Lonely Mountain 　　　　　　　　　　　　　　　　[todo]

Lonely Mountain is a consumer wrapper library and consumer template, the consumer project is composing by one Worker to one or many Consumers. The Worker is root folder project and wrapper all Consumers with one appsettings, this appsettings is shared with others Consumers. The Consumer is a queue process project composing of three components Message, Validator, and Consumer.

Project structure

ROOT \
┣ LonelyMountain.Src \
┃ ┣ 📂 Connection \
┃ ┣ 📂 Consumer \
┃ ┣ 📂 Ioc \
┃ ┣ 📂 Queue \
┃ ┣ 📂 Subscriber \
┃ ┣ ┣  Bootstrap.cs 
┃ ┣ ┣  Worker.cs 
┃ ┗ ┗  LonelyMountain.Src.csproj
┃
┣ LonelyMountain.Template \
┃ ┣ 📂 templates \
┃ ┣ 📂 Consumer \
┃ ┣ ┣ 📂 .template.config \
┃ ┣ ┣ ┣  ┗ LonelyMountain.Src.csproj
┃ ┣ ┣ ┣  projectNameConsumer.cs 
┃ ┣ ┣ ┣  projectNameMessage.cs 
┃ ┣ ┣ ┣  projectNameValidator.cs 
┃ ┣ ┣ ┗  program.cs
┃ ┗  LonelyMountain.Template.csproj
┃
┣ LonelyMountain.Example \
┃ ┣ 📂 Worker \
┃ ┣ ┣ 📂 Customer \
┃ ┣ ┣ ┣  LonelyMountain.Example.csproj
┃ ┣ ┣ ┣  CustomerConsumer.cs 
┃ ┣ ┣ ┣  CustomerMessage.cs 
┃ ┣ ┣ ┣  CustomerValidator.cs 
┃ ┗ ┗ ┗  program.cs
┃
┣  docker-compose.yml
┣  README.md
┗  LonelyMountain.sln

Consumer Steps

When a consumer is triggered the following steps start

Message parse, Message validation, Message Processing, and Message queue management

, if any step failure the other steps not is called.

The message parses is the step when a queued message is parsed to an entity, the message only accepts JSON formats and must have the same structure as entity.

The message validation

The message validation step will validate the parsed entity using Fluent Validation. This step ensures the structure is exactly what the consumer needs.

The message processing

The message processing is the step when the message is processed, persisted, or else.

Message queue management

The message queue management is when the message is discarded when successful or sent to dead letter if any previous step fails.

Consumer components

The worker consumer is composed of Message, Validator, and Consumer.

Message

The message is the queued entity.

    public record CustomerMessage(string Name, string Identity, int Age);

Validator

The validator is the message validator using Fluent Validation

    public class CustomerValidator : AbstractValidator<CustomerMessage>
    {
        public CustomerValidator()
        {
            RuleFor(customer => customer.Name)
            .NotEmpty()
            .WithMessage("The [Name] can't be null or empty");

            RuleFor(customer => customer.Age)
            .NotEmpty()
            .WithMessage("The [Age] can't be null")
            .LessThan(18)
            .WithMessage("The customer can't not be younger than 18 years.");

        }
    }

Consumer

The consumer is the component when the message is processed using a Monad to enchain other components. The Queue annotation is used to categorize in Active queue (ActiveQueue), Dead letter queue (DlqQueue) and Topic (Topic).

    [ActiveQueue("insert-customer")]
    public class CustomerConsumer : AbstractConsumer<CustomerMessage>
    {
        public CustomerConsumer(IValidator<CustomerMessage> validator) : base(validator) { }
        protected override async Task<Result> Action(CustomerMessage message,IAcknowledgeManager acknowledge){
            await acknowledge.BasicAck();
            return await  Task.FromResult(Result.Success());
        }
    }

The consumer use CSharpFunctionalExtensions to wrap the result on a monad. The consumer result can be Success or Failure, the Failure must contain the failure reason. Failure

    protected override Task<Result> Action(Message message,IAcknowledgeManager acknowledge) =>
        return Task.FromResult(Result.Failure("Some error happened when I try process the message"));

How to use template

The template is not on nuget yet.

Install lm-consumer template

dotnet new --install LonelyMountain.Consumer

After install template create template using sourcing name

dotnet new lm-consumer -o YourProject.Worker.Customer

Generated folder

YourProject \
┣ 📂 Worker \
┣ ┣ 📂 Customer \
┣ ┣ ┣  YourProject.Worker.Customer.csproj
┣ ┣ ┣  CustomerConsumer.cs 
┣ ┣ ┣  CustomerMessage.cs 
┣ ┣ ┣  CustomerValidator.cs 
┣ ┣ ┗  program.cs
┣ ┣ YourProject.Worker.csproj
┗ ┗ appsettings.json

How to run

dotnet run -p YourProject.Worker.Customer
info: YourProject.Src.Worker[0]
      Worker start running at: 08/09/2021 01:09:53 -03:00
info: YourProject.Src.Subscriber.RabbitMQSubscriber[0]
      Start subscribing YourProject.Src.Queue.ActiveQueue consumer
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: Production

info: YourProject.Src.Subscriber.RabbitMQSubscriber[0]
      The insert-customer consumer was triggered
fail: YourProject.Src.Subscriber.RabbitMQSubscriber[0]
      An error was occurred when try processing insert-customer. Error: Error when try deserialize message body 'test' is an invalid JSON literal. Expected the literal 'true'. Path: $ | LineNumber: 0 | BytePositionInLine: 1.
info: YourProject.Src.Subscriber.RabbitMQSubscriber[0]
      The insert-customer was processed with success