Linux Server Configuration

Fron a baseline installation of a AWS Ubuntu Server we prepare it to host a web application learning how to access, secure, and perform the initial configuration of a bare-bones Linux server. Also we install and configure a database server, and deploy a Items Project application onto it.

Getting Started

This project use a Amazon Lightsail Ubuntu Server to host an application. Here some information to access the host.

• IP Address: 18.204.17.121
• SSH port: 2200
• URL: http://18.204.17.121.xip.io/category

Prerequisites

To deploy this application in your own AWS sistem you will need:

• Amazon Web Services account
• Ubuntu Linux Server instance on Amazon Lightsail

Installing and Running

1. Update all currently installed packages.

     $ sudo apt update && sudo apt upgrade
   

2. Change the SSH port from 22 to 2200 and forbid root access.

     $ sudo vi /etc/ssh/sshd_config
   

     $ sudo service ssh restart
   

3. Configure Lightsail firewall.

   Inside the Item-Cataglog-Server instance on Amazon Lightsail go to network. Then add rules for HTTP, TCP and NTP connections.

4. Configure UFW firewall to only allow incoming connections for SSH(2200), HTTP(80) and NTP(123).

   Deny all incoming:

     $ sudo ufw default deny incoming
   

   Allow all outgoing:

     $ sudo ufw default allow outgoing
   

   Allow SSH(2200), HTTP(80) and NTP(123) ports:

     $ sudo ufw allow 2200/tcp
     $ sudo ufw allow 80/tcp
     $ sudo ufw allow 123/udp
   

   Enable firewall:

     $ sudo ufw enable
   

   Warning: When changing the SSH port, make sure that the firewall is open for port 2200 first, so that you don't lock yourself out of the server.

5. Go to the AWS Lightsail instance and match the UFW configuration with the firewall instance.

   After that you can logon server with:

     $ ssh -i ~/.ssh/LightsailDefaultKey.rsa [email protected] -p 2200
   

6. Install package to automatically manage updates

  $ sudo apt install unattended-upgrades
  $ sudo dpkg-reconfigure --priority=low unattended-upgrades

7. Give grader access.

   Create new user account on server:

     $ sudo adduser grader
   

   Give user sudo permission adding grader ALL=(ALL:ALL) ALL to the file:

     $ sudo visudo
   

   Create SSH key for user:

     $ ssh-keygen -f ~/.ssh/udacity_key.rsa
   

   Add key for authorized_keys file:

     $ sudo vi /home/grader/.ssh/authorized_keys
   

   Change the owner the permissions and restart the service:

     $ sudo chown -R grader:grader /home/grader/.ssh
     $ sudo chmod 700 /home/grader/.ssh
     $ sudo chmod 644 /home/grader/.ssh/authorized_keys
     $ sudo service ssh restart
   

   Now you can logon system with the new user:

     $ ssh -i ~/.ssh/udacity_key.rsa [email protected] -p 2200
   

8. Configure the local timezone to UTC.

   By default Ubuntu systems has the timezone seted to UTC. To confirm you can run the comand:

     $  sudo dpkg-reconfigure tzdata
   

9. Install and configure Apache to serve a Python3.

   Install Apache2:

     $  sudo apt install apache2
   

   Install Python 3 mod_wsgi to allow apache2 to serve python3:

     $  sudo apt-get install libapache2-mod-wsgi-py3
   

   Start Apache Server:

     $  sudo service apache2 start
   

10. Deploy the application.

    Install Github:

      $  sudo apt install git
    

    Create a directory named LinuxSever inside the Apache www path and get into it:

      $ sudo mkdir LinuxServer
    

    Clone the github application on apache www directory and move the LinuxServer.wsgi file to LinuxServer clone father:

      $  sudo git clone https://github.com/psaviott/LinuxServer.git
      $  sudo chown -R grader:grader LinuxServer/
    

    Create a .wsgi file

      $ sudo vi /var/www/LinuxServer/LinuxServer.wsgi
    

    Then paste the following code on a file:

      activate_this = '/var/www/LinuxServer/LinuxServer/venv3/bin/activate_this.py'
      with open(activate_this) as file_:
      exec(file_.read(), dict(__file__=activate_this))
    
      #!/usr/bin/python
      import sys
      import logging
      logging.basicConfig(stream=sys.stderr)
      sys.path.insert(0, "/var/www/LinuxServer/LinuxServer/")
      sys.path.insert(1, "/var/www/LinuxServer/")
    
      from catalog import app as application
      application.secret_key = 'super_secret_key'
    

    Install pip3:

      $  sudo apt install python3-pip
    

    Install create and activate a new virtual environment:

      $  sudo pip3 install virtualenv
      $  virtualenv -p python3 venv3
      $  sudo chown -R grader:grader LinuxServer/
      $  . venv3/bin/activate
    

    Install project dependencies and deactivate virtual environment:

      $  pip3 install -r /requirements.txt
      $  sudo apt install python3-psycopg2
      $  deactivate
    

11. Create a host on Apache.

    Edit wsgi.conf file:

      sudo vi /etc/apache2/mods-enabled/wsgi.conf
    

    Bellow WSGIPythonPath add this line:

      WSGIPythonPath /var/www/LinuxServer/LinuxServer/venv3/lib/python3.5/site-packages
    

    Create conf file:

      $  sudo vi /etc/apache2/sites-available/LinuxServer.conf
    

    Add this code on file:

      <VirtualHost *:80>
        ServerName 18.204.17.121
        ServerAlias ec2-18.204.17.121.compute-1.amazonaws.com
        WSGIScriptAlias / /var/www/LinuxServer/LinuxServer.wsgi
        <Directory /var/www/LinuxServer/LinuxServer/>
          Order allow,deny
          Allow from all
        </Directory>
        Alias /static /var/www/LinuxServer/LinuxServer/static
        <Directory /var/www/LinuxServer/LinuxServer/static/>
          Order allow,deny
          Allow from all
        </Directory>
        ErrorLog ${APACHE_LOG_DIR}/error.log
        LogLevel warn
        CustomLog ${APACHE_LOG_DIR}/access.log combined
      </VirtualHost>
    

    Enable host:

      $  sudo a2ensite catalog
    

    Reload Apache2:

      $  sudo service apache2 reload
    

12. Install and configure PostgreSQL.

    Install Python Packages:

      $  sudo apt install libpq-dev python-dev
    

    Install PostgreSQL:

      $  sudo apt install postgresql postgresql-contrib
    

    Inside psql create a new user with CREATEDB:

      # CREATE USER catalog WITH PASSWORD 'bill2012' CREATEDB;
    

    Create database:

      # CREATE DATABASE catalog WITH OWNER catalog
    

    Setup the database with:

      $ python /var/www/LinuxServer/LinuxServer/models.py
    

Deployment

• How to create a Amazon Lightsail Instance
• Connect to your instance with SHH private key
• How to configure UFW Firewall
• Flask Application with mod-wsgi
• Setup Apache2

Built With

• Amazon Lightsail
• Ubuntu Server
• Apache
• UFW
• PostgreSQL

Authors

• Philipe Saviott - psaviott

Acknowledgments

• Python3 documentation
• SSH Wikipedia
• Coordinated Universal Time Wikipedia
• Python mod_wsgi documentation