This repository follows the Standard Go Project Layout and contains a implementation of a simple url shortener.

IDs are generated using the "crypto/rand", the cryptographically secure random number generator from the go's stdlib. IDs are then encoded in base58 to be human-readable. Base58 has been used instead of base64 to avoid special chars like '/+=' that would have otherwise produced invalid URLs.

The length of IDs has been set to 7 chars in order to obtain low probability of collision in case of millions of short URLs. Indeed, with 7 chars we have 58^7 combinations, i.e. like 2,2×10¹².

To translate a short url to the corresponding long url within 10 ms I've used Redis with persistence as a key-value database. IDs are stored in Redis as key and long urls as value.

To store the metrics I've used a PostgreSQL database. Metrics are stored in a simple table where each row represents a request to the service.

The postgres database has been seeded with some dummy data. You can use the UrlID 'abcdefg' to obtain the results generated from the seeded data.

Whenever a user request for a short url translation, a goroutine is fired to update the metrics database.

I've prepared a list of simple scripts that can be used to test the running application. You can find them in the folder scripts.

• metrics.sh: invokes the metrics endpoint; it requires an id to be passed
• shorten.sh: invokes the shorten endpoint; it requires an url to be passed
• rount_trip.sh: invokes the shorten endpoint and then the process one; it requires an url to be passed

Please use the Docker Compose file in the deploy directory to execute the application.

docker-compose -f deploy/docker-compose.yml up

Then use the scripts in the scripts folder or curl to test the application

The default configuration is using the port 8080 on the host machine. If you need to use a different port on the host please change L:8 and L:14 of the deploy/docker-compose.yml file

• POST /shorten/anon: reads the data in the request body (in the format { "Url" : "https://sample.io/" }) and returns a short url
• GET /{id}: reads the id from the path and process the request redirecting to the long url associated to id
• GET /metrics/{id}: retrieves the metrics associated to the ID provided in the path