url-shortener

Description

This is a simple url shortener web service written in Go.

It provides an API to shorten URLs and also to look up the original URLs based on the given identifier. Invalid requests will return HTTP 400, requests unknown identifiers will return HTTP 404. If there is a body returned it will contain a JSON document.

See API for a more detailed description.

Requests to shorten URLs that are already in the database will receive a new identifier regardless. This will allow us to separate expiration for distinct users in a future release.

Users can enter the shortened link in their browsers to be redirected to the orignal URL.

Usage

Build

go build -o url-shortener github.com/lixmal/url-shortener/cmd

Test

go test -v ./...

Run

GIN_MODE=release ./url-shortener

API

Shortening a URL

Request: POST to ∕api∕v1∕shorten∕<url to shorten>

Response success:

Code: 200
Body: JSON {"shortened_url":"http://host:port/<identifier>"}

Response on malformed request:

Code: 400
Body: JSON {"error":"<error message>"}

Response server error:

Code: 500
Body: JSON {"error":"<error message>"}

Looking up a URL

Request: GET to ∕api∕v1∕lookup∕<identifier>

Response success:

Code: 200
Body: JSON {"url":"<original url"}

Response on malformed request:

Code: 400
Body: JSON {"error":"<error message>"}

Response on unknown identifier:

Code: 404
Body: JSON {"error":"given identifier was not found"}

Accessing the original url through the shortened url

Request: GET to /<identifier>

Response success:

Code: 307
Header Location: <original url>

Response on malformed request:

Code: 400
Body: JSON {"error":"<error message>"}

Response on unknown identifier:

Code: 404

Limitations

The service currently stores all url <-> identifier mappings in memory, therefore all data is lost once the service is shut down.
Created shortened urls are valid forever. A time or consumption based deletion facility could be added in a future release.
No form of authz, authn or transport encryption is currently supported.
Identfiers are not cryptographically secure (= can be brute forced), don't create shortened urls with the mindset that they are secret.