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https://www.digitalocean.com/community/tutorials/how-to-protect-ssh-with-fail2ban-on-ubuntu-14-04 Introduction

While connecting to your server through SSH can be very secure, the SSH daemon itself is a service that must be exposed to the internet to function properly. This comes with some inherent risk and creates a vector of attack for would-be assailants.

Any service that is exposed to the network is a potential target in this way. If you pay attention to application logs for these services, you will often see repeated, systematic login attempts that represent brute force attacks by users and bots alike.

A service called fail2ban can mitigate this problem by creating rules that can automatically alter your iptables firewall configuration based on a predefined number of unsuccessful login attempts. This will allow your server to respond to illegitimate access attempts without intervention from you.

In this guide, we'll cover how to install and use fail2ban on an Ubuntu 14.04 server.

Create user deploy

sudo adduser deploy
sudo adduser deploy sudo
visudo

deploy  ALL=(ALL) ALL
deploy ALL=(ALL) NOPASSWD: ALL (* ubuntu 18.04 *)

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	First, to create 4,000 MB of swap space:

	$ sudo dd if=/dev/zero of=/swapspace bs=1M count=4000
	4000+0 records in
	4000+0 records out
	4194304000 bytes (4.2 GB) copied, 5.92647 s, 708 MB/s

	======= Prolbem =================================================================================================================
	I have installed : ruby-2.0.0,postgres-9.2 , now in rails app when I execute:

	rake db:create , command I get:

	PG::InvalidParameterValue: ERROR: new encoding (UTF8) is incompatible with the encoding of the template database (SQL_ASCII)
	HINT: Use the same encoding as in the template database, or use template0 as template.
	: CREATE DATABASE "my_db_name" ENCODING = 'unicode'.......

	bin/rake:16:in `load'

	$ sudo su
	$ su postgres
	$ psql
	$ create database [database_name] with owner = deploy;
	$ \q
	$ exit
	$ exit
	$ psql --user deploy --password [database_name]
	$ \q

	Previously I’d only ever posted this in my ebook, WordPress Multisite 110.

	What people mean by this is the site they originally set to be seen at domain.com is no longer the one they want to use, but the one at (say) domain.com/temp or temp.domain.com. If this is what you’re wanting to due, it’s not impossible, but it is annoying and a little tricky. If you’re using the trick to give WP it’s own directory, these are not the directions you’re looking for. I haven’t written those out yet.

	First you have to go to Network Dashboard > Sites and edit the site you want to be the main site.

	Example.com using two

	This you want to to look like this:

	RewriteEngine On
	RewriteBase /
	RewriteRule ^index\.php$ - [L]

	# add a trailing slash to /wp-admin
	RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

	RewriteCond %{REQUEST_FILENAME} -f [OR]
	RewriteCond %{REQUEST_FILENAME} -d
	RewriteRule ^ - [L]

	sudo service mysql start

	if start: Job failed to start :
	https://www.digitalocean.com/community/tutorials/how-to-add-swap-on-ubuntu-14-04

	sudo adduser deploy

	sudo adduser deploy sudo
	su deploy

	sudo apt-get update
	sudo apt-get install lamp-server^ php5-gd libssh2-php

	sudo mysql -u root -p