challenge

A sample Crystal Kemal web application, utilising JSON Web Tokens (JWTs) for User Authentication. We use Auth0 to store our users, and to log them in on the frontend. We then exchange the login data for a JWT that we can pass around our app.

To Run:

Create a MySQL database and user with permissions for reads and writes etc.

The quickest way to do scaffold the database is to use the database migration tool, https://github.com/juanedi/micrate

To install the Micrate standalone, run:

$ brew tap juanedi/micrate
$ brew install micrate

After creating this database and installing Micrate, we need to tell Micrate to connect to the correct database. Set the following as an environment variable:

DATABASE_URL="mysql://[DB_USER]:[DB_PASS]@localhost:3306/[DB_NAME]"

Then from your working directory, run:

micrate create challenge

This will have created a file in /db/migrations titled 20170929011555_create_challenge.sql or similar. Open up that file and have it reflect the following:

-- +micrate Up
CREATE TABLE challenges (
  id BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  title VARCHAR(255),
  details TEXT,
  posted_by VARCHAR(255),
  created_at TIMESTAMP NULL,
  updated_at TIMESTAMP NULL
);

-- +micrate Down
DROP TABLE IF EXISTS challenges;

You can now run the micrate up command to structure the database.

Open up the src/challenger.cr file, and update the /login route with your own Auth0 app credentials:

  get "/auth/login" do |env|
    env.redirect "https://[YOUR_DOMAIN].auth0.com/login?client=[CLIENT_ID]"
  end

Next, you need to enter your Auth0 credentials in the file src/auth.cr:

uri = URI.parse("https://[YOUR_DOMAIN].auth0.com/oauth/token")

    request = HTTP::Client.post(uri,
      headers: HTTP::Headers{"content-type" => "application/json"},
      body: "{\"grant_type\":\"authorization_code\",\"client_id\": \"[CLIENT_ID]\",\"client_secret\": \"[CLIENT_SECRET]\",\"code\": \"#{id}\",\"redirect_uri\": \"http://localhost:6969/auth/callback\"}")

Finally, open up src/user.cr and add your Auth0 App Secret Key as the @@verify_key:

@@verify_key = "[CLIENT_SECRET]"

Now, run the shards install command from within the application directory, and execute:

crystal run src/challenger.cr

The app should be up and running and authenticating users through your Auth0 account.

Contributors

• rbnpercy Robin Percy - creator, maintainer