Dignus.Commands 1.0.6

Dignus.Commands

Lightweight command execution system for local console and telnet remote control.

간단한 로컬 콘솔 명령 실행과 텔넷 기반 원격 명령 실행을 지원하는 커맨드 시스템입니다.

Features / 특징

English

• Attribute based command registration
• Delegate based command registration
• Async command execution
• CancellationToken based cancellation
• Middleware pipeline support
• Local console command runner
• Telnet remote command runner

Korean

• Attribute 기반 커맨드 등록
• Delegate 기반 커맨드 등록
• 비동기 커맨드 실행
• CancellationToken 기반 취소 지원
• 미들웨어 파이프라인 지원
• 로컬 콘솔 실행 지원
• 텔넷 기반 원격 명령 실행

Quick Start

using Dignus.Commands;

var module = new LocalCommandRunner();

module.AddCommand<Close>();

module.Build();
module.Run();

Local Command Runner

Run commands directly from the local console.

로컬 콘솔에서 직접 명령을 입력받아 실행합니다.

using Dignus.Commands;

var module = new LocalCommandRunner();

module.AddCommand<Close>();

module.Build();
module.Run();

Telnet Command Runner

Start a telnet server and execute commands remotely.

텔넷 서버를 열고 외부 텔넷 클라이언트에서 접속하여 명령을 실행합니다.

using Dignus.Commands;

var module = new TelnetCommandRunner(port: 50000);

module.AddCommand<Close>();

module.Build();
module.Run();

Connect via telnet:

telnet 127.0.0.1 50000

Note

There is no dedicated telnet client module.
You connect using any telnet client.

Command Class

Create a command by implementing ICommand.

using Dignus.Commands.Attributes;
using Dignus.Commands.Interfaces;
using Dignus.Actor.Core;
using System.Diagnostics;

[Command("close")]
internal class Close : ICommand
{
    public Task InvokeAsync(string[] args, IActorRef sender, CancellationToken cancellationToken)
    {
        Process.GetCurrentProcess().Close();
        return Task.CompletedTask;
    }

    public string Print()
    {
        return "close process";
    }
}

Register the command

module.AddCommand<Close>();

Delegate Command

Commands can also be registered using delegates.

module.AddCommand("loop", "loop example", TestAsync);

async Task TestAsync(string[] args, IActorRef sender, CancellationToken cancellationToken)
{
    var count = 0;

    while (cancellationToken.IsCancellationRequested == false)
    {
        sender.Post(new CommandResponseMessage()
        {
            Content = $"sleep : {count++}"
        });

        await Task.Delay(2000, cancellationToken);
    }

    sender.Post(new CommandResponseMessage()
    {
        Content = $"end sleep : {count++}"
    });
}

Middleware

You can add middleware to the command execution pipeline.

module.AddMiddleware((ref CommandPipelineContext context, ref AsyncPipelineNext<CommandPipelineContext> next) =>
{
    var auth = context.Command.GetType().GetCustomAttribute<AuthAttribute>();

    if (auth.Execute(context) == false)
    {
        context.SenderActorRef.Post(new CommandResponseMessage()
        {
            Content = "invalid auth"
        });

        return Task.CompletedTask;
    }

    return next.InvokeAsync(ref context);
});

Command Execution Flow

User Input
     │
     ▼
Command Parser
     │
     ▼
Middleware Pipeline
     │
     ▼
Command Execution
     │
     ▼
CommandResponseMessage

Cancellation

Long running commands should support cancellation.

while (cancellationToken.IsCancellationRequested == false)
{
    await Task.Delay(1000, cancellationToken);
}

If a telnet connection closes, a CancelCommandMessage will be sent.

Output Message

Send output using CommandResponseMessage.

sender.Post(new CommandResponseMessage()
{
    Content = "hello"
});

Default Commands

Module Lifecycle

var module = new LocalCommandRunner();

module.AddCommand<Close>();

module.Build();
module.Run();

Execution order

1. Create module
2. Register commands
3. Register middleware
4. Build()
5. Run()

Run() must be called after Build().