EzClient  

EzClient is HTTP gem wrapper for easy persistent connections and more.

Installation

Add this line to your application's Gemfile:

gem "ezclient"

Usage

url = "http://example.com"

client_options = { timeout: 10 }
client = EzClient.new(client_options) # => EzClient::Client object

request_options = { params: { a: 1 } }
request = client.request(:get, url, request_options) # => EzClient::Request object

# Performs a GET request to https://example.com/?a=1
response = request.perform # => EzClient::Response object

# Same request but will raise EzClient::ResponseStatusError in case of 4xx or 5xx response code
response = request.perform!

# Alternatively, you can just do:
response = client.perform!(:get, url, request_options) # => EzClient::Response object

Valid client options are:

• api_auth – arguments for ApiAuth.sign! (see https://github.com/mgomes/api_auth)
• basic_auth – arguments for basic authentication (either a hash with :user and :pass keys or a two-element array)
• cookies – a hash of cookies (or HTTP::CookieJar object) for requests
• headers – a hash of headers for requests
• keep_alive – timeout for persistent connection in seconds
• max_retries – maximum number of retries in case retry_exceptions option is provided
• on_complete – callback called on request completion
• on_error – callback called on request exception
• on_retry – callback called on request retry
• retry_exceptions – an array of exception classes to retry
• ssl_context – ssl context for requests (an OpenSSL::SSL::SSLContext instance)
• timeout – timeout for requests in seconds or hash like { read: 5, write: 5, connect: 1 }
• follow – enable following redirects (true or hash with options – e.g. { max_hops: 1, strict: false})
• error_wrapper – callback called on request exception, makes it possible to handle any error, default behavior: raise error

All these options are passed to each request made by this client but can be overriden on per-request basis.

Extra per-request only options are:

• body – raw request body
• form – hash for urlencoded body
• json – data for json (also adds application/json content-type header)
• metadata – metadata for request (passed in callbacks)
• params – becomes query for GET and form for other requests
• query – hash for uri query

Persistent connections

If you provide keep_alive option to the client or particular request, the connection will be stored in the client and then reused for all following requests to the same origin within specified amount of time.

Note that if you are using persistent connections, you shouldn't store your client in a variable that is accessable by different threads. See the example:

module MyApp
  # Bad: multiple threads will use the same socket
  def self.bad_client
    @ezclient ||= EzClient.new(keep_alive: 100)
  end

  # Good: each thread has it's own socket
  def self.good_client
    Thread.current[:ezclient] ||= EzClient.new(keep_alive: 100)
  end
end

Alose note that, as of now, EzClient will automatically retry the request on any HTTP::ConnectionError exception in this case which may possibly result in two requests received by a server (see httprb/http#459).

Callbacks and retrying

You can provide on_complete, on_error and on_retry callbacks like this:

on_complete = -> (request, response, metadata) { ... }
on_error = -> (request, error, metadata) { ... }
on_retry = -> (request, error, metadata) { ... }
error_wrapper = -> (request, error, metadata) { raise error }

client = EzClient.new(
  on_complete: on_complete,
  on_error: on_error,
  on_retry: on_retry,
  retry_exceptions: [StandardError],
  max_retries: 2,
  error_wrapper: error_wrapper
)

response = client.perform!(:get, url, metadata: :hello)

The arguments passed into callbacks are:

• request – an EzClient::Request instance
• response – an EzClient::Response instance
• error – an exception instance
• metadata - the metadata option passed into a request

Request object

request = client.request(:post, "http://example.com", json: { a: 1 }, timeout: 15)

request.verb # => "POST"
request.url # => "http://example.com"
request.body # => '{"a": 1}'
request.headers # => { "Content-Type" => "application/json; charset=UTF-8", ... }
request.elapsed_seconds # => 0.08117745001072763

Response object

response = request.perform(...)

response.body # => String
response.headers # => Hash
response.code # => Integer

response.ok? # Returns if request was 2xx status
response.redirect? # Returns if request was 3xx status
response.client_error? # Returns if request was 4xx status
response.server_error? # Returns if request was 5xx status
response.error? # Returns if request was 4xx or 5xx status

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/umbrellio/ezclient.

License

Released under MIT License.

Authors

Created by Yuri Smirnov.