Overview of My Submission
This submission is to switch my application (Sanic Currency Exchange API) from using PostgresDB to be able to use Redis Stack(RedisJSON) as data store, as shown in the diagram, it contains 3 parts of work.
- Refactoring, to implement Dependency Injection to split Database logic and Application logic.
- Auto Test/Regression Test, to guarantee that before and after db switch the API behaves the same, this part of work was done in Postman, and the test scripts were shared in repo.
- Switch Data Store to RedisJson, to implement a Redis repository which keep the same behaviour as Postgres repository, to make the data store switch happen easily and smoothly.
The Idea
I cloned this Currency API (Github link below) about 3 years ago and kept maintaining it. The initial thoughts were maintaining the dependencies to avoid some security problems. Gradually, I started to re-write the application codes to make it more maintainable, readable. (This is a long way to go, I am sure it has not been finished yet, 😀)
This API is to fetch currency rates from Europe Central Bank, and offer the rates in RESTful API.
Since I saw the Redis hackathon announcement, I got this idea to switch data store from Postgres to Redis JSON. I used Redis before as a caching layer for application, but this is my first time to use the Redis modules. This implementation probably have a lot to improve, please feel free to leave comments to make it better and help me to learn more about Redis JSON and Redis Stack modules.
Submission Category: MEAN/MERN Mavericks
- Use Redis to the RESTful API to add caching and advanced searching capabilities using JSON module.
- Use Redis as a primary database instead of Postgres.
- Redis Stack docker image was used here instead of Redis Cloud, to keep the Postgres and Redis Stack have the same hardware spec.
How the data is stored:
The data is store as a document, for each day of the currency rates.
{
"2020-01-01": {
"USD": 1,
"EUR": 1.1,
"AUD": 0.97
}
}
How the data is accessed:
In python codes, the data is accessed through a simple get
r.json().get('2020-01-01')
Language Used
- Python (Sanic Framework)
- Javascript
Link to Code
tim-hub
/
sanic-currency-exchange-rates-api
This is a self hosted, free, open source Python Currency Exchange Rate API fork.
Sanic Currency Exchange Rates Api
This is a self hosted, free, currency exchange rate api, free demo at exchange-rate.bai.uno.
The current and historical foreign exchange rates data are from European Central Bank .
- More about Redis Stack
Usage
Latest date will be returned, if the date was not in Euro Central Bank history records
Latest & specific date rates
Get the latest foreign exchange rates.
GET /api/latest
Get historical rates for any day since 1999.
GET /api/2018-03-26
Rates are quoted against the Euro by default. Quote against a different currency by setting the base parameter in your request.
GET /api/latest?base=USD
Request specific exchange rates by setting the symbols parameter.
GET /api/latest?symbols=USD,GBP
Rates history
Get historical rates for a time period.
GET /api/history?start_at=2018-01-01&end_at=2018-09-01
Limit results to specific exchange rates to save bandwidth with the symbols parameter.
GET /api/history?start_at=2018-01-01&end_at=2018-09-01&symbols=ILS,JPY
Quote the historical rates against a different currency.
GET /api/history?start_at=2018-01-01&end_at=2018-09-01&base=USD
Client side
…Additional Resources / Info
Collaborators
This is a solo submission.
- Check out Redis OM, client libraries for working with Redis as a multi-model database.
- Use RedisInsight to visualize your data in Redis.
- Sign up for a free Redis database.
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