Linux Server Configuration

This is the final project of Udacity Full Stack Nanodegree Course. It is particular to deploy Item-Catalog app on AWS Lightsail instance

Public IP: 52.59.198.48
SSH Port: 2200
URL: http://52.59.198.48
EC2 URL: "http://ec2-18-184-199-168.eu-central-1.compute.amazonaws.com"

Paths

This project consists of four paths:

A- Configure ports and Firewall

B- Secure my app server and the machine

C- Prepare my app for deploying

D- Export my Lighsail instance to EC2 instance

Path-A

1- Making sure the machine packages are up-to-date

Run sudo apt-get upgrade sudo apt-get update

2- Changing SSH port from 22 to 2200 sudo nano /etc/ssh/sshd_config

3- Add SSH port 2200 to AWS to allow getting into machine after Changing ports

4- Disable all coming connections to machine and allow all out going on Firewall

Run: sudo ufw default deny incoming sudo ufw default allow outgoing

5- Allow only needed ports to receive connections

Run: sudo ufw allow 2200/tcp ---> for SSH connections

Run: sudo ufw allow 80/tcp ---> for HTTP connections

Run: sudo ufw allow 123/udp --> for NTP connections

Run: sudo ufw enable

Run: sudo ufw status ---> To check allow ports

Path-B

1- Creating new user grader sudo adduser grader --force-badname

2- Add grader as sudoers

Run:sudo nano /etc/sudoers.d/grader

write inside: grader ALL=(ALL:ALL)ALL

3- Log in to new user sudo su - grader

4- Create key-pair encryption

Run: ssh-keygen ---> On local machine

5- Making new dir .ssh and file .ssh/authorized_keys to save public keys on Linux and secure them by passphase

Run: mkdir .ssh

Run: nano .ssh/authorized_keys

Run: cat ~/key.pub file ---> On local machine, Copy public keys and paste them inside .ssh/authorized_keys

Run: chmod 700 .ssh chmod then chmod 644 .ssh/authorized_keys

Run: sudo nano /etc/ssh/sshd_config ---> Check that Password Authentication is (no) to force Key-based Authentication

6- Now to log in as grader ssh -i ~/.ssh/secretkey -p 2200 grader@52.59.198.48

7- Disable ubuntu user sudo usermod --expiredate 1 ubuntu

8- Disallowing root login sudo nano /etc/ssh/sshd_config

change PermitRootLogin prohibit-password to PermitRootLogin no

Path-C

1- Configure the local timezone to UTC sudo dpkg-reconfigure tzdata

2- Install Apache weberver sudo apt-get install a2pache2

3- Install mod_wsgi sudo apt-get install libapache2-mod-wsgi python-dev

4- Enable mod_wsgi sudo a2enmod wsgi

5- Intall git, make clone directory, then clone Item-Catalog app from github as sub-directory called catalog

Run: sudo apt-get install git

Run: cd /var/www/

Run: mkdir catalog

Run: sudo git clone <URL> catalog

6- Rename webserver.py to init.py

Run: sudo mv webserver.py __init__.py

7- Setting up virtual environment to will keep the application and its dependencies isolated from the main system

Run: cd /var/www/catalog/catalog

Run: sudo apt-get install python-pip

Run: sudo pip install virtualenv

Run: sudo virtualenv venv or virtualenv --always-copy venv

Run: source venv/bin/activate

Run: sudo chmod -R 777 venv

8- Test python files to check them running successfully and install any missing modules

Run: sudo python __init__.py

Run: sudo python database_setup.py

Run: sudo python movieitems.py

Run: sudo python sqlalchemy oauth2client requests

Run: pip install <package name> ---> for any other missing modules

9- Create new virtual host for my application

Run: sudo nano /etc/apache2/sites-available/catalog.conf

Write inside:

   `<VirtualHost *:80>

  		ServerName 52.59.198.48

  		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>`

Run: sudo a2ensite catalog.conf ---> To enable VH

10- Create .wsgi file ---> This file runs the server

Run: cd /var/www/catalog

Run: sudo nano catalog.wsgi

Write inside:

 `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 = 'super_secret_key`

Restart Apache

Run:sudo service apache2 restart or sudo service apache2 reload

12- Install postgersql server

Run: sudo apt-get install postgresql

Run: sudo su - postgres ---> Log in as postgres adduser

Run: psql ---> Get into DB

13- Create new database user with limited permissions to catalog application database

Run: `CREATE USER catalog WITH PASSWORD "catalog";

         CREATE DATABASE catalog;`

Check no remote connection to DB

Run: sudo cat /etc/postgresql/9.5/main/pg_hba.conf

        `# 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`

14- Change DB in my app from SQLite to PSQL

Run:

   `sudo nano /var/www/catalog/catalog/__init__.py

    sudo nano /var/www/catalog/catalog/database_setup.py

    sudo nano /var/www/catalog/catalog/movieitems.py`

change engine=create_engine('sqlite:///movies.db')

to engine = create_engine('postgresql://catalog:catalog@localhost/catalog')

15- Run App

Run:

   `python /var/www/catalog/catalog/database_setup.py

    python /var/www/catalog/catalog/movieitems.py

    python /var/www/catalog/catalog/__init__.py`

16- Restart apache sudo service apache2 reload

17- Vist site IP: 52.59.198.48

18- Incase any errors appeared sudo tail -f /var/log/apache2/error.log

Path-D

Lightsail instance doesn’t support domain name which is mandatory for Google oauth2 sign in so we go to EC2

1- Going to snapshots on lightsail instance and create one

snapshot make a copy of all instance database

2- Export snapshot to Amazon EC2, launch it, and configure ports

3- Create new key pair

4- Adding URL to Authorized JavaScript origins on google credentials

5- Adding EC2 Domain to Google's authorized domain list

6- Update client_secrets file

Run: sudo nano /var/www/catalog/catalog/client_secrets

add EC2 URL to authorized JavaScript origins

check http://localhost:5000/gconnect is in redirect_uris

7- Change ServerName in catalog.wsgi to EC2 URL

8- Change client_secrets path in init.py files

  `CLIENT_ID = json.loads(
   open('/var/www/catalog/catalog/client_secrets.json', 'r').read())['web']['client_id']

   oauth_flow = flow_from_clientsecrets('/var/www/catalog/catalog/client_secrets.json', scope='')`

Error Handling

When installing psycopg2 module:

 `ImportError: No module named psycopg2`

Run: pip install psycopg2-binary

`Error: You need to install postgresql-server-dev-X.Y for building a server-side extension or libpq-dev for building a client-side application.`

Run:

      `sudo apt-get install postgresql

       sudo apt-get install python-psycopg2

       sudo apt-get install libpq-dev`

When installing flask

 `ImportError: No module named flask`

Run: sudo nano /etc/apache2/sites-available/catalog.conf

Add the following two lines before the "WSGIScriptAlias" line:

 `WSGIDaemonProcess catalog python-path=/var/www/FlaskApp:/var/www/  catalog/catalog/venv/lib/python2.7/site-packages

  WSGIProcessGroup catalog`

Restart Apache with service apache2 restart

Remove Rows from Items

1- log in to DB as postgres user sudo su - postgres

\l is used to show and listing all DBs

2- Switch to catalog user \c catalog

3- In case deleting categories we will face error: update or delete on table "category" violates foreign key constraint error that is because category table is foreign key for movive table.

This is called Cascade Delete Error

4- So we use command

   `DELETE FROM some_child_table WHERE some_fk_field IN (SELECT some_id FROM some_Table);  

    DELETE FROM some_table;`

In this project command is:

 `DELETE FROM movie WHERE category_id IN (SELECT 12 FROM category);

  DELETE FROM category where id=12;`

Third Party Resouces

AmrSalah10/Linux-Server-Configuration-Deploying

Linux Server Configuration

Paths

Path-A

Path-B

Path-C

Path-D

Error Handling

Remove Rows from Items

Third Party Resouces