Overview

A baseline Linux server is configured to serve a web app built with Flask. The server was updated and secured and also configured to serve data from a Postgresql database.

Configuration

The web server was configured with these steps;

1. Set up a new remote Linux instance on Amazon Lightsail

2. Create a Static IP address 18.219.29.211

3. Downloaded the private key file from Amazon as a *pem file.

4. Generated the Private key in Puttygen and saved it as a *ppk file.

5. Loaded the *ppk private keys to Putty and configured it to allow remote connection to the Amazon Linux instance.

6. Saved my session on putty to auto login

7. Run sudo apt-get update to list the required updates.

8. Run sudo apt-get upgrade to upgrade the software.

9. Create new user grader default password grader using sudo adduser grader

10. Create a sudoers.d for grader using sudo touch etc/sudoers.d/grader

11. Edit with nano sudo nano etc/sudoers.d/grader

12. Add grader ALL = (ALL) NOPASSWD:ALL into the file, this gives the grader user sudo access.

13. Make a .ssh folder inside the home directory of user grader, ``mkdir .ssh```

14. cd into .ssh and create a authorized_keys file using sudo touch authorized_keys

15. Copy the content of authorized_keys in the ubuntu user and paste into authorized_keys in grader user, also make sure .ssh and authorized_keys owner and group is grader. This allows the grader to login with ssh.

16. Change file permissions on .ssh and .ssh/authorized_keys in grader user using chmod 700 and 644 respectively.

17. cd to etc/ssh, then use sudo nano sshd_config to change ssh port from 20 to 2200.

18. Deny incoming request with sudo ufw default deny incoming

19. Allow outgoing connection with sudo ufw default allow outgoing

20. Change ssh from 22 to 2200 with sudo ufw allow 2200/tcp

21. Use sudo ufw allow www to set HTTP to port 80

22. Use sudo ufw allow 123/tcp to set NTP to port 123

23. sudo ufw enable to enable the firewall

24. Add custom TCP in the Amazon Lightsail account with TCP 2200

25. Restart linux instance and change port on putty to 2200, then log in again.

26. Install Apache with sudo apt-get install apache2

27. Go to 18.219.29.211 to check if apache is working

28. Run sudo apt-get install libapache2-mod-wsgi

29. Run sudo apt-get install postgresql

30. Enabled automatic update with sudo dpkg-reconfigure --priority=low unattended-upgrades

Configuring the database

1. run sudo su postgres to switch to the postgres user.

2. type psql to change to the Postgresql terminal.

3. create a new database called catalog with CREATE DATABASE catalog;

4. create user CREATE USER catalog WITH PASSWORD 'catalog';

5. grant privileges with GRANT ALL PRIVILEGES ON DATABASE catalog TO catalog;

Configuring Apache2

1. installed mod-wsgi with sudo apt-get install libapache2-mod-wsgi

2. edited /etc/apache2/sites-enabled/000-default.conf file by adding WSGIScriptAlias / /var/www/FlaskApp2/flaskapp2.wsgi before the ending <VirtualHost *:80> block.

3. created a FlaskApp2.conf file with sudo nano /etc/apache2/sites-available/FlaskApp.conf and added the following block of code to it;

  <VirtualHost *:80>
          ServerName 18.219.29.211
          ServerAdmin ezeh.chike
          WSGIScriptAlias / /var/www/FlaskApp2/flaskapp2.wsgi
          <Directory /var/www/FlaskApp2/FlaskApp2/>
                  Order allow,deny
                  Allow from all
          </Directory>
          Alias /static /var/www/FlaskApp2/FlaskApp2/static
          <Directory /var/www/FlaskApp2/FlaskApp2/static/>
                  Order allow,deny
                  Allow from all
          </Directory>
          ErrorLog ${APACHE_LOG_DIR}/error.log
          LogLevel warn
          CustomLog ${APACHE_LOG_DIR}/access.log combined
  </VirtualHost>

4. resarted apache2 with sudo apache2ctl restart

Deploying the Flask app

1. installed git with sudo apt-get install git

2. intalled python and all the app dependencies.

3. cloned the catalog app with git clone https://github.com/chikeezeh/Project_Item_Catalog.git

4. checked out the linux branch from the repo with sudo git checkout linux

5. Changed the ownership of all the files in the project with chown grader:grader *

6. arranged my folder structure as shown in this article

7. run python database_setup.py to create the database

8. run python populate_database.py to populate the database

9. put the following code in the flaskapp2.wsgi file ;

#!/usr/bin/python
import sys
import logging
logging.basicConfig(stream=sys.stderr)
sys.path.insert(0, "/var/www/FlaskApp2/")

from FlaskApp2 import app as application
application.secret_key = 'Add your secret key'

10. restart apache and go to 18.219.29.211 to launch the app.

Resources

https://www.digitalocean.com/community/tutorials/how-to-deploy-a-flask-application-on-an-ubuntu-vps

https://suhas.org/sqlalchemy-tutorial/

https://www.postgresql.org/docs/9.1/static/sql-grant.html