UrlShortener

Simple Url shortener in Elixir

For dev environments, it is recommended to use docker-compose, that references to a Postgres image, without requiring to install or use any existing database, leaving to docker to resolve this: docker-compose up sets up the environment with application on port 4000 and db on 5432 docker-compose down kills containers and cleans generated data (does not delete images).
For production environments, please point to a real database and change prod.exs config, then build and run the docker image.
To run tests, you need to set MIX_ENV environment variable to test, and then run mix test. If using docker-compose the command should be run inside the url_shortener container. Example already setting the env var for this execution:

MIX_ENV=test mix test

RESTful endpoint to generate a short hash representing a URL in the same API
Unique shortened url for each long URL
Shortened url expiration in 1 month without interaction
Dynamic parameters for existing and new parameters
All requests are tracked and all request headers are stored related to a single link, in a queryable fashion for analytics purpose.

One POST endpoint to create the URL and reply with a JSON containing the short key hash: /api/generate_short_url
One generic GET endpoint to access the long url through the hash created on POST endpoint /SHORT_HASH
Each POST of a new long url generates a new line in urls table, with a new short hash and validity to one month later. If the hash already exists it only updates the validity and returns the already created hash.
Each GET of an existing short hash will generate a new registry in url_metadata table, associated by the urls_id, so in order to query by a long url, for example, it is necessary to JOIN the two.
The metadata (request headers) was saved as a json map (jsonb structure in postgres, map in elixir), this is to allow flexibility in the request headers, as they may change a lot depending on the client.
Example query for the URL http://google.com/ see all the metadata generated: select metadata from url_metadata where full_url = 'http://google.com/'
Example query to select all requests hitting localhost, querying the JSON inside the table: select * from url_metadata WHERE metadata @> '{"host": "localhost:4000"}'

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