jangocheng/acerola

A Hexagonal Architecture solution with DDD, CQRS, TDD and SOLID using .NET Core 2.0 (Account Balance). All small features are testable and could be mocked. Adapters could be mocked or exchanged.

Architectural Style

A solution with Ports and Adapters.

Requirements

• Visual Studio 2017 with Update 3
• .NET SDK 2.0
• Docker

Main Architectural Concepts

Allow an application to equally be driven by users, programs, automated test or batch scripts, and to be developed and tested in isolation from its eventual run-time devices and databases.

As events arrive from the outside world at a port, a technology-specific adapter converts it into a usable procedure call and passes it to the application. The application is blissfully ignorant of the nature of the input device. When the application has something to send out, it sends it out through a port to an adapter, which creates the appropriate signals needed by the receiving technology (human or automated). The application has a semantically sound interaction with the adapters on all sides of it, without actually knowing the nature of the things on the other side of the adapters. Check out Alistair Cockburn blog post.

DDD

The use cases of this project is to manage an account balance with deposit and credits and its concepts is enforced by the Domain and Application. Also we use the Eric Evans terms like Entities, Value Object, Aggregates, Aggregate Root and etc. And everything is on a single Bounded Context.

CQRS

CQRS is an acronym for Command Query Responsibility Segregation. This pattern allow splitting our conceptual business model into two representations. The main representation resides on the Command Stack, to perform creates, updates and deletions. The display model resides inside the Query stack, where we can build a Query Model that make easier to aggregate information to display to clients and UI.

TDD

From the beginning of the project we developed Unit Tests and that helped us to enforce the business rules and to create an application that prevents bugs intead of finding them. We also have Use Case tests and Mapping Tests and a more sophistecated Integration Tests.

SOLID

The SOLID principles are all over the the solution. Knwoleadge of SOLID is not a prerequisite to understand and run the solution but it is highly recommended.

Microservice

Even though the definition of microservice may be different for different professionals. We have tried to value some aspects like Continous Delivery, modelled around Business Domain and Independent Deployment.

Logging

Loggin is a detail. We plugged Serilog and configured it to redirect every log message to files.

Docker

Docker is a detail of this architecture. And it was implemented to help us make a faster and reliable deployment. You could pull the Manga latest image any time.

Mongo DB

Mongo DB is a detail. At infrastructure layer we implemented the ICustomerWriteOnlyRepository to update the Mongo database.

.NET Core 2.0

.NET Core is a detail. Almost everything in this code base could be ported to older versions.

Environment setup

• Run the ./prerequisites.sh script to download the MongoDB image and run it as a Docker container. Please wait until the ~400mb download to be complete.

$ ./prerequisites.sh
Pulling mongodb (mongo:latest)...
latest: Pulling from library/mongo
Digest: sha256:2c55bcc870c269771aeade05fc3dd3657800540e0a48755876a1dc70db1e76d9
Status: Downloaded newer image for mongo:latest
Creating setup_mongodb_1 ...
Creating setup_mongodb_1
Creating setup_mongodb_1 ... done

• Check Mongo image with the the following commands:

$ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
mongo               latest              d22888af0ce0        17 hours ago        361MB
$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                            NAMES
ba28cf144478        mongo               "docker-entrypoint..."   2 days ago          Up 2 days           0.0.0.0:27017->27017/tcp                         setup_mongodb_1

If everything goes well MongoDB will be running with the following connection string mongodb://10.0.75.1:27017.

Running the latest Docker Build

If you like you can run the latest Docker image of this project as following:

$ docker run -p 8000:80 -d \
	-e modules__2__properties__ConnectionString=mongodb://10.0.75.1:27017 \
	--name acerola-backend \
	ivanpaulovich/acerola:latest

Then navigate to http://localhost:8000/swagger and play with de Web API.

We are live on Azure

You can play with the latest build by navigating to the Swagger client.

This source code and website should be used only for learning purposes and all data will be erased weekly.