Agora - Ouranos (Backend Implementation)

In ancient Greek, the word agora means a public open space for gathering. In a day in age where COVID-19 has prohibited physical gatherings, we, at Creative Labs, have created a platform for individuals to gather around: Agora. Agora is a collaborative canvas centered around community. We built it so that every individual can only contribute one stroke at a time with the hope that people would come together to build something amazing.

This repository is dedicated to the backend architecture of Agora which we dubbed after the sky titan Ouranos. Much like how the sky is an integral part of our lives that we all take for granted, our backend models a similar ideology. As the father of titans and the husband of Gaia (frontend), Ouranos was a fitting name to encompass the entirety of our backend.

For extensive documentation and implementation, checkout our wiki.

To see how to deploy on Oracle Cloud Infrastructure, checkout this wiki page

Getting Started - Locally

Our backend is hoisted completely with Oracle Cloud Infrastructure. Through our process we weren't able to find the best documentation on how to implement our backend infrastructure. Hopefully, the following guide will be able to help you run Ouranos locally.

We recommend using some sort of cloud infrastructure to view the full power of horizontal scalability. However, if you just want to get started the following guide might be a good place to start to understand sockets and postgres.

We utilize a .env file for security reasons and recommend you follow the same protocol.

Put the .env file in your root directory for your project

    cd agora-ouranos
    touch .env

Add the following to your .env file:

    DB_USER=<YOUR USERNAME HERE>        // by default our script, canvas_psql.sh, sets this to 'opc'
    DB_PWD=<YOUR PASSWORD HERE>
    DB_HOST=<PUBLIC IP OF DB HERE>      // if running locally then 127.0.0.1
    DB_NAME=canvas-db
    DB_PORT=5432                        // if unspecified postgres automatically ports to 5432

    REDIS_HOST=<PUBLIC IP HERE>         // if unbound, this is just the public IP or 127.0.0.1
    REDIS_PORT=6379                     // if unspecified redis automatically ports to 6379
    REDIS_PWD=<YOUR PASSWORD HERE>

** Note that in order to utilize Redis for multiple app servers, you will need a load balancer. See below for more details.

Obtain the Repository and Install Dependencies

Clone the repository:

    git clone https://github.com/UCLA-Creative-Labs/agora-ouranos.git
    cd agora-ouranos


Dependencies:

    Node.js
    yarn
    PostgreSQL
    Redis*

Install Dependencies:

    # Downloads NVM (for node.js)
    curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.3/install.sh | bash

    # Downloads YARN
    curl --silent --location https://dl.yarnpkg.com/rpm/yarn.repo | sudo tee /etc/yum.repos.d/yarn.repo
    sudo rpm --import https://dl.yarnpkg.com/rpm/pubkey.gpg

    # Sourcing the bash intializing script to export nvm to $PATH	
    source ~/.bashrc	

    # Switch to the correct node version	
    # Run node --version or npm --version to ensure its not 8.1	
    nvm install node	

    # Installs to node modules 	
    # express   => node.js framework	
    # postgres  => easily interface with postgres server	
    # nodemon   => watch changes to your node.js applications and update them
    # socket.io => connecting to client
    yarn install
    
* Only necessary if you want to run multiple node.js applciations

Initialize Database

We have a script to initialize a postgres server very quickly.

Intialize postgres database:

    bash canvas_psql.sh

Breakdown:
    - init postgres
    - start postgres
    - create a user (call it 'opc' or whatever you want to use in .env file)
    - set password for user (user currently is defaulted to ```opc``` but change it in the canvas_psql file to match .env)
    - create a database (call it canvas-db)
    - create a table called canvas_data

Initialize Redis

Only complete this step if you want to use multiple nodes and have a method for load balancing!!!

To load balance locally, follow this guide.

Install Redis:

    sudo yum install redis -y               // yum is for CentOS and RHEL operating systems
    sudo systemctl start redis.service
    sudo systemctl enable redis

    sudo systemctl status redis.service     // check the status for you redis service
    redis-cli ping                          // you should get the output 'PONG'

Usage

Time to get our app server working.

The following documentation is to show you how to start up a server and prove that it works.

Start your node.js development server:

    yarn start

Check out your localhost to see if app server is listening at port 3000:

    http://127.0.0.1:3000/

You should see something like this:

    Cannot /GET

Since we are using sockets, it makes sense that there is no '/GET' at the base of localhost:3000.

Congrats, you just spun up Ouranos locally!