ledger-exp

Table Structure

Application Architecture

• This project uses PostgreSQL as the database solution and Redis for caching and concurrency control (distlock).
• For observability, the open-source project OpenTelemetry was chosen, allowing for agnostic distribution of metrics and spans to different providers.

Packages

• The /cmd directory contains the application bootstrap/main.
• The /internal directory contains business logic packages:
  1. accounts: Manages poster accounts;
  2. api: Implements HTTP handlers;
  3. balances: Manages account balances, provided by the transactions_balances view;
  4. holders: Manages posters;
  5. statements: Displays account statements based on transactions, separated from the transactions package for better filter autonomy;
  6. transactions: Manages transactions like credits, debits, and transfers between accounts.
• The /migrations directory contains all SQL scripts (DDL) for database migration.
• The /pkg directory includes all packages used in the application that are not business-related.

How to Run the Project?

docker-compose --env-file .env-docker up -d

Once all services are up and running, they will be exposed at: Database migration will be executed along with docker-compose startup

• ledger-exp-api -> localhost:8080
• postgres -> localhost:5432
• redis-commander -> localhost:8081 root - root
• jaeger -> localhost:16686
• prometheus -> localhost:9090

How to Run Unit and Integration Tests?

Unit Tests:

go test -json -race -tags=unit ./...

Integration Tests:

go test -json -race -tags=integration ./...

How to Test the API?

You can use the Insomnia exported file, which contains all mapped endpoints with usage examples. File

For a consistent flow, follow these endpoints:

1. POST /v1/holders
2. POST /v1/accounts
3. Create transactions:
   1. POST /v1/transactions/credits -> Credit the account.
   2. POST /v1/transactions/debits -> Debit the account.
   3. POST /v1/transactions/p2p -> Transfer between accounts.
4. GET /v1/accounts/:accountID/statements -> Account statement.
5. GET /v1/accounts/:accountID/balances -> Check account balance.

Additional Information

1. How are mocks generated for tests?
   • In the ./scripts directory, there's a shell file that maps all files/interfaces to generate a mock.
2. How does database migration work?
   • Database migration is handled by the database-migration service defined in the docker-compose.yml.
3. How does observability work?
   • The OpenTelemetry Collector service defined in the docker-compose.yml receives all spans and metrics generated by the application and transmits them to Jaeger and Prometheus, respectively.