[#6][#7] As a user, I can sign-in using my email and password | Front-end & back-end

[longnd]

Resolves #6, Resolves #7

What happened

• Implements the Sign-in feature: user can use a valid username & password to log in.
• Adds 2 new pipelines:
  • :ensure_auth - when applied on a route, the user must log in before accessing
  • :skip_after_auth - when applied on a route, the route will be skipped if the user already logged in and redirects the user to the dashboard page.

Insight

To authenticate the user, this PR uses the guardian package (Github). It provides:

• The EnsureAuthenticatedPlug to force the user to log in before accessing a route
• Some built-in methods to log in a user and get the current user. We need to implement some methods as required by Guardian in:
  

  elixir-gscraper/lib/gscraper/guardian/authentication.ex

  Lines 1 to 5 in 300a70e

  	defmodule Gscraper.Guardian.Authentication do
  	@moduledoc """
  	Implementation module for Guardian and functions for authentication.
  	"""
  	use Guardian, otp_app: :gscraper

• The ErrorHandler is also required by Guardian is implemented in:
  

  elixir-gscraper/lib/gscraper/guardian/error_handler.ex

  Lines 1 to 6 in 300a70e

  	defmodule Gscraper.Guardian.ErrorHandler do
  	@behaviour Guardian.Plug.ErrorHandler
  	use GscraperWeb, :controller
  	@impl Guardian.Plug.ErrorHandler

Proof Of Work

Screen.Recording.2021-09-12.at.10.13.41.mov

[hanam1ni]

Small comments, the rest LGTM 👍

[rosle]

👍