Ubuntu 16.04 PHP7 setup for Craft CMS

1) Get the latest available packages

sudo apt-get update

2) Install PHP7 and relevant extensions

Core PHP:
sudo apt-get install php7.0-fpm php7.0-cli php7.0-common php7.0-curl

Extensions needed for Craft:
sudo apt-get install php7.0-mysql php7.0-mbstring php7.0-mcrypt php-imagick php7.0-xml

breakdown: 
 - php7.0-mysql, for php to interact with the mysql database
 - php7.0-mbstring, for managing non-ASCII strings
 - php7.0-mcrypt, for data encryption and decryption
 - php-imagick, for image transforms
 - php7.0-xml, you can run craft without this one, but it would set off an errors when trying to connect asset sources to AWS s3
 
Install Composer:
sudo apt-get install composer

Composer is the php package manager, needed install phpdotenv, which we need to manage sensitive credentials in a multi-environment setup.

3) Install other craft Dependencies:

sudo apt-get install git nginx mysql-server

breakdown: 
 - git, needed to clone code from remote repo to the server.
 - nginx, webserver. I prefer nginx to apache due to the more readable syntax.
 - mysql-server, needed for database migration tasks. Even if you end up hosting your DB on another instance (i.e. AWS RDS), you still need this on your EC2 instance to interact with the other server.
 
4) Add a new Linux user for deployments and set it to the same user group used by php

sudo adduser deploy
sudo groupadd web
sudo usermod -a -G web deploy
sudo usermod -a -G web www-data

5) Give the new user Sudo privileges

sudo visudo

After the line: 
# User privilege specification
root ALL=(ALL:ALL) ALL

Add:
deploy ALL=(ALL:ALL) ALL

6) Configure nginx

sudo nano /etc/nginx/sites-available/your_site_name

paste in: 

server {
  listen   80;
  listen   [::]:80;

  root /var/www/your_project/current/public;
  index index.php index.html index.htm;

  server_name ip_or_url_to_your_server;

  location / {
    try_files $uri $uri/ @rewrites;
  }

  location @rewrites {
    rewrite ^(.*) /index.php?p=$1 last;
  }

  location ~ \.php$ {
    try_files $uri =404;
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_pass unix:/run/php/php7.0-fpm.sock;
    fastcgi_index index.php;
    include fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
  }

  expires off;
  error_page 404 /index.php;
  client_max_body_size 300M;
}

enable the config with a symbolic link:

sudo ln -s /etc/nginx/sites-available/your_site_name /etc/nginx/sites-enabled/your_site_name

restart nginx to load the new config:

sudo service nginx restart