/btc-service-poc

Primary LanguagePython

BTC Price Tracker (POC)

The approach utilizes yfinance, an embedded SQLite database managed with SQLAlchemy, and is powered by FastAPI to retrieve BTC prices in specified currencies at configurable time intervals. Daily and monthly averages are calculated based on the retrieved data, with configurable data retention.

API Endpoints

Protected API endpoints (accessible with the --api-key argument, passed as api-key header):

  1. /prices/current: Retrieves the current prices for specified currencies of a given ticker.
  2. /prices/averages: Provides the daily and monthly average prices for specified currencies.

Additional endpoints:

  1. /health: Checks the health status of the API.
  2. /docs: Accesses the OpenAPI schema, which is customized to include the API key in the security definitions.

Application structure

app
├── database | SQLAlchemy utilities and models
├── routers  | FastAPI routers (endpoints)
├── schemas  | Pydantic models for documentation
└── services | Background services (yfinance, etc.)

Running the application

The application follows The Twelve-Factor Methodology. Configuration can be provided at startup or through environmental variables (see also the .env file).

Example:

❯ pip install -r requirements.txt
❯ python3 app/main.py --help

usage: main.py [-h] [-d DIR] [-n NAME] [--retention-days RETENTION_DAYS] [-t TICKER] [-c CURRENCIES [CURRENCIES ...]]
               [--clean-up-interval-mins CLEAN_UP_INTERVAL_MINS] [--fetch-interval-mins FETCH_INTERVAL_MINS] [--api-key API_KEY] [--debug]
               [--host HOST] [--port PORT]

optional arguments:
  -h, --help            show this help message and exit
  --api-key API_KEY     API key for accessing the service
  --debug               Should we run the script in debug mode?
  --host HOST           Bind socket to this host
  --port PORT           Bind socket to this port

Database arguments:
  -d DIR, --dir DIR     Directory for SqLite database
  -n NAME, --name NAME  Name for SqLite database file
  --retention-days RETENTION_DAYS
                        Database data retention days

Currency parameters:
  -t TICKER, --ticker TICKER
                        Ticker symbol for the cryptocurrency
  -c CURRENCIES [CURRENCIES ...], --currencies CURRENCIES [CURRENCIES ...]
                        List of currencies to store prices for

Service(s) parameters:
  --clean-up-interval-mins CLEAN_UP_INTERVAL_MINS
                        Interval (in minutes) to run DB clean up
  --fetch-interval-mins FETCH_INTERVAL_MINS
                        Interval (in minutes) to retrieve prices

Docker testing


❯ docker build -t price-svc .
❯ docker run -p 8000:8000 --env-file .env price-svc
❯ curl -s -H "api-key: test" -X GET http://localhost:8000/prices/current | jq
{
  "prices": {
    "EUR": {
      "price": 72442.14224577416,
      "currency": "EUR",
      "request_time": "2024-05-23T18:32:22.299216",
      "server_data_time": "2024-05-23T18:32:17"
    },
    "CZK": {
      "price": 2928.2629724391445,
      "currency": "CZK",
      "request_time": "2024-05-23T18:32:22.299216",
      "server_data_time": "2024-05-23T18:32:17"
    }
  }
}

Minikube testing


❯ minikube start
❯ eval $(minikube docker-env)
❯ docker build -t price-svc .

❯ cd deployment/app-chart
❯ helm template . --name-template dummy --values ../values-test.yaml | kubectl apply -f -
❯ kubectl port-forward -n prices-svc service/dummy-app-chart 8000:8000
❯ curl -s -H "api-key: test" -X GET http://localhost:8000/prices/averages | jq
{
  "averages": {
    "EUR": {
      "daily_average": 72474.41419486888,
      "monthly_average": null
    },
    "CZK": {
      "daily_average": 2931.2929522524937,
      "monthly_average": null
    }
  }
}