Practical Modular Monolith, built with .Net 8, DDD, CQRS, Vertical Slice Architecture, Event-Driven Architecture, and the latest technologies.
MIT License
π A practical and imaginary Modular Monolith for implementing an infrastructure for up and running Modular system with the latest technology and architecture like Vertical Slice Architecture, Event Driven Architecture, CQRS, DDD, gRpc and Cap in .Net 8.
π‘ This project is not business-oriented and most of my focus was in the thechnical part for implement a Modular system with a sample project. In this project I implemented some concept in Modular Monolith like Inmemory Broker, Tracing, Event Driven Architecture, Vertical Slice Architecture, CQRS, DDD and gRpc.
Vertical Slice Architecture
for architecture level.Domain Driven Design (DDD)
to implement all business processes in modules.InMememoryBroker
on top of Cap
for Event Driven Architecture
between our modules.Inbox Pattern
on top of Cap
for ensuring message idempotency for receiver and Exactly once Delivery
.Outbox Pattern
on top of Cap
for ensuring no message is lost and there is at Least One Delivery
.CQRS
implementation with MediatR
library.Postgres
for database level in our modules.Unit Testing
, Integration Testing
for testing level.Fluent Validation
and a Validation Pipeline Behaviour
on top of MediatR
.Docker-Compose
and Kubernetes
for our deployment mechanism.OpenTelemetry
for distributed tracing.IdentityServer
for implementation authentication and authorization base on OpenID-Connect
and OAuth2
.πThis project is a work in progress, new features will be added over time.π
I will try to register future goals and additions in the Issues section of this repository.
High-level plan is represented in the table
Feature | Status |
---|---|
API | Completed βοΈ |
Identity Module | Completed βοΈ |
Flight Module | Completed βοΈ |
Passenger Module | Completed βοΈ |
Booking Module | Completed βοΈ |
Building Blocks | Completed βοΈ |
.NET 6
- .NET Framework and .NET Core, including ASP.NET and ASP.NET CoreMVC Versioning API
- Set of libraries which add service API versioning to ASP.NET Web API, OData with ASP.NET Web API, and ASP.NET CoreEF Core
- Modern object-database mapper for .NET. It supports LINQ queries, change tracking, updates, and schema migrationsCap
- An EventBus with local persistent message functionality for system integration in SOA or Microservice architecture.MediatR
- Simple, unambitious mediator implementation in .NET.FluentValidation
- Popular .NET validation library for building strongly-typed validation rulesSwagger & Swagger UI
- Swagger tools for documenting API's built on ASP.NET CoreSerilog
- Simple .NET logging with fully-structured eventsPolly
- Polly is a .NET resilience and transient-fault-handling library that allows developers to express policies such as Retry, Circuit Breaker, Timeout, Bulkhead Isolation, and Fallback in a fluent and thread-safe mannerScrutor
- Assembly scanning and decoration extensions for Microsoft.Extensions.DependencyInjectionOpentelemetry-dotnet
- The OpenTelemetry .NET ClientDuendeSoftware IdentityServer
- The most flexible and standards-compliant OpenID Connect and OAuth 2.x framework for ASP.NET CoreEasyCaching
- Open source caching library that contains basic usages and some advanced usages of caching which can help us to handle caching more easier.Mapster
- Convention-based object-object mapper in .NET.Hellang.Middleware.ProblemDetails
- A middleware for handling exception in .Net CoreIdGen
- Twitter Snowflake-alike ID generator for .NetMagicOnion
- gRPC based HTTP/2 RPC Streaming Framework for .NET, .NET Core and Unity.Identity Module
: The Identity Service is a bounded context for the authentication and authorization of users using Identity Server. This service is responsible for creating new users and their corresponding roles and permissions using .Net Core Identity and Jwt authentication and authorization.
Flight Module
: The Flight Service is a bounded context CRUD
service to handle flight related operations.
Passenger Module
: The Passenger Service is a bounded context for managing passenger information, tracking activities and subscribing to get notification for out of stock products.
Booking Module
: The Booking Service is a bounded context for managing all operation related to booking ticket.
Api
: The Api Project use for hosting all modules in one place.
Note: We don't have separated API project for each module because they are not microervice and shouldn't host separately, so for hosting all modules, we just use one Api project.
In this project I used a mix of clean architecture, vertical slice architecture and I used feature folder structure to structure my files.
We have a separate module (IdentityServer) for authentication and authorization of each request. Once signed-in users are issued a JWT token. This token is used by other module to validate the user, read claims and allow access to authorized/role specific endpoints.
I used MagicOnion for sync
communication between our modules. This framework is based on gRPC
, which is a fast and compact binary network transport for HTTP/2. However, unlike plain gRPC, it treats C# interfaces as a protocol schema, enabling seamless code sharing between C# projects without .proto (Protocol Buffers IDL).
I used In-Memory Queue as my MessageBroker for async
communication between modules using the eventual consistency mechanism. Each modules uses Cap to interface with In-Memory Queue for easy use messaging, availability, reliability, etc.
modules are event based
which means they can publish and/or subscribe to any events occurring in the setup. By using this approach for communicating between modules, each module does not need to know about the other module or handle errors occurred in other modules.
I treat each request as a distinct use case or slice, encapsulating and grouping all concerns from front-end to back.
When adding or changing a feature in an application in n-tire architecture, we are typically touching many "layers" in an application. We are changing the user interface, adding fields to models, modifying validation, and so on. Instead of coupling across a layer, we couple vertically along a slice. We minimize coupling
between slices
, and maximize coupling
in a slice
.
With this approach, each of our vertical slices can decide for itself how to best fulfill the request. New features only add code, we're not changing shared code and worrying about side effects.
Instead of grouping related action methods in one controller, as found in traditional ASP.net controllers, I used the REPR pattern. Each action gets its own small endpoint, consisting of a route, the action, and an IMediator
instance (see MediatR). The request is passed to the IMediator
instance, routed through a Mediatr pipeline
where custom middleware can log, validate and intercept requests. The request is then handled by a request specific IRequestHandler
which performs business logic before returning the result.
The use of the mediator pattern in my controllers creates clean and thin controllers. By separating action logic into individual handlers we support the Single Responsibility Principle and Don't Repeat Yourself principles, this is because traditional controllers tend to become bloated with large action methods and several injected Services
only being used by a few methods.
I used CQRS to decompose my features into small parts that makes our application:
Using the CQRS pattern, we cut each business functionality into vertical slices, for each of these slices we group classes (see technical folders structure) specific to that feature together (command, handlers, infrastructure, repository, controllers, etc). In our CQRS pattern each command/query handler is a separate slice. This is where you can reduce coupling between layers. Each handler can be a separated code unit, even copy/pasted. Thanks to that, we can tune down the specific method to not follow general conventions (e.g. use custom SQL query or even different storage). In a traditional layered architecture, when we change the core generic mechanism in one layer, it can impact all methods.
For installing our requirement package with .NET cli tools, we need to install dotnet tool manifest
.
dotnet new tool-manifest
And after that we can restore our dotnet tools packages with .NET cli tools from .config
folder and dotnet-tools.json
file.
dotnet tool restore
Run the following commands for Config SSL in your system
dotnet dev-certs https -ep %USERPROFILE%\.aspnet\https\aspnetapp.pfx -p {password here}
dotnet dev-certs https --trust
Note: for running this command in
powershell
use$env:USERPROFILE
instead of%USERPROFILE%
We have a separate Docker file for setting up and running the infrastracture.yaml independently.
docker-compose -f ./deployments/docker-compose/infrastracture.yaml up -d
TODO π·ββοΈ Deployment App in Docker-Compose
Build
To build
all microservices, run this command in the root
of the project:
dotnet build
Run
To run
each microservice, run this command in the root of the Api
folder of each microservice where the csproj
file is located:
dotnet run
Test
To test
all microservices, run this command in the root
of the project:
dotnet test
Documentation Apis
Each microservice has a Swagger OpenAPI
. Browse to /swagger
for a list of endpoints.
As part of API testing, I created the booking.rest file which can be run with the REST Client VSCode plugin
.
If you like my work, feel free to:
Thanks a bunch for supporting me!
Thanks to all contributors, you're awesome and this wouldn't be possible without you! The goal is to build a categorized community-driven collection of very well-known resources.
Please follow this contribution guideline to submit a pull request or create the issue.
This project is made available under the MIT license. See LICENSE for details.