Linux server configuration & web app deployment project
This is the fifth project for Udacity Fullstack Nanaodegree program, In this project I configured a Ubuntu linux server(Amazon lightsail instance) and deployed Restful web application that was developed earlier in the program Catalog Web App using Apache, Python Flask and PostgreSQL.
IP address for server - 18.217.114.9
Linux Server Configuration:
Spin up a linux server instance in Amazon Lightsail
Update installed packages
sudo apt-get update
sudo apt-get upgrade
Create new user and grant sudo permission
#create linux user
sudo adduser grader
#enter the passsword
#grant sudo permission
sudo touch /etc/sudoers.d/grader
#edit file to add this
grader ALL=(ALL) ALL
Key based authentication for new user
In your local machine, use command below to generate public private key pair
cd ~/.ssh
ssh-keygen
Copy the content of the .pub file and paste into the .ssh/authorized_keys file of user grader directory
#log in as grader user
sudo -su grader
#create .ssh/authorized_keys file and paste the contents
mkdir /home/grader/.ssh
touch /home/grader/.ssh/authorized_keys
nano /home/grader/.ssh/authorized_keys
#paste the content of the .pub file from the local machine into /.ssh/authorized_keys file
Disable remote login of the root user
sudo nano /etc/ssh/sshd_config
#set PermitRootLogin to no, and save the file
#restart ssh service
sudo service ssh restart
Change SSH access from port 22 to 2200
sudo nano /etc/ssh/sshd_config
change the line 'Port 22' to 'Port 2200', and save the file
Configure Uncomplicated Firewall
# close all incoming ports
sudo ufw default deny incoming
# open all outgoing ports
sudo ufw default allow outgoing
# open ssh on port 2200
sudo ufw allow 2200/tcp
# open http on port 80
sudo ufw allow 80/tcp
# open ntp on port 123
sudo ufw allow 123/udp
# turn on firewall
sudo ufw enable
Now you should be able to log in through ssh without a password
sudo ssh -vvv -i ~/.ssh/id_rsa grader@18.217.114.9 -p2200
Configure Local timezone to UTC
sudo dpkg-reconfigure tzdata
#choose 'None of the above' in the option and then select 'UTC'
Web server configuration and app deployment
Apace webserver and MOD-WSGI installation
sudo apt-get install apache2 libapache2-mod-wsgi
MOD-WSGI acts as a gateway to our web application. Anytime we receive a request to access our web application, Apache2 webserver will communicate to our webapp through MOD-WSGI
PostgreSQl installation and configuration
sudo apt-get install postgresql
By default postgreSQL is restricted to listening on localhost, we can confirm by looking at /etc/postgresql/9.5/main/pg_hba.config
#TYPE DATABASE USER ADDRESS METHOD
#"local" is for Unix domain socket connections only
local all all md5
#IPv4 local connections:
host all all 127.0.0.1/32 md5
#IPv6 local connections:
host all all ::1/128 md5
#Allow replication connections from localhost, by a user with the replication privilege.
#local replication postgres peer
#host replication postgres 127.0.0.1/32 md5
#host replication postgres ::1/128 md5
127.0.0.1/32 corresponds to local connections. we can leave as is.
Create postgres user and creating db for our catalog web app.
postgres creates a user 'postgres' by default while installation, we can use this user access to create a new catalog user and create catalog db for our web application.
#connect postgres as postgres user
sudo su - postgres
#create a new user 'catalogs' with password 'catalogs'
CREATE USER catalogs WITH PASSWORD 'catalogs'
#create a new DB named 'catalogs' by user 'catalogs'
CREATE DATABASE catalogs WITH OWNER catalogs;
now we have our 'catalogs' database ready and we need to reference it in our web application.
Web application install & config
first step is installing git and cloning our catalog web application
#Installing git
sudo apt-get install git
#cloning web application at this location
cd /var/www/catalog/catalog
sudo git clone https://github.com/ashokjain001/Item-catalog-web-app.git
Now we will set up virtual environment so that we can install other dependencies required by our project.
#Installing pip
sudo apt-get install python-pip
#Installing virtual env
sudo pip install virtualvenv
#Create new virtual environment
virtualenv venv
#Activating virtual environment
source venv/bin/activate
#Installing all the python packages and dependencies required by this project
pip install --upgrade -r requirements.txt
Configure web application to connect to the postgres catalogs database which we created instead of SQLite
#udpate catalog_db_user.py which converts the python class and converts into postgresql table to use posgres catalogs db
update this
engine = create_engine('sqlite:///catalogappwithuserslogin.db')
with
engine = create_engine('postgresql://catalogs:catalogs@localhost/catalogs')
#make same changes to lotsofcatalog.py which fills our catalogs db with data.
#make similar changes to __init__.py which contains code to run our application.
Configure Apache to serve the web application using MOD-WSGI
#create .wsgi file at this location
sudo nano /var/www/catalog/catalog.wsgi
Add the following line of code to your .wsgi config file
#!/usr/bin/python
import sys
import logging
logging.basicConfig(stream=sys.stderr)
sys.path.insert(0,"/var/www/catalog/")
from catalog import app as application
application.secret_key = 'Add your secret key'
Update the Apache configuration file to serve the web application with WSGI.
sudo nano /etc/apache2/sites-enabled/000-default.conf
Add following lines of code
<VirtualHost *:80>
ServerName 18.217.114.9
ServerAlias ec2-18-217-114-9.us-east-2.compute.amazonaws.com
ServerAdmin admin@18.217.114.9
WSGIDaemonProcess catalog python-path=/var/www/catalog/catalog:/var/www/catalog/catalog/$
WSGIProcessGroup catalog
WSGIScriptAlias / /var/www/catalog/catalog.wsgi
<Directory /var/www/catalog/catalog>
Order allow,deny
Allow from all
</Directory>
Alias /static /var/www/catalog/catalog/static
<Directory /var/www/catalog/catalog/static/>
Order allow,deny
Allow from all
</Directory>
ErrorLog ${APACHE_LOG_DIR}/error.log
LogLevel warn
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
After this step your application should be deployed.