

Non-normalized URIs.

If you want to use non-normalized URIs, you can normalize them with the addressable gem (addressable.rubyforge.org/api/).

require 'addressable/uri'
RestClient.get(Addressable::URI.parse("http://www.詹姆斯.com/").normalize.to_str)

Lower-level access

For cases not covered by the general API, you can use the RestClient::Request class which provide a lower-level API.

You can:

specify ssl parameters
override cookies
manually handle the response (so you can operate on the response stream than reading it fully in memory)

see the class’ rdoc for more information.

Shell

The restclient shell command gives an IRB session with RestClient already loaded:

$ restclient
>> RestClient.get 'http://example.com'

Specify a URL argument for get/post/put/delete on that resource:

$ restclient http://example.com
>> put '/resource', 'data'

Add a user and password for authenticated resources:

$ restclient https://example.com user pass
>> delete '/private/resource'

Create ~/.restclient for named sessions:

sinatra:
  url: http://localhost:4567
rack:
  url: http://localhost:9292
private_site:
  url: http://example.com
  username: user
  password: pass

Then invoke:

$ restclient private_site

Use as a one-off, curl-style:

$ restclient get http://example.com/resource > output_body

$ restclient put http://example.com/resource < input_body

Logging

To enable logging you can

set RestClient.log with a ruby Logger
or set an environment variable to avoid modifying the code (in this case you can use a file name, “stdout” or “stderr”):
```
$ RESTCLIENT_LOG=stdout path/to/my/program
```

Either produces logs like this:

RestClient.get "http://some/resource"
# => 200 OK | text/html 250 bytes
RestClient.put "http://some/resource", "payload"
# => 401 Unauthorized | application/xml 340 bytes

Note that these logs are valid Ruby, so you can paste them into the restclient shell or a script to replay your sequence of rest calls.

Proxy

All calls to RestClient, including Resources, will use the proxy specified by RestClient.proxy:

RestClient.proxy = "http://proxy.example.com/"
RestClient.get "http://some/resource"
# => response from some/resource as proxied through proxy.example.com

Often the proxy url is set in an environment variable, so you can do this to use whatever proxy the system is configured to use:

RestClient.proxy = ENV['http_proxy']

Query parameters

Request objects know about query parameters and will automatically add them to the url for GET, HEAD and DELETE requests and escape the keys and values as needed:

RestClient.get 'http://example.com/resource', :params => {:foo => 'bar', :baz => 'qux'}
# will GET http://example.com/resource?foo=bar&baz=qux

Cookies

Request and Response objects know about HTTP cookies, and will automatically extract and set headers for them as needed:

response = RestClient.get 'http://example.com/action_which_sets_session_id'
response.cookies
# => {"_applicatioN_session_id" => "1234"}

response2 = RestClient.post(
  'http://localhost:3000/',
  {:param1 => "foo"},
  {:cookies => {:session_id => "1234"}}
)
# ...response body

SSL Client Certificates

RestClient::Resource.new(
  'https://example.com',
  :ssl_client_cert  =>  OpenSSL::X509::Certificate.new(File.read("cert.pem")),
  :ssl_client_key   =>  OpenSSL::PKey::RSA.new(File.read("key.pem"), "passphrase, if any"),
  :ssl_ca_file      =>  "ca_certificate.pem",
  :verify_ssl       =>  OpenSSL::SSL::VERIFY_PEER
).get

Self-signed certificates can be generated with the openssl command-line tool.

Hook

RestClient.add_before_execution_proc add a Proc to be called before each execution, it’s handy if you need a direct access to the http request.

Example:

# Add oath support using the oauth gem
require 'oauth'
access_token = ...

RestClient.add_before_execution_proc do |req, params|
  access_token.sign! req
end

RestClient.get 'http://example.com'

Need caching, more advanced logging or any ability provided by a rack middleware ?

Have a look at rest-client-components github.com/crohr/rest-client-components