From d4612d9db09a99b878eeecb9e710ed5a170cb63f Mon Sep 17 00:00:00 2001
From: David Lee <davidomundo@gmail.com>
Date: Fri, 27 Feb 2015 02:43:00 -0800
Subject: [PATCH 1/4] Support subdomain and paths in process labels

---
 lib/invoker/dns_cache.rb                   | 58 ++++++++++++++++++++--
 lib/invoker/ipc/dns_check_command.rb       |  7 +--
 lib/invoker/ipc/message.rb                 |  2 +-
 lib/invoker/power/balancer.rb              | 19 ++++---
 lib/invoker/power/http_parser.rb           | 11 ++++
 spec/invoker/config_spec.rb                |  2 +-
 spec/invoker/ipc/dns_check_command_spec.rb |  8 +--
 spec/invoker/power/balancer_spec.rb        |  4 +-
 spec/invoker/power/http_parser_spec.rb     | 10 ++++
 9 files changed, 96 insertions(+), 25 deletions(-)

diff --git a/lib/invoker/dns_cache.rb b/lib/invoker/dns_cache.rb
index 1ca0069..e213dc7 100644
--- a/lib/invoker/dns_cache.rb
+++ b/lib/invoker/dns_cache.rb
@@ -2,22 +2,70 @@ module Invoker
   class DNSCache
     attr_accessor :dns_data
 
+    # INI:
+    # [www.app]
+    # port = 8000
+    #
+    # [www.app/chat]
+    # port = 8001
+    #
+    # [app]
+    # port = 8002
+    #
+    # [app/api]
+    # port = 8003
+    #
+    # dns_data:
+    # {
+    #   'www.app' => [
+    #     ['/', 8000],
+    #     ['/chat', 8001]
+    #   ],
+    #   'app' => [
+    #     ['/', 8002],
+    #     ['/api, 8003]
+    #   ]
+    # }
     def initialize(config)
-      self.dns_data = {}
+      self.dns_data = Hash.new {|h,k| h[k] = []}
       @dns_mutex = Mutex.new
       Invoker.config.processes.each do |process|
         if process.port
-          dns_data[process.label] = { 'port' => process.port }
+          add(process.label, process.port)
         end
       end
     end
 
-    def [](process_name)
-      @dns_mutex.synchronize { dns_data[process_name] }
+    def find_process(host, path)
+      @dns_mutex.synchronize {
+        until dns_data.include?(host) || host.nil?
+          host = host.split('.', 2)[1]
+        end
+
+        dns_data[host].reverse_each {|prefix, label, port|
+          if path_matches_prefix?(path, prefix)
+            return {:process_name => label, :port => port}
+          end
+        }
+
+        nil
+      }
     end
 
     def add(name, port)
-      @dns_mutex.synchronize { dns_data[name] = { 'port' => port } }
+      @dns_mutex.synchronize {
+        host, path_prefix = split_host_path(name)
+        (dns_data[host] << [path_prefix.to_s, name, port]).sort!
+      }
+    end
+
+    private
+    def split_host_path(label)
+      label.split(%r{(?=/)}, 2)
+    end
+
+    def path_matches_prefix?(path, prefix)
+      path == prefix || path.start_with?(prefix + '/')
     end
   end
 end
diff --git a/lib/invoker/ipc/dns_check_command.rb b/lib/invoker/ipc/dns_check_command.rb
index 48876e1..f1ff697 100644
--- a/lib/invoker/ipc/dns_check_command.rb
+++ b/lib/invoker/ipc/dns_check_command.rb
@@ -2,12 +2,9 @@ module Invoker
   module IPC
     class DnsCheckCommand < BaseCommand
       def run_command(message_object)
-        process_detail = Invoker.dns_cache[message_object.process_name]
+        process_detail = Invoker.dns_cache.find_process(message_object.host, message_object.path)
 
-        dns_check_response = Invoker::IPC::Message::DnsCheckResponse.new(
-          process_name: message_object.process_name,
-          port: process_detail ? process_detail['port'] : nil
-        )
+        dns_check_response = Invoker::IPC::Message::DnsCheckResponse.new(process_detail || {})
         send_data(dns_check_response)
         true
       end
diff --git a/lib/invoker/ipc/message.rb b/lib/invoker/ipc/message.rb
index f4a22f2..2d7d6b0 100644
--- a/lib/invoker/ipc/message.rb
+++ b/lib/invoker/ipc/message.rb
@@ -146,7 +146,7 @@ class Remove < Base
 
       class DnsCheck < Base
         include Serialization
-        message_attributes :process_name
+        message_attributes :host, :path
       end
 
       class DnsCheckResponse < Base
diff --git a/lib/invoker/power/balancer.rb b/lib/invoker/power/balancer.rb
index 91f76d1..77cdc5b 100644
--- a/lib/invoker/power/balancer.rb
+++ b/lib/invoker/power/balancer.rb
@@ -22,8 +22,8 @@ def post_init
 
     class Balancer
       attr_accessor :connection, :http_parser, :session, :protocol
-      DEV_MATCH_REGEX = /([\w-]+)\.dev(\:\d+)?$/
-      XIP_IO_MATCH_REGEX = /([\w-]+)\.\d+\.\d+\.\d+\.\d+\.xip\.io(\:\d+)?$/
+      DEV_MATCH_REGEX = /([\w.-]+)\.dev(\:\d+)?$/
+      XIP_IO_MATCH_REGEX = /([\w.-]+)\.\d+\.\d+\.\d+\.\d+\.xip\.io(\:\d+)?$/
 
       def self.run(options = {})
         start_http_proxy(InvokerHttpProxy, 'http', options)
@@ -48,6 +48,7 @@ def initialize(connection, protocol)
       end
 
       def install_callbacks
+        http_parser.on_url { |url| url_received(url) }
         http_parser.on_headers_complete { |headers| headers_received(headers) }
         http_parser.on_message_complete { |full_message| complete_message_received(full_message) }
         connection.on_data { |data| upstream_data(data) }
@@ -60,12 +61,16 @@ def complete_message_received(full_message)
         http_parser.reset
       end
 
+      def url_received(url)
+        @path = url
+      end
+
       def headers_received(headers)
         if @session
           return
         end
         @session = UUID.generate()
-        dns_check_response = select_backend_config(headers['Host'])
+        dns_check_response = select_backend_config(headers['Host'], @path)
         if dns_check_response && dns_check_response.port
           connection.server(session, host: '0.0.0.0', port: dns_check_response.port)
         else
@@ -107,11 +112,11 @@ def extract_host_from_domain(host)
 
       private
 
-      def select_backend_config(host)
-        matching_string = extract_host_from_domain(host)
+      def select_backend_config(domain, path)
+        matching_string = extract_host_from_domain(domain)
         return nil unless matching_string
-        if selected_app = matching_string[1]
-          dns_check(process_name: selected_app)
+        if host = matching_string[1]
+          dns_check(host: host, path: path)
         else
           nil
         end
diff --git a/lib/invoker/power/http_parser.rb b/lib/invoker/power/http_parser.rb
index 430e47a..af1f0e5 100644
--- a/lib/invoker/power/http_parser.rb
+++ b/lib/invoker/power/http_parser.rb
@@ -8,6 +8,7 @@ def initialize(protocol)
         @parser = HTTP::Parser.new
         @header = {}
         initialize_message_content
+        parser.on_url { |url| url_received(url) }
         parser.on_headers_complete { complete_headers_received }
         parser.on_header_field { |field_name| @last_key = field_name }
         parser.on_header_value { |field_value| header_value_received(field_value) }
@@ -15,6 +16,10 @@ def initialize(protocol)
         parser.on_message_complete { complete_message_received }
       end
 
+      def on_url(&block)
+        @on_url_callback = block
+      end
+
       # define a callback for invoking when complete header is parsed
       def on_headers_complete(&block)
         @on_headers_complete_callback = block
@@ -63,6 +68,12 @@ def complete_headers_received
           @on_headers_complete_callback.call(@header)
         end
       end
+      
+      def url_received(url)
+        if @on_url_callback
+          @on_url_callback.call(url)
+        end
+      end
     end
   end
 end
diff --git a/spec/invoker/config_spec.rb b/spec/invoker/config_spec.rb
index d915741..941f12c 100644
--- a/spec/invoker/config_spec.rb
+++ b/spec/invoker/config_spec.rb
@@ -183,7 +183,7 @@
 
         expect(dns_cache.dns_data).to_not be_empty
         expect(dns_cache.dns_data['web']).to_not be_empty
-        expect(dns_cache.dns_data['web']['port']).to eql 9001
+        expect(dns_cache.dns_data['web'].first[2]).to eql 9001
       ensure
         File.delete("/tmp/Procfile")
       end
diff --git a/spec/invoker/ipc/dns_check_command_spec.rb b/spec/invoker/ipc/dns_check_command_spec.rb
index ca0955c..9f72c34 100644
--- a/spec/invoker/ipc/dns_check_command_spec.rb
+++ b/spec/invoker/ipc/dns_check_command_spec.rb
@@ -5,9 +5,9 @@
   let(:client) { Invoker::IPC::ClientHandler.new(client_socket) }
 
   describe "dns check for valid process" do
-    let(:message_object) { MM::DnsCheck.new(process_name: 'lolbro') }
+    let(:message_object) { MM::DnsCheck.new(host: 'lolbro', path: '/') }
     it "should response with dns check response" do
-      invoker_dns_cache.expects(:[]).returns('port' => 9000)
+      invoker_dns_cache.expects(:find_process).returns('process_name' => 'lolbro', 'port' => 9000)
       client_socket.string = message_object.encoded_message
 
       client.read_and_execute
@@ -18,9 +18,9 @@
   end
 
   describe "dns check for invalid process" do
-    let(:message_object) { MM::DnsCheck.new(process_name: 'foo') }
+    let(:message_object) { MM::DnsCheck.new(host: 'foo', path: '/') }
     it "should response with dns check response" do
-      invoker_dns_cache.expects(:[]).returns('port' => nil)
+      invoker_dns_cache.expects(:find_process).returns(nil)
       client_socket.string = message_object.encoded_message
 
       client.read_and_execute
diff --git a/spec/invoker/power/balancer_spec.rb b/spec/invoker/power/balancer_spec.rb
index b4a41b8..aa80ef0 100644
--- a/spec/invoker/power/balancer_spec.rb
+++ b/spec/invoker/power/balancer_spec.rb
@@ -27,7 +27,7 @@
       expect(match).to_not be_nil
 
       matching_string = match[1]
-      expect(matching_string).to eq("bar")
+      expect(matching_string).to eq("emacs.bar")
     end
 
     it "should match hello-world.dev" do
@@ -61,7 +61,7 @@
       expect(match).to_not be_nil
 
       matching_string = match[1]
-      expect(matching_string).to eq("bar")
+      expect(matching_string).to eq("emacs.bar")
     end
 
     it "should match hello-world.10.0.0.1.xip.io" do
diff --git a/spec/invoker/power/http_parser_spec.rb b/spec/invoker/power/http_parser_spec.rb
index 7157256..17d4df8 100644
--- a/spec/invoker/power/http_parser_spec.rb
+++ b/spec/invoker/power/http_parser_spec.rb
@@ -5,6 +5,16 @@
 
   describe "complete message received" do
     before { parser.reset }
+    it "should call url received with url" do
+      @header, @path = nil
+      parser.on_headers_complete { |header| @header = header }
+      parser.on_url { |url| @path = url }
+      parser << "GET /blah HTTP/1.1\r\n"
+      parser << "Host: localhost\r\n"
+
+      expect(@path).to eql "/blah"
+    end
+
     it "should call header received with full header" do
       @header = nil
       parser.on_headers_complete { |header| @header = header }

From 507288089e810779d23e4e13d895d1899b531ecf Mon Sep 17 00:00:00 2001
From: David Lee <davidomundo@gmail.com>
Date: Mon, 2 Mar 2015 00:37:43 -0800
Subject: [PATCH 2/4] Add support for 'location'

k
---
 lib/invoker/dns_cache.rb      | 46 +++++++++++++++++++++++------------
 lib/invoker/ipc/message.rb    |  2 +-
 lib/invoker/parsers/config.rb |  1 +
 spec/invoker/config_spec.rb   |  2 +-
 4 files changed, 33 insertions(+), 18 deletions(-)

diff --git a/lib/invoker/dns_cache.rb b/lib/invoker/dns_cache.rb
index e213dc7..d8406c5 100644
--- a/lib/invoker/dns_cache.rb
+++ b/lib/invoker/dns_cache.rb
@@ -3,27 +3,36 @@ class DNSCache
     attr_accessor :dns_data
 
     # INI:
-    # [www.app]
+    # [app]
     # port = 8000
+    # location = www2.app/blah
     #
-    # [www.app/chat]
+    # [chat]
     # port = 8001
+    # location www.app/chat
     #
-    # [app]
+    # [api]
     # port = 8002
-    #
-    # [app/api]
-    # port = 8003
+    # location = www.app/api
     #
     # dns_data:
     # {
-    #   'www.app' => [
-    #     ['/', 8000],
-    #     ['/chat', 8001]
+    #   'api' => [
+    #     ['', 8002]
     #   ],
     #   'app' => [
-    #     ['/', 8002],
-    #     ['/api, 8003]
+    #     ['', 8000]
+    #   ],
+    #   'chat' => [
+    #     ['', 8001]
+    #   ],
+    #   'www.app' => [
+    #     ['', 8000],
+    #     ['/api, 8002],
+    #     ['/chat, 8001]
+    #   ],
+    #   'www2.app' => [
+    #     ['/blah', 8000]
     #   ]
     # }
     def initialize(config)
@@ -32,6 +41,11 @@ def initialize(config)
       Invoker.config.processes.each do |process|
         if process.port
           add(process.label, process.port)
+          if process.location
+            process.location.split(' ').each do |loc|
+              add(loc, process.port)
+            end
+          end
         end
       end
     end
@@ -42,9 +56,9 @@ def find_process(host, path)
           host = host.split('.', 2)[1]
         end
 
-        dns_data[host].reverse_each {|prefix, label, port|
+        dns_data[host].reverse_each {|prefix, port|
           if path_matches_prefix?(path, prefix)
-            return {:process_name => label, :port => port}
+            return {:port => port}
           end
         }
 
@@ -52,10 +66,10 @@ def find_process(host, path)
       }
     end
 
-    def add(name, port)
+    def add(location, port)
       @dns_mutex.synchronize {
-        host, path_prefix = split_host_path(name)
-        (dns_data[host] << [path_prefix.to_s, name, port]).sort!
+        host, path_prefix = split_host_path(location)
+        (dns_data[host] << [path_prefix.to_s, port]).sort_by! &:length
       }
     end
 
diff --git a/lib/invoker/ipc/message.rb b/lib/invoker/ipc/message.rb
index 2d7d6b0..e48a8d8 100644
--- a/lib/invoker/ipc/message.rb
+++ b/lib/invoker/ipc/message.rb
@@ -151,7 +151,7 @@ class DnsCheck < Base
 
       class DnsCheckResponse < Base
         include Serialization
-        message_attributes :process_name, :port
+        message_attributes :port
       end
 
       class Ping < Base
diff --git a/lib/invoker/parsers/config.rb b/lib/invoker/parsers/config.rb
index f8dc67b..a65f70c 100644
--- a/lib/invoker/parsers/config.rb
+++ b/lib/invoker/parsers/config.rb
@@ -94,6 +94,7 @@ def make_pconfig(section)
           cmd: section["command"]
         }
         pconfig['port'] = section['port'] if section['port']
+        pconfig['location'] = section['location'] if section['location']
         pconfig['disable_autorun'] = section['disable_autorun'] if section['disable_autorun']
 
         OpenStruct.new(pconfig)
diff --git a/spec/invoker/config_spec.rb b/spec/invoker/config_spec.rb
index 941f12c..ae227d7 100644
--- a/spec/invoker/config_spec.rb
+++ b/spec/invoker/config_spec.rb
@@ -183,7 +183,7 @@
 
         expect(dns_cache.dns_data).to_not be_empty
         expect(dns_cache.dns_data['web']).to_not be_empty
-        expect(dns_cache.dns_data['web'].first[2]).to eql 9001
+        expect(dns_cache.dns_data['web'].first[1]).to eql 9001
       ensure
         File.delete("/tmp/Procfile")
       end

From 7f9e9fc4c0609b37057d1c7c098dc08880da5b94 Mon Sep 17 00:00:00 2001
From: David Lee <davidomundo@gmail.com>
Date: Mon, 2 Mar 2015 05:04:00 -0800
Subject: [PATCH 3/4] Handle paths with queries more robustly

---
 lib/invoker/dns_cache.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/invoker/dns_cache.rb b/lib/invoker/dns_cache.rb
index d8406c5..685e36e 100644
--- a/lib/invoker/dns_cache.rb
+++ b/lib/invoker/dns_cache.rb
@@ -79,7 +79,7 @@ def split_host_path(label)
     end
 
     def path_matches_prefix?(path, prefix)
-      path == prefix || path.start_with?(prefix + '/')
+      path.start_with?(prefix) && [nil, "/", "?"].member?(path[prefix.length])
     end
   end
 end

From d84a348678e6f9dc76871fd32750d3dc0837c34e Mon Sep 17 00:00:00 2001
From: David Lee <davidomundo@gmail.com>
Date: Mon, 2 Mar 2015 05:04:57 -0800
Subject: [PATCH 4/4] Disconnect from backend after each response

This is to avoid issues where subsequent requests from a persistent HTTP
connection would be directed to a stale proxy regardless of the
location.

Only a problem now because we're taking paths into consideration for
proxy routing, whereas before, backends could be reused since persistent
HTTP connections were guaranteed to end up with the same backend anyway.
---
 lib/invoker/power/balancer.rb | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/lib/invoker/power/balancer.rb b/lib/invoker/power/balancer.rb
index 77cdc5b..71088b3 100644
--- a/lib/invoker/power/balancer.rb
+++ b/lib/invoker/power/balancer.rb
@@ -43,6 +43,7 @@ def initialize(connection, protocol)
         @connection = connection
         @protocol = protocol
         @http_parser = HttpParser.new(protocol)
+        @response_http_parser = HttpParser.new(protocol)
         @session = nil
         @buffer = []
       end
@@ -51,11 +52,26 @@ def install_callbacks
         http_parser.on_url { |url| url_received(url) }
         http_parser.on_headers_complete { |headers| headers_received(headers) }
         http_parser.on_message_complete { |full_message| complete_message_received(full_message) }
+
+        @response_http_parser.on_message_complete { response_complete }
+
         connection.on_data { |data| upstream_data(data) }
         connection.on_response { |backend, data| backend_data(backend, data) }
         connection.on_finish { |backend, name| frontend_disconnect(backend, name) }
       end
 
+      def response_complete
+        # disconnect from backend after each response, since subsequent
+        # requests from persistent HTTP connections might be proxied to a stale
+        # backend
+        EventMachine.next_tick do # still needs chance to send data
+          connection.unbind_backend(@session)
+          @session = nil
+          @response_http_parser.reset
+          http_parser.reset
+        end
+      end
+
       def complete_message_received(full_message)
         connection.relay_to_servers(full_message)
         http_parser.reset
@@ -66,9 +82,6 @@ def url_received(url)
       end
 
       def headers_received(headers)
-        if @session
-          return
-        end
         @session = UUID.generate()
         dns_check_response = select_backend_config(headers['Host'], @path)
         if dns_check_response && dns_check_response.port
@@ -93,6 +106,7 @@ def append_for_http_parsing(data)
       end
 
       def backend_data(backend, data)
+        @response_http_parser << data
         @backend_data = true
         data
       end