URL shortener

This is an example of how to create a URL shortener using:

• go-swagger as api Framework (OpenAPI 2.0)

• swagger-ui as frontend to publish documentation and provide a way to test APIs

• The apis logic need storage, that is passed as an interface to make easier change it

  • "github.com/boltdb/bolt" has been chosen as implementation since it is a quick key-value db

• prometheus is used to expose metrics under /metrics.

• dependencies are managed through go mod

• redirection is performed before hitting the API in the middleware

• error management is present but covers only most common cases

The code NOT autogenerated is included in the following packages/files:

• storage package (logic of storage)
• middlewares package (logic to redirect, prometheus)
• url_implementation package (logic of APIs)
• restapi/operation/configure_url_shortener.go file (linking pieces)
• swagger-ui/swagger.yml file (open-api definition, used to auto-generate the code)

The code autogenerated is NOT covered by tests, everything else has a coverage of ~ 80%

Development:

To add new Api modify swagger-ui/swagger.yml and run:

$swagger generate server -f ./swagger-ui/swagger.yml --exclude-main

Be aware, if you modify any autogenerated file it will be overwritten running such command.

Run test running: $go test ./...

Usage

To execute the server clone the repo, cd into it and run:

$go run ./cmd/url-shortener-server/main.go --port 35307

Navigate to localhost:35307/swagger-ui to visualise the UI and test APIs with a frontend Navigate to localhost:35307/metrics to check metrics, in particular url_redirected keeps track of redirection since last execution

There are three methods under /api:

• POST /api/url that accept in the json body the URL to make shorter
• GET /api/url/{shortURL} that returns the URL corresponding to shortURL
• DELETE /api/url/{shortURL} that delete the URL

Shortened URLs will be like short-abcdefghil and can be used as follows localhost:35307/short-abcdefghil

If you try to navigate to a shortened url that does not exist (es: localhost:35307/short-notExisting) you will be redirected to http://www.notfound.com