LBAW's framework
Introduction
This README describes how to setup the development environment for LBAW 2018/19. These instructions address the development with a local environment, i.e. on the machine (that can be a VM) without using a Docker container. Containers are used for PostgreSQL and pgAdmin, though.
The template was prepared to run on Linux 18.04LTS, but it should be fairly easy to follow and adapt for other operating systems.
- Installing the Software Dependencies
- Installing Docker and Docker Compose
- Setting up the Development repository
- Working with PostgreSQL
- Developing the project
- Publishing the image
- Laravel code structure
Installing the Software Dependencies
To prepare you computer for development you need to install some software, namely PHP and the PHP package manager composer.
We recommend using an Ubuntu distribution that ships PHP 7.2 (e.g Ubuntu 18.04LTS). You may install the required software with:
sudo apt-get install git composer php7.2 php7.2-mbstring php7.2-xml php7.2-pgsql
Installing Docker and Docker Compose
Firstly, you'll need to have Docker and Docker Compose installed on your PC. The official instructions are in Install Docker and in Install Docker Compose. It resumes to executing the commands:
# install docker-ce
sudo apt-get update
sudo apt-get install apt-transport-https ca-certificates curl software-properties-common
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
sudo apt-get update
sudo apt-get install docker-ce
docker run hello-world # make sure that the installation worked
# install docker-compose
sudo curl -L https://github.com/docker/compose/releases/download/1.18.0/docker-compose-`uname -s`-`uname -m` -o /usr/local/bin/docker-compose
sudo chmod +x /usr/local/bin/docker-compose
docker-compose --version # verify that you have Docker Compose installed.
Setting up the Development repository
You should have your own repository and a copy of the demo repository in the same folder in your machine. Then, copy the contents of the demo repository to your own.
# Clone the group repository (lbaw18GG), if not yet available locally
# Notice that you need to substitute GG by your group's number
git clone https://git.fe.up.pt/lbaw/lbaw18/lbaw18GG.git
# clone the LBAW's project skeleton
git clone https://git.fe.up.pt/lbaw/template-lbaw.git
# remove the Git folder from the demo folder
rm -rf template-lbaw/.git
# preserve existing README.md
mv template-lbaw/README.md template-lbaw/README_lbaw.md
# goto your repository
cd lbaw18GG
# make sure you are using the master branch
git checkout master
# copy all the demo files
cp -r ../template-lbaw/. .
# add the new files to your repository
git add .
git commit -m "Base laravel structure"
git push origin master
At this point you should have the project skeleton in your local machine and be ready to start working on it. You may remove the template-lbaw demo directory, as it is not needed anymore.
Installing local PHP dependencies
After the steps above you will have updated your repository with the required Laravel structure from this repository. Afterwards, the command bellow will install all local dependencies, required for development.
composer install
Working with PostgreSQL
We've created a docker-compose file that sets up PostgreSQL9.4 and pgAdmin4 to run as local Docker containers.
From the project root issue the following command:
docker-compose up
This will start the database and the pgAdmin tool. The database's username is postgres and the password is pg!lol!2019.
You can hit http://localhost:5050 to access pgAdmin4 and manage your database. On the first usage you will need to add the connection to the database using the following attributes:
hostname: postgres
username: postgres
password: pg!lol!2019
Hostname is postgres instead of localhost since Docker composer creates an internal DNS entry to facilitate the connection between linked containers.
Developing the project
You're all set up to start developing the project. In the provided skeleton you will already find a basic todo list App, which you will modify to start implementing your own project.
To start the development server, from the project's root run:
# Seed database from the seed.sql file.
# Needed on first run and everytime the database script changes.
php artisan db:seed
# Start the development server
php artisan serve
Access http://localhost:8000 to see the App running.
Publishing your image
You should keep your git's master branch always functional and frequently build and deploy your code. To do so, you will create a Docker image for your project and publish it at docker hub. LBAW's production machine will frequently pull all these images and make them available at http://lbaw18GG.lbaw-prod.fe.up.pt/.
BTW, this demo repository is available at http://demo.lbaw-prod.fe.up.pt/. Make sure you are inside FEUP's network or are using the VPN.
First thing you need to do is create a docker hub account and get your username from it. Once you have a username, let your Docker know who you are by executing:
docker login
Once your Docker is able to communicate with the Docker Hub using your credentials, configure the upload_image.sh script with your username and the image name. Example configuration:
DOCKER_USERNAME=johndoe # Replace by your docker hub username
IMAGE_NAME=lbaw18GG # Replace by your lbaw group name
Afterwards, you can build and upload the docker image by executing that script from the project root:
./upload_image.sh
You can test the image locally by running:
docker run -it -p 8000:80 -e DB_DATABASE="lbaw18GG" -e DB_USERNAME="lbaw18GG" -e DB_PASSWORD="PASSWORD" <DOCKER_USERNAME>/lbaw18GG
The above command exposes your application on http://localhost:8000.
The -e argument creates environment variables inside the container, used to provide Laravel with the required database configurations.
Note that during the build process we adopt the production configurations configured in the .env_production file. You should not add your database username and password to this file. The configuration will be provided as an environment variable to your container on execution time. This prevents anyone else but us from running your container with your database.
Finally, note that there should be only one image per group. One team member should create the image initially and add his team to the public repository at Docker Hub. You should provide your teacher the details for accessing your Docker image, namely, the Docker username and repository (DOCKER_USERNAME/lbaw18GG), in case it was changed.
Laravel code structure
In Laravel, a typical web request involves the following steps and files.
1) Routes
The web page is processed by Laravel's routing mechanism. By default, routes are defined inside routes/web.php. A typical route looks like this:
Route::get('cards/{id}', 'CardController@show');
This route receives a parameter id that is passed on to the show method of a controller called CardController.
2) Controllers
Controllers group related request handling logic into a single class. Controllers are normally defined in the app/Http/Controllers folder.
class CardController extends Controller
{
public function show($id)
{
$card = Card::find($id);
$this->authorize('show', $card);
return view('pages.card', ['card' => $card]);
}
}
This particular controller contains a show method that receives an id from a route. The method searches for a card in the database, checks if the user as permission to view the card, and then returns a view.
3) Database and Models
To access the database, we will use the query builder capabilities of Eloquent but the initial database seeding will still be done using raw SQL (the script that creates the tables can be found in resources/sql/seed.sql).
$card = Card::find($id);
This line tells Eloquent to fetch a card from the database with a certain id (the primary key of the table). The result will be an object of the class Card defined in app/Card.php. This class extends the Model class and contains information about the relation between the card tables and other tables:
/* A card belongs to one user */
public function user() {
return $this->belongsTo('App\User');
}
/* A card has many items */
public function items() {
return $this->hasMany('App\Item');
}
4) Policies
Policies define which actions a user can take. You can find policies inside the app/Policies folder. For example, in the CardPolicy.php file, we defined a show method that only allows a certain user to view a card if that user is the card owner:
public function show(User $user, Card $card)
{
return $user->id == $card->user_id;
}
In this example policy method, $user and $card are models that represent their respective tables, $id and $user_id are columns from those tables that are automatically mapped into those models.
To use this policy, we just have to use the following code inside the CardController:
$this->authorize('show', $card);
As you can see, there is no need to pass the current user.
5) Views
A controller only needs to return HTML code for it to be sent to the browser. However we will be using Blade templates to make this task easier:
return view('pages.card', ['card' => $card]);
In this example, pages.card references a blade template that can be found at resources/views/pages/card.blade.php. The second parameter contains the data we are injecting into the template.
The first line of the template states that it extends another template:
@extends('layouts.app')
This second template can be found at resources/views/layouts/app.blade.php and is the basis of all pages in our application. Inside this template, the place where the page template is introduced is identified by the following command:
@yield('content')
Besides the pages and layouts template folders, we also have a partials folder where small snippets of HTML code can be saved to be reused in other pages.
6) CSS
The easiest way to use CSS is just to edit the CSS file found at public/css/app.css.
If you prefer to use less, a PHP version of the less command-line tool as been added to the project. In this case, edit the file at resources/assets/less/app.less instead and keep the following command running in a shell window so that any changes to this file can be compiled into the public CSS file:
./compile-assets.sh
7) JavaScript
To add JavaScript into your project, just edit the file found at public/js/app.js.
-- André Restivo, Tiago Boldt, 03/2018