/aws_lightsail_config_for_flask_python3

A aws lightsail configuration for flask and python 3 using postgresql. Project 6 from Udacity full stack nanodegree course.

Deploy of a flask app with postgres in aws lightsail

This project is a requirement of Udacity fullstack nano degree.

Step by Step Guide

Create an aws lightsail instance

Create a key pair (in your local machine)

I'm using gitbash in a windows machine. In gitbash prompt:

$ ssh-keygen

Choose file to save the key: /c/Users/<YOUR_WINDOWS_USERNAME>/.ssh/my_key

Create a new user (in aws console)

  • In Networking (aws panel) set another rule in firewall: -- Application = Custom -- Protocol = TCP -- Port = 2200

Thanks to CharInt: https://askubuntu.com/questions/1019891/connecting-to-amazon-lightsail-ubuntu-server-using-different-ssh-port)

  • Login in aws ssh console and type the following:
$ sudo adduser grader
$ sudo touch /etc/sudoers.d/grader
$ sudo nano /etc/sudoers.d/grader
  • Paste in grader file the following: grader ALL=(ALL:ALL) ALL
  • CTRL+O (save), ENTER (confirm), CTRL+X (exit nano) User grader have sudo privilegies now! Let's authorize grader to do remote login. In aws ssh:
$ su - grader
$ mkdir .ssh
$ sudo touch .ssh/authorized_keys
$ sudo nano .ssh/authorized_keys
  • Copy the public key generated on your local machine to this file
  • CTRL+O (save), ENTER (confirm), CTRL+X (exit nano)
  • Again, in aws console:
$ sudo chown -R  grader.grader /home/grader/.ssh
$ sudo chmod  700 /home/grader/.ssh
$ sudo chmod 600 /home/grader/.ssh/authorized_keys
$ ls -als .ssh/

Must print:

4 drwx------ 2 grader grader 
4 drwxr-xr-x 4 grader grader 
4 -rw------- 1 grader grader

Now, let's restart ssh and change its port to 2200:

$ sudo service ssh restart
$ sudo nano /etc/ssh/sshd_config
  • Change Port to 2200
  • CTRL+O (save), ENTER (confirm), CTRL+X (exit nano)
$ sudo service sshd restart
$ sudo service ssh restart

You can login with grader from your windows machine using gitbash now:

$ ssh grader@54.160.19.10 -p 2200 -i ~/.ssh/my_key

Here 54.160.19.10 must be change to your Public IP. We change the usual ssh port to 2200.

UPDATE and UPGRADE

Logged as grader:

$ sudo apt-get update
$ sudo apt-get upgrade

Disable root login

Logged as grader:

$ sudo vim /etc/ssh/sshd_config
  • Change PermitRootLogin to no
  • CTRL+O (save), ENTER (confirm), CTRL+X (exit nano)

Configure FIREWALL

Logged as grader:

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

Configure UTC TIME_ZONE

Logged as grader:

$ sudo dpkg-reconfigure tzdata

Install APACHE 2

Logged as grader:

$ sudo apt-get install apache2
$ sudo apt-get install libapache2-mod-wsgi-py3 python3-dev

Enter in your navigator with YOUR_PUBLIC_IP_ADDRESS (Mine is 54.160.19.10) to test if apache works fine.

Install Python 3 requirements

Logged as grader:

$ sudo apt-get install python3-pip
$ sudo python3 -m pip install --upgrade pip
$ pip3 install <PYTHON PACKAGES>

The necessary python packages for this project are flask, sqlalchemy and psycopg2. The last one have some problems because dependencies. To solve this:

$ sudo apt-get install libpq-dev python3-dev 
$ pip3 install psycopg2

Thanks Muhammad Taqi: https://stackoverflow.com/questions/28253681/you-need-to-install-postgresql-server-dev-x-y-for-building-a-server-side-extensi)

Install and Config POSTGRESQL

Logged as grader:

$ sudo apt-get install postgresql
$ sudo su - postgres
(postgres)$ psql
postgres=# CREATE DATABASE grader;
postgres=# CREATE USER grader;
postgres=# ALTER ROLE grader WITH PASSWORD 'password';
postgres=# GRANT ALL PRIVILEGES ON DATABASE grader TO grader;
postgres=# \q
(postgres)$ logout

Now, your have a grader database and a grader user tiwh all privileges on this database.

Clone your Flask App

Logged as grader:

$ sudo apt-get install git
$ cd /var/www
$ sudo mkdir FlaskApp
$ cd FlaskApp
$ git clone https://github.com/leandrocl2005/restaurant_python3_udacity.git
$ sudo mv ./restaurant_python3_udacity ./FlaskApp
$ cd FlaskApp
$ sudo nano config.py

Change DATABASE_URL to 'postgresql://grader:password@localhost/grader'

$ sudo nano app.py

Remove threaded=False in line 138.

Create your Apache configuration file

Logged as grader:

$ sudo nano /etc/apache2/sites-available/FlaskApp.conf

Copy and past the following configurations:

<VirtualHost *:80>
        ServerName 54.160.19.10
        ServerAdmin leandrocl2005@yahoo.com
        ServerAlias 54.160.19.10.xip.io
	WSGIScriptAlias / /var/www/FlaskApp/flaskapp.wsgi
	<Directory /var/www/FlaskApp/FlaskApp/>
		Order allow,deny
		Allow from all
	</Directory>
	Alias /static /var/www/FlaskApp/FlaskApp/static
	<Directory /var/www/FlaskApp/FlaskApp/static/>
		Order allow,deny
		Allow from all
	</Directory>
	ErrorLog ${APACHE_LOG_DIR}/error.log
	LogLevel warn
	CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

Create wsgi configuration file

Logged as grader:

$ cd /var/www/FlaskApp
$ sudo nano flaskapp.wsgi

Copy and past the following code:

#!/usr/bin/python3
import sys
import logging

logging.basicConfig(stream=sys.stderr)
sys.path.insert(0,"/var/www/FlaskApp/FlaskApp")

from app import app as application
application.secret_key = 'super secret key'

Restart and reload Apache:

$ sudo service apache2 restart
$ sudo service apache2 reload

Test your flask app

Enter in your navigator with YOUR_PUBLIC_IP_ADDRESS.xip.io (Mine is 54.160.19.10.xip.io) to test if apache works fine. If something works bad, logged as user you can check the apache error.log file:

sudo tail -f /var/log/apache2/error.log

Thanks