Initial commit

.gitignore

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+/Gemfile.lock
+/pkg
+/test/serve
+.DS_Store

.rubocop.yml

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+AllCops:
+    TargetRubyVersion: 2.3
+
+Style/ClassAndModuleChildren:
+    Enabled: false
+
+Style/Documentation:
+    Enabled: false
+
+Style/TrailingCommaInLiteral:
+    EnforcedStyleForMultiline: comma
+
+Style/TrailingCommaInArguments:
+    EnforcedStyleForMultiline: comma
+
+Style/NumericPredicate:
+    Enabled: false
+
+Style/ZeroLengthPredicate:
+    Enabled: false
+
+Metrics/BlockLength:
+    Enabled: false
+
+Metrics/MethodLength:
+    Enabled: false
+
+Metrics/AbcSize:
+    Enabled: false
+
+Metrics/CyclomaticComplexity:
+    Enabled: false

Gemfile

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+# frozen_string_literal: true
+
+source 'https://rubygems.org'
+
+gemspec

LICENSE

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+BSD 3-Clause License
+
+Copyright (c) 2017, Loic Nageleisen
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of the copyright holder nor the names of its
+  contributors may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Rakefile

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+require 'rake/testtask'
+require 'bundler'
+
+Bundler::GemHelper.install_tasks
+
+Rake::TestTask.new do |t|
+  t.libs << 'test'
+  t.test_files = FileList['test/test_*.rb']
+  t.verbose = true
+end

lib/nanoserve.rb

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+# frozen_string_literal: true
+
+require 'socket'
+require 'logger'
+require 'time'
+
+module NanoServe
+  class TCPResponder
+    def initialize(host, port, &block)
+      @host  = host
+      @port  = port
+      @block = block
+      @thr   = nil
+    end
+
+    def start(y)
+      server = TCPServer.new(@port)
+
+      @thr = Thread.new do
+        Thread.abort_on_exception = true
+        conn = server.accept
+        port, host = conn.peeraddr[1, 2]
+        client = "#{host}:#{port}"
+        logger.debug "#{client}: connected"
+
+        begin
+          @block.call(conn, y)
+        rescue EOFError
+          logger.debug "#{client}: disconnected"
+        ensure
+          logger.debug "#{client}: closed"
+          conn.close
+        end
+      end
+
+      return unless block_given?
+
+      yield
+
+      @thr.join
+      server.close
+
+      y
+    end
+
+    def stop
+      @thr.kill
+    end
+
+    def logger
+      @logger ||= Logger.new(STDOUT).tap { |l| l.level = Logger::INFO }
+    end
+  end
+
+  class HTTPResponder < TCPResponder
+    def initialize(host, port)
+      super(host, port) do |conn, y|
+        req = Request.new
+        buf = +''
+        loop do
+          line = conn.readline
+          break if line.chomp == ''
+          req << line
+          buf << line
+        end
+        logger.debug "request:\n" + buf.gsub(/^/, '    ')
+
+        res = Response.new
+        logger.debug 'calling'
+        yield(res, req, y)
+        logger.debug "response:\n" + res.to_s.gsub(/^/, '    ')
+        conn.write(res.to_s)
+      end
+    end
+
+    class RequestError < StandardError; end
+
+    class Request
+      def initialize
+        @method       = nil
+        @uri          = nil
+        @http_version = nil
+        @sep          = nil
+        @headers      = {}
+      end
+
+      def params
+        Hash[*@uri.query.split('&').map { |kv| kv.split('=') }.flatten]
+      end
+
+      def <<(line)
+        if @method.nil?
+          parse_request(line.chomp)
+        elsif @sep.nil?
+          parse_header(line.chomp)
+        else
+          @body << line
+        end
+      end
+
+      REQ_RE = %r{(?<method>[A-Z]+)\s+(?<path>\S+)\s+(?<version>HTTP/\d+.\d+)$}
+
+      def parse_request(str)
+        unless (m = str.match(REQ_RE))
+          raise RequestError, "cannot parse request: '#{str}'"
+        end
+
+        @method       = parse_method(m[:method])
+        @uri          = parse_path(m[:path])
+        @http_version = parse_version(m[:version])
+      end
+
+      def parse_method(str)
+        str
+      end
+
+      def parse_path(str)
+        URI(str)
+      end
+
+      def parse_version(str)
+        str
+      end
+
+      def parse_header(str)
+        (@sep = '' && return) if str == ''
+
+        unless (m = str.match(/(?<header>[A-Z][-A-Za-z]*):\s+(?<value>.+)$/))
+          raise RequestError, "cannot parse header: '#{str}'"
+        end
+
+        @headers[m[:header]] = m[:value]
+      end
+    end
+
+    class Response
+      def headers
+        {
+          'Date'             => date,
+          'Content-Type'     => content_type,
+          'Content-Length'   => content_length,
+          'Last-Modified'    => last_modified,
+          'Server'           => server,
+          'ETag'             => etag,
+          'Connection'       => connection,
+        }
+      end
+
+      def body
+        @body ||= ''
+      end
+
+      def body=(value)
+        @body = value.tap { @content_length = body.bytes.count.to_s }
+      end
+
+      def to_s
+        (status_line + header_block + body_block).encode('ASCII-8BIT')
+      end
+
+      private
+
+      def status_code
+        200
+      end
+
+      def status_string
+        'OK'
+      end
+
+      def status_line
+        "HTTP/1.1 #{status_code} #{status_string}\r\n"
+      end
+
+      def header_block
+        headers.map { |k, v| [k, v].join(': ') }.join("\r\n") + "\r\n\r\n"
+      end
+
+      def body_block
+        body
+      end
+
+      def content_length
+        @content_length ||= body.bytes.count.to_s
+      end
+
+      def content_type
+        @content_type ||= 'text/html; charset=UTF-8'
+      end
+
+      def date
+        @date ||= Time.now.httpdate
+      end
+
+      def last_modified
+        @last_modified ||= date
+      end
+
+      def etag
+        @etag ||= SecureRandom.uuid
+      end
+
+      def server
+        'NanoServe'
+      end
+
+      def connection
+        'close'
+      end
+    end
+  end
+end

nanoserve.gemspec

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+# frozen_string_literal: true
+
+Gem::Specification.new do |s|
+  s.name        =  'nanoserve'
+  s.version     =  '0.1.0'
+  s.licenses    =  ['3BSD']
+  s.summary     =  'Listen to one-shot connections'
+  s.authors     =  ['Loic Nageleisen']
+  s.email       =  'loic.nageleisen@gmail.com'
+  s.files       =  Dir['lib/**/*.rb'] + Dir['bin/*']
+  s.files      +=  Dir['[A-Z]*'] + Dir['test/**/*']
+  s.description =  <<-EOT
+    NanoServe allows you to wait for an external call and act on it.
+  EOT
+
+  s.required_ruby_version = '>= 2.3'
+
+  s.add_development_dependency 'minitest', '~> 5.10'
+  s.add_development_dependency 'pry'
+  s.add_development_dependency 'rake', '~> 12.0'
+end

test/test_nanoserve.rb

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+# frozen_string_literal: true
+
+require 'minitest/autorun'
+require 'nanoserve'
+
+require 'securerandom'
+require 'uri'
+require 'net/http'
+require 'pry'
+require 'pathname'
+
+class TestNanoServe < MiniTest::Test
+  def test_tcp_responder
+    uuid = SecureRandom.uuid.encode('UTF-8')
+    uri = URI('tcp://localhost:2000')
+
+    r = NanoServe::TCPResponder.new(uri.host, uri.port) do |conn, buf|
+      buf << conn.readpartial(1024)
+    end
+
+    buf = r.start(+'') do
+      s = TCPSocket.new(uri.host, uri.port)
+      s.write(uuid)
+      s.close
+    end
+
+    assert_equal(uuid, buf)
+  end
+
+  def test_http_responder
+    uuid = SecureRandom.uuid.encode('UTF-8')
+    uri = URI('http://localhost:2000')
+
+    r = NanoServe::HTTPResponder.new(uri.host, uri.port) do |res, req, y|
+      y << req
+
+      res.body = <<-EOS.gsub(/^ {8}/, '')
+        <html>
+        <head>
+          <title>An Example Page</title>
+        </head>
+        <body>
+          Hello World, this is a very simple HTML document.
+        </body>
+        </html>
+      EOS
+    end
+
+    req = r.start([]) do
+      Net::HTTP.get(uri + "test?uuid=#{uuid}")
+    end
+
+    assert_equal(uuid, req.first.params['uuid'])
+  end
+end