Card Management Service

L02

• Create and set up a template project
• Set up the configuration from file and environment variables
• Middleware for logging requests
• Middleware for adding and getting cards for user
• Store data in memory
• Card model:
  • Id
  • CVC
  • Pan (card number)
  • Expire (expiration date)
    • Month
    • Year
  • Name (card name, user-defined)
  • IsDefault (whether the card is default payment card)
  • UserId

Use multiple environments in ASP.NET Core

$Env:ASPNETCORE_ENVIRONMENT = "Development"
dotnet run --launch-profile "Development"

$Env:ASPNETCORE_ENVIRONMENT = "Staging"
dotnet run --launch-profile "Staging"

dotnet run --no-launch-profile

L03

• Added controllers for:
  • adding a card
  • deleting a card
  • getting a card or cards
  • changing card's name
• Configured swagger
• Added filters for logging requests and responses which hides card's secret data:
  • only 4 last digits of the pan is shown
  • CVC is hidden completely
• Added validation in one base model:
  • Luhn algorithm
  • card expiration date
  • during adding (including exceptions)

L04, L05

• Added
  • Entity Framework (EF) Core
  • PostgreSQL DB
  • Repository pattern for interaction with DB
• Removed
  • In-memory data

L06

• Added controller for Operations
  • Get (CardId param is optional)
    • /operation?cardId

    {
        "cardId": "d29f2fb4-409c-40b0-ad1e-4baa1758ea8e",
        "name": "operation02",
        "amount": 2
    }

  • Add operation with default card (Default card should exist)
    • /operation

    {
        "name": "operation02",
        "amount": 2
    }

  • Add operation with cardId. CardId should exist
    • Post /operation

    {
        "cardId": "d29f2fb4-409c-40b0-ad1e-4baa1758ea8e",
        "name": "operation02",
        "amount": 2
    }

  • Add operation with new card
    • Post /operation

    {
        "name": "operation01",
        "amount": 1,
        "card": {
            "pan": "4929722798964846",
            "expire": {
                "Month": 1,
                "Year": 2022
            },
            "cvc": "132"
        }
    }

• The application was created taking into account 12 factors

L07

• Added
  • Docker
  • Docker Compose

L08

• Created a new service of operations
• Operations API has been moved to a new service
• When carrying out an operation using new details, an asynchronous message is sent about the creation of a new card (the card Id is generated in the operation service).
  • RabbitMQ message broker
  • EasyNetQ library
• When carrying out an operation by card Id, the default card is requested synchronously
• The default card for transactions is requested synchronously

L09-10

• For HTTP communication between map services and operations, a policy has been configured using the Polly library for:
  • Retry
  • Circuit Breaker

Diagrams

Architecture

DB

Data

Rights Db (User)

Name	Password	AccessToken
Admin	1234	qwerty

Balancer DB (Route)

Number	ObjectName	ResourceConnection
1	card	{card-service}/card
2	operation	{operation-service}/operation

#	{card-service}	{operation-service}
debug	https://localhost:44333	https://localhost:44395
IIS	http://localhost/cardDataService	http://localhost/operationDataService
docker	http://card-service	http://operation-service

Card Db (Card)

Id	Cvc	Pan	Name	IsDefault	UserId	ExpirationDate
d29f2fb4-409c-40b0-ad1e-4baa1758ea8e	001	4360251111335365	card01	✔️	65ebe5d1-a883-46e2-805a-4c2d44eab438	12/2099
57d92bd8-413e-4377-8de2-f69d57ece143	002	4024007173305771	card02	❌	65ebe5d1-a883-46e2-805a-4c2d44eab438	06/2026
e0c6d6a1-5386-4690-9d63-23964e4be74f	003	2720473437781424	card03	✔️	3fa85f64-5717-4562-b3fc-2c963f66afa	05/2025

Operation Db (Operation)

Id	CardId	Name	Amount
48310dbe-a8b8-47b0-a21f-3180f656ce35	d29f2fb4-409c-40b0-ad1e-4baa1758ea8e	Petrol	1200
29d9170f-f06b-4c6f-ae9a-7f427517f171	57d92bd8-413e-4377-8de2-f69d57ece143	Products	2500
86fe5988-d76f-45ae-aefa-fe2dfd7e0e49	e0c6d6a1-5386-4690-9d63-23964e4be74f	Phone	37000