NetHttp2

NetHttp2 is an HTTP/2 client for Ruby.

Installation

Just install the gem:

$ gem install net-http2

Or add it to your Gemfile:

gem 'net-http2'

Usage

NetHttp2 can perform sync and async calls. Sync calls are very similar to the HTTP/1 calls, while async calls take advantage of the streaming properties of HTTP/2.

To perform a sync call:

require 'net-http2'

# create a client
client = NetHttp2::Client.new("http://nghttp2.org")

# send request
response = client.call(:get, '/')

# read the response
response.ok?      # => true
response.status   # => '200'
response.headers  # => {":status"=>"200"}
response.body     # => "A body"

# close the connection
client.close

To perform an async call:

require 'net-http2'

# create a client
client = NetHttp2::Client.new("http://nghttp2.org")

# prepare request
request = client.prepare_request(:get, '/')
request.on(:headers) { |headers| p headers }
request.on(:body_chunk) { |chunk| p chunk }
request.on(:close) { puts "request completed!" }

# send
client.call_async(request)

# Wait for all outgoing stream to be closed
client.join(timeout: 5)

# close the connection
client.close

Objects

NetHttp2::Client

Methods

• new(url, options={}) → NetHttp2::Client

  Returns a new client. url is a string such as http://nghttp2.org. The current options are:

  • :connect_timeout, specifies the max connect timeout in seconds (defaults to 60).
  • :ssl_context, in case the url has an https scheme and you want your SSL client to use a custom context.
  • :proxy_addr, :proxy_port, :proxy_user, :proxy_pass, specify Proxy connection parameters.

  To create a new client:

  NetHttp2::Client.new("http://nghttp2.org")

  To create a new client with a custom SSL context:

  certificate = File.read("cert.pem")
  ctx         = OpenSSL::SSL::SSLContext.new
  ctx.key     = OpenSSL::PKey::RSA.new(certificate, "cert_password")
  ctx.cert    = OpenSSL::X509::Certificate.new(certificate)
  
  NetHttp2::Client.new("https://nghttp2.org", ssl_context: ctx)

• on(event, &block)

Allows to set a callback for the client. The only available event is :error, which allows to set a callback when an error is raised at socket level, hence in the underlying socket thread.

client.on(:error) { |exception| puts "Exception has been raised: #{exception}" }

It is RECOMMENDED to set the :error callback: if none is defined, the underlying socket thread may raise an error in the main thread at unexpected execution times.

• uri → URI

  Returns the URI of the endpoint.

Blocking calls

These behave similarly to HTTP/1 calls.

• call(method, path, options={}) → NetHttp2::Response or nil

  Sends a request. Returns nil in case a timeout occurs.

  method is a symbol that specifies the :method header (:get, :post, :put, :patch, :delete, :options). The body, headers and query-string params of the request can be specified in the options, together with the timeout.

  response_1 = client.call(:get, '/path1')
  response_2 = client.call(:get, '/path2', headers: { 'x-custom' => 'custom' })
  response_3 = client.call(:post, '/path3', body: "the request body", timeout: 1)
  response_3 = client.call(:post, '/path4', params: { page: 4 })

Non-blocking calls

The real benefit of HTTP/2 is being able to receive body and header streams. Instead of buffering the whole response, you might want to react immediately upon receiving those streams. This is what non-blocking calls are for.

• prepare_request(method, path, options={}) → NetHttp2::Request

  Prepares an async request. Arguments are the same as the call method, with the difference that the :timeout option will be ignored. In an async call, you will need to write your own logic for timeouts.

  request = client.prepare_request(:get, '/path', headers: { 'x-custom-header' => 'custom' })

• call_async(request)

  Calls the server with the async request.

• join(timeout:)

  Wait for all outstanding requests to be completed, optionally with a timeout for this condition to be met. Raises NetHttp2::AsyncRequestTimeout if the timeout is reached.

NetHttp2::Request

Methods

• method → symbol

  The request's method.

• uri → URI

  The request's URI.

• path → string

  The request's path.

• params → hash

  The query string params in hash format, for example {one: 1, two: 2}. These will be encoded and appended to path.

• body → string

  The request's body.

• timeout → integer

  The request's timeout.

• on(event, &block)

  Allows to set a callback for the request. Available events are:

  • :headers: triggered when headers are received (called once).
  • :body_chunk: triggered when body chunks are received (may be called multiple times).
  • :close: triggered when the request has been completed (called once).

  Even if NetHttp2 is thread-safe, the async callbacks will be executed in a different thread, so ensure that your code in the callbacks is thread-safe.

  request.on(:headers) { |headers| p headers }
  request.on(:body_chunk) { |chunk| p chunk }
  request.on(:close) { puts "request completed!" }

NetHttp2::Response

Methods

• ok? → boolean

  Returns if the request was successful.

• headers → hash

  Returns a Hash containing the Headers of the response.

• status → string

  Returns the status code.

• body → string

  Returns the RAW body of the response.

Thread-Safety

NetHttp2 is thread-safe. However, some caution is imperative:

• The async callbacks will be executed in a different thread, so ensure that your code in the callbacks is thread-safe.
• Errors in the underlying socket loop thread will be raised in the main thread at unexpected execution times, unless you specify the :error callback on the Client (recommended).

Contributing

So you want to contribute? That's great! Please follow the guidelines below. It will make it easier to get merged in.

Before implementing a new feature, please submit a ticket to discuss what you intend to do. Your feature might already be in the works, or an alternative implementation might have already been discussed.

Do not commit to master in your fork. Provide a clean branch without merge commits. Every pull request should have its own topic branch. In this way, every additional adjustments to the original pull request might be done easily, and squashed with git rebase -i. The updated branch will be visible in the same pull request, so there will be no need to open new pull requests when there are changes to be applied.

Ensure to include proper testing. To run tests you simply have to be in the project's root directory and run:

$ rake