This project demonstrates the Akka HTTP library and Scala to write a simple REST (micro)service. The project shows the following tasks that are typical for most Akka HTTP-based projects:
- starting standalone HTTP server,
- handling file-based configuration,
- logging,
- routing,
- deconstructing requests,
- unmarshalling JSON entities to Scala's case classes,
- marshaling Scala's case classes to JSON responses,
- error handling,
- issuing requests to external services,
- testing with mocking of external services.
The service in the template provides two REST endpoints - one which gives GeoIP info for given IP and another for calculating geographical distance between given pair of IPs. The project uses the service Telize which offers JSON IP and GeoIP REST API for free.
Start services with sbt:
$ sbt
> ~re-start
With the service up, you can start sending HTTP requests:
$ curl http://localhost:9000/ip/8.8.8.8
{
"city": "Mountain View",
"ip": "8.8.8.8",
"latitude": 37.386,
"country": "United States",
"longitude": -122.0838
}
$ curl -X POST -H 'Content-Type: application/json' http://localhost:9000/ip -d '{"ip1": "8.8.8.8", "ip2": "8.8.4.4"}'
{
"distance": 2201.448386715217,
"ip1Info": {
"city": "Mountain View",
"ip": "8.8.8.8",
"latitude": 37.386,
"country": "United States",
"longitude": -122.0838
},
"ip2Info": {
"ip": "8.8.4.4",
"country": "United States",
"latitude": 38.0,
"longitude": -97.0
}
}
Execute tests using test command:
$ sbt
> test