Geolocation service

Goals

• to provide an interface to access geolocation data.
• to provide a default csv importer that parses and imports csv data to a database.

Design

This library can be summarized using two interfaces:

Importer

// Importer provides API to parse and import geolocation data.
type Importer interface {
	Parse(file string) (map[string]*GeoData, error)
	Import(map[string]*GeoData) (Stats, error)
}

CSV importer implements this interface. This can easily be extended to other importers like, a json importer.

GeoDataProvider

// GeoDataProvider gives access to geolocation data.
type GeoDataProvider interface {
	Get(ip string) (*GeoData, error)
	SaveAll(data map[string]*GeoData) error
}

It allows to access or store geolocation data. store layer implements this interface using postgres but it can be easily be replaced with other user-defined implementation of store.

Trade offs

• I've used postgres for store layer but a key-value store would have been a better choice.
• Case when csv headers are in a different order is not handled.
• Table name is hardcoded, could be passed from the environment.

How to run the import script

1. Spin up a postgres container using make start-postgres-container

2. Set env DB_CONN_STR to the url of the database.

   export DB_CONN_STR="postgres://postgres:password@127.0.0.1:6432/postgres?sslmode=disable"

3. Set env CSV_FILE to the file name of csv.

   export CSV_FILE=filename

4. go run main.go

5. Stop the postgres container with make stop-postgres-container

Tests

To run tests for the entire repo

make test

Run e2e test to check the import functionality

make e2e-test

Run tests for store/db layer

make test-store