HAProxy Stream Processing Offload Agent Framework

Provides a Stream Processing Offload Protocol framework for ASP.NET Core or BedrockFramework.

It is fully asynchronuous and make heavy use of I/O Pipeline and Buffer to do high-performance I/O and protocol parsing.

Supports :

• SPOP version 2.0 specification
• All SPOP data types
• Capabilities :
  • Fragmentation in both ways. Meaning it can read fragmented frame from HAProxy and is ready to write them when HAProxy will support it
  • Pipelining
• SPOP Healthcheck

While it works fine and is production ready, some parts still need improvement. Contributions are welcome to improve :

• end-user experience and configuration
• add spop frame async capability (use an arbitrary connection to send agent ack frames)

Run examples

cd example
docker-compose up -d
curl -v http://localhost:8000

should show Ip_score response header

HTTP/1.1 GET /

Host: localhost:8000
Ip_score: 10
User-Agent: curl/7.68.0
Accept: */*

You can find agent source code in example/agent.

You may want to test bedrock flavor with docker compose -f docker-compose.yml -f docker-compose.bedrock.yml up.

Additionally, example folder contains a Dockerfile to build and run the HAProxy C example. You can run it with docker compose -f docker-compose.yml -f docker-compose.spoa-example.yml up and compare performance.

Usage

1. Add a SpoaApplication class to handle messages sent by HAProxy and return actions

   public class SpoaApplication : ISpoaApplication
   {
       public Task<IEnumerable<SpopAction>> ProcessMessagesAsync(long streamId, IEnumerable<SpopMessage> messages)
       {
           var responseActions = new List<SpopAction>();
   
           foreach (var myMessage in messages)
           {
               if (myMessage.Name == "my-message-name")
               {
                   int ip_score = 10;
   
                   if (IPAddress.IsLoopback((IPAddress)myMessage.Args["ip"])) ip_score = 20;
   
                   SpopAction setVar = new SetVarAction(VarScope.Request, "ip_score", ip_score);
                   responseActions.Add(setVar);
               }
           }
   
           return Task.FromResult((IEnumerable<SpopAction>)responseActions);
       }
   }

2. In Program.cs, Add Spoa Framework to a IWebHostBuilder.

   var builder = WebApplication.CreateEmptyBuilder(new WebApplicationOptions()
   {
       Args = args
   });
   
   builder.WebHost
       .UseKestrelCore()
       .ConfigureLogging(logging =>
       {
           logging.AddConsole();
       })
       .ConfigureServices(services =>
       {
           services.Configure<SpoaFrameworkOptions>(options =>
           {
               options.EndPoint = new IPEndPoint(IPAddress.Any, 12345);
           });
           services.AddSingleton<ISpoaApplication, SpoaApplication>();
           services.AddSpoaFramework();
       });
   
   var app = builder.Build();
   
   app.Run();

   Use your own Startup class if the Host is also serving Web content.

3. See example/haproxy to see how to configure haproxy. You will find extended information in the section 2 of the specification.