Linux-Server-Configuration

Part of Udacity's Full Stack Web Developer Course

Server Configuration

• Public IP: 13.127.198.27
• Port: 2200

you can access this application at below links

• http://13.127.198.27/
• http://ec2-13-127-198-27.ap-south-1.compute.amazonaws.com/
• http://13.127.198.27.xip.io (This DNS name is required to add oauth to our application since google cannot accept IP address only for authentication. Visit this link for more info about xip.io)

Get Started

To complete this project, you'll need a Linux server instance. We recommend using Amazon Lightsail for this. If you don't already have an Amazon Web Services account, you'll need to set one up. Once you've done that, here are the steps to complete this project.

Step 1: Get your server

• Login into Amazon Lightsail
• Once you are login into the site, click Create instance.
• Choose Linux/Unix platform, OS Only and Ubuntu 16.04 LTS.
• Click the Create button to create the instance.
• Wait for the instance to start up.

Step 2: SSH into your Server

• Download private key from the SSH keys section in the Account section on Amazon Lightsail.
• Create a new file named lightsail_key.rsa under ~/.ssh folder on your local machine
• Copy and paste content from downloaded private key file to lightsail_key.rsa
• Set file permission as owner only : $ chmod 600 ~/.ssh/lightsail_key.rsa
• SSH into the instance: $ ssh -i ~/.ssh/lightsail_key.rsa ubuntu@13.127.198.27

Step 3: Secure your server

Update all currently installed packages

• Run sudo apt-get update to update packages
• Run sudo apt-get upgrade to install new versions of packages
• check for future updates: sudo apt-get dist-upgrade

Change the SSH port from 22 to 2200

• Run sudo nano /etc/ssh/sshd_config to edit the mentioned file
• Change the port number from 22 to 2200.
• Restart SSH: sudo service ssh restart.

Configure the Uncomplicated Firewall

• Run $ sudo ufw status to check firewall status
• Run $ sudo ufw default deny incoming to set default firewall to deny all incomings
• Run $ sudo ufw default allow outgoing to set default firewall to allow all outgoings
• Run $ sudo ufw allow 2200/tcp to allow incoming TCP packets on port 2200
• Run $ sudo ufw allow www to allow incoming TCP packets on port 80
• Run $ sudo ufw allow 123/udp to allow incoming UDP packets on port 123
• Run$ sudo ufw deny 22 to close port 22
• Run $ sudo ufw enable to enable firewall
• Run $ sudo ufw status to check current firewall status
• Update the firewall configuration on Amazon Lightsail website under Networking. Delete default SSH port 22 and add port 80, 123, 2200
• Open a new terminal and you can now ssh in via the new port 2200:
  $ ssh -i ~/.ssh/lightsail_key.rsa ubuntu@13.127.198.27 -p 2200

Step 4: Give grader access

Create a new user account named

• login as ubuntu, add user: sudo adduser grader.

Give grader the permission to sudo

• Edits the sudoers file: sudo visudo.
• add below line after 'root ALL=(ALL:ALL) ALL'

  grader  ALL=(ALL:ALL) ALL
  

• save the file and exit

Create an SSH key pair for grader using the ssh-keygen tool

• Run ssh-keygen on the local machine:
• Enter file in which to save the key in the local directory ~/.ssh.Two files will be generated ( ~/.ssh/grader_key and ~/.ssh/grader_key.pub)
• Run cat ~/.ssh/grader_key.pub and copy the contents of the file
• Log in to the grader's virtual machine
• Create a new directory called ~/.ssh (mkdir .ssh) on the grader's virtual machine
• Run sudo nano ~/.ssh/authorized_keys and paste the content into this file, save and exit
• Give the permissions: chmod 700 .ssh and chmod 644 .ssh/authorized_keys
• Check in /etc/ssh/sshd_config file if PasswordAuthentication is set to no
• Restart SSH: sudo service ssh restart
• On the local machine, run: ssh -i ~/.ssh/grader_key -p 2200 grader@13.127.198.27.

Step 5: Prepare to deploy your project

Configure the local timezone to UTC

• Run $ sudo dpkg-reconfigure tzdata

Install and configure Apache to serve a Python mod_wsgi application

• Install Apache: $ sudo apt-get install apache2
• Go to http://13.127.198.27/, if Apache is working correctly, a Apache2 Ubuntu Default Page will show up
• Install the mod_wsgi package: $ sudo apt-get install libapache2-mod-wsgi python-dev
• Enable mod_wsgi: $ sudo a2enmod wsgi
• Restart Apache: $ sudo service apache2 restart

Install and configure PostgreSQL

• login as grader, Run sudo apt-get install postgresql to install postgresql

• PostgreSQL should not allow remote connections. In the /etc/postgresql/9.5/main/pg_hba.conf file, you should see:

  local   all             postgres                                peer
  local   all             all                                     peer
  host    all             all             127.0.0.1/32            md5
  host    all             all             ::1/128                 md5
  

• run sudo su - postgres

• Open PostgreSQL interactive terminal with psql

• Create the catalog user with a password and give them the ability to create databases:

  postgres=# CREATE ROLE catalog WITH LOGIN PASSWORD 'catalog';
  postgres=# ALTER ROLE catalog CREATEDB;
  

• Exit psql using \q.

• Switch back to the grader user: exit.

• login as grader and create a new Linux user called catalog: sudo adduser catalog

• Give to catalog user the permission to sudo. Run: sudo visudo.

• add below line under root ALL=(ALL:ALL) ALL grader ALL=(ALL:ALL) ALL to give sudo previliges to catalog user

  catalog  ALL=(ALL:ALL) ALL
  

• Save and exit using CTRL+X and confirm with Y.

• While logged in as catalog, create a database: createdb catalog.

• Exit psql: \q.

• Switch back to the grader user: exit.

Install git

• Run $ sudo apt-get install git
• Create dictionary: $ mkdir /var/www/catalog
• CD to this directory: $ cd /var/www/catalog
• Clone the catalog app: $ sudo git clone 'URL OF YOUR REPO' catalog
• Change the ownership: $ sudo chown -R ubuntu:ubuntu catalog/
• CD to /var/www/catalog/catalog
• Change file project.py to init.py: $ mv project.py __init__.py
• Change line app.run(host='0.0.0.0', port=8000) to app.run() in init.py file
• Create a new project on Google API Console and download client_scretes.json file
• Copy and paste contents of downloaded client_scretes.json to the file with same name under directory /var/www/catalog/catalog/client_secrets.json

Step 6: Final setup

Installing the required packages

• Install pip: $ sudo apt-get install python-pip
• Install the following packages:

   $ sudo pip install httplib2
   $ sudo pip install requests
   $ sudo pip install --upgrade oauth2client
   $ sudo pip install sqlalchemy
   $ sudo pip install flask
   $ sudo apt-get install libpq-dev
   $ sudo pip install psycopg2

Setup and enble a virtual host

• Create file: $ sudo touch /etc/apache2/sites-available/catalog.conf
• Add the following to the file:

   <VirtualHost *:80>
		ServerName 13.127.198.27
		ServerAdmin admin@13.127.198.27
		WSGIScriptAlias / /var/www/catalog/catalog.wsgi
		<Directory /var/www/catalog/catalog/>
			Order allow,deny
			Allow from all
			Options -Indexes
		</Directory>
		Alias /static /var/www/catalog/catalog/static
		<Directory /var/www/catalog/catalog/static/>
			Order allow,deny
			Allow from all
			Options -Indexes
		</Directory>
		ErrorLog ${APACHE_LOG_DIR}/error.log
		LogLevel warn
		CustomLog ${APACHE_LOG_DIR}/access.log combined
   </VirtualHost>

• Run $ sudo a2ensite catalog to enable the virtual host
• Restart Apache: $ sudo service apache2 reload

Configure .wsgi file

• Create file: $ sudo touch /var/www/catalog/catalog.wsgi
• Add content below to this file and save:

   #!/usr/bin/python
   import sys
   import logging
   logging.basicConfig(stream=sys.stderr)
   sys.path.insert(0,"/var/www/catalog/")
   sys.path.insert(1,"/var/www/catalog/catalog")

   from catalog import app as application
   application.secret_key = 'super_secret_key'

• Restart Apache: $ sudo service apache2 reload

Edit the database path

• Replace lines in __init__.py, database_setup.py, and data.py with engine = create_engine('postgresql://catalog:PASSWORD@localhost/catalog')

Disable defualt Apache page

• $ sudo a2dissite 000-defualt.conf
• Restart Apache: $ sudo service apache2 reload

Set up database schema

• Run $ sudo python database_setup.py
• Run $ sudo python lotsofitems.py
• Restart Apache: $ sudo service apache2 reload
• Now follow the link to http://13.127.198.27/ the application should be runing online

Use xip.io for setting DNS name to your IP Address in order to run your application smoothly.

Resources used

• Amazon Lightsail for creating ubuntu instance
• Google API Console
• Udacity
• Apache
• Github
• Postgresql
• xip.io for DNS