URL Shortener

To start your Phoenix server WITHOUT DOCKER COMPOSE:

Make sure that you don't have anything running on http://localhost:4000/
Source the .env file with the following command: source .env
Install dependencies with mix deps.get
Create and migrate your database with mix ecto.setup
Start Phoenix with mix phx.server or inside IEx with iex -S mix phx.server

Now you can visit localhost:4000 from your browser.

To start your Phoenix server WITH DOCKER COMPOSE:

Inside config/dev.exs change the hostname variable from localhostto db:

config :url_shortener, URLShortener.Repo,
  username: "postgres",
  password: "postgres",
  hostname: "db",   # <-------- UNCOMMENT THIS ONE
  #hostname: "localhost", # <-- COMMENT THIS ONE
  database: "url_shortener_dev",
  stacktrace: true,
  show_sensitive_data_on_connection_error: true,
  pool_size: 10

Make sure that you don't have anything running on http://localhost:4000/.
Make sure that port 5432 for POSTGRES is available
Run docker-compose up --build

To test the API endpoint, run the following command:

curl --location --request POST 'http://localhost:4000/api/gen_short_url' \
--header 'Content-Type: application/json' \
--data-raw '{
    "url": "https://www.google.com/"
}'