Authentication plugin for Genie.jl

The GenieAuthentication.jl package is an authentication plugin for Genie.jl, the highly productive Julia web framework. As such, it requires installation within the environment of a Genie.jl MVC application, allowing the plugin to install its files (which include models, controllers, database migrations, plugins, and other files).

First load the Genie.jl application, for example using

$> cd /path/to/your/genie_app

$> ./bin/repl

Alternatively, you can create a new Genie.jl MVC application (SearchLight.jl ORM support is required in order to store the user accounts into the database). If you are not sure how to do that, please follow the documentation for Genie.jl, for example at https://genieframework.com/docs/Genie/v5/tutorials/4-1--Developing_MVC_Web_Apps.html.

Next, add the plugin:

julia> ]

(MyGenieApp) pkg> add GenieAuthentication

Once added, we can use its install function to add its files to the Genie.jl app (required only upon installation):

julia> using GenieAuthentication

julia> GenieAuthentication.install(@__DIR__)

The above command will set up the plugin's files within your Genie.jl app (will create various files including new views, controllers, models, migrations, initializers, etc).

The main plugin file should now be found in the plugins/ folder within your Genie.jl app. It sets up configuration and registers routes.

HEADS UP

Make sure to uncomment out the /register routes in plugins/genie_authentication.jl if you want to provide user registration features.

They are disabled by default in order to eliminate the risk of accidentally allowing random users to create accounts and expose your application.

The plugin needs DB support to store user data. You will find a *_create_table_users.jl migration file within the db/migrations/ folder. We need to run it:

julia> using SearchLight

julia> SearchLight.Migration.up("CreateTableUsers")

This will create the necessary table.

HEADS UP

If your app wasn't already set up to work with SearchLight.jl, you need to add SearchLight.jl support first. Please check the Genie.jl documentation on how to do that, for example at https://genieframework.com/docs/Genie/v5/tutorials/4-1--Developing_MVC_Web_Apps.html#Connecting-to-the-database. This includes setting up a db/connection.yml and an empty migration table with create_migrations_table if it has not already been done.

Upon a successful login, the plugin will redirect the user to the :success route, which invokes AuthenticationController.success.

Now that we have a functional authentication system, there are two ways of enforcing authentication.

The authenticated!() function will enforce authentication - meaning that it will check if a user is authenticated, and if not, it will automatically throw an ExceptionalResponse and force a redirect to the :show_login route which displays the login form.

We can use this anywhere in our route handling code, for example within routes:

# routes.jl
using GenieAuthentication

route("/protected") do; authenticated!()
  # this code is only accessible for authenticated users
end

Or within handler functions inside controllers:

# routes.jl
route("/protected", ProtectedController.secret)

# ProtectedController.jl
using GenieAuthentication

function secret()
  authenticated!()

  # this code is only accessible for authenticated users
end

HEADS UP

If you're throwing an ExceptionalResponse as the result of the failed authentication, make sure to also be using Genie.Exceptions.

In addition to the imperative style of the authenticated!() function, we can also use the authenticated() function (no ! at the end) which returns a bool indicated if a user is currently authenticated.

It is especially used for adding dynamic UI elements based on the state of the authentication:

<div class="row align-items-center">
  <div class="col col-12 text-center">
    <% if ! authenticated() %>
    <a href="/login" class="btn btn-light btn-lg" style="color: #fff;">Login</a>
    <% end %>
  </div>
</div>

We can also use it to mimic the behaviour of authenticated!():

using Genie.Exceptions
using GenieAuthentication

# This function _can not_ be accessed without authentication
function index()
  authenticated() || throw(ExceptionalResponse(redirect(:show_login)))

  h1("Welcome Admin") |> html
end

Or to perform custom actions:

using GenieAuthentication

route("/you/shant/pass") do
  authenticated() || return "Can't touch this!"

  "You're welcome!"
end

You can create a user at the REPL like this (using stronger usernames and passwords though 🙈):

julia> using Users

julia> u = User(email = "admin@admin", name = "Admin", password = Users.hash_password("admin"), username = "admin")

julia> save!(u)

If the user was authenticated, check first with authenticated(), you can obtain the current user information with current_user().

using GenieAuthentication

route("/your/email") do
  authenticated() || return "Can't get it!"
  user = current_user()
  user.email
end