boobo94

How to fix warning about ECDSA host key

Remove the cached key for IP/DNS on the local machine:

ssh-keygen -R IP/DNS

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How Do I install or create or edit my own cron jobs?

To edit or create your own crontab file, type the following command at the UNIX / Linux shell prompt: $ crontab -e

Do I have to restart cron after changing the crontable file?

No. Cron will examine the modification time on all crontabs and reload those which have changed. Thus cron need not be restarted whenever a crontab file is modified.

Syntax of crontab (field description)

The syntax is:

boobo94

Here's what I did on a Ubuntu EC2:

A) Login as root using the keypairs

B) Setup the necessary users and their passwords with

$ sudo adduser USERNAME $ sudo passwd USERNAME

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# =====================[ EXPIRES CACHING ]=====================
<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType image/jpg "access 1 year"
ExpiresByType image/jpeg "access 1 year"
ExpiresByType image/gif "access 1 year"
ExpiresByType image/png "access 1 year"
ExpiresByType text/css "access 1 month"
ExpiresByType text/html "access 1 month"
ExpiresByType application/pdf "access 1 month"

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=====[Redirect if no https or www in a single redirect]=====

	RewriteCond %{HTTPS} off [OR]
	RewriteCond %{HTTP_HOST} !^www\.
	RewriteCond %{HTTP_HOST} ^(?:www\.)?(.+)$
	RewriteRule .* https://www.%1%{REQUEST_URI} [L,NE,R=301]

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RewriteEngine on
RewriteBase /
# Check if this is the noredirect query string
RewriteCond %{QUERY_STRING} (^|&)m=0(&|$)
# Set a cookie, and skip the next rule
RewriteRule ^ - [CO=mredir:0:www.website.com]

# Check if this looks like a mobile device
# (You could add another [OR] to the second one and add in what you
#  had to check, but I believe most mobile devices should send at

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<VirtualHost *:80>
        # without http or https
        ServerName URL_ADDRESS 

        RewriteEngine on
        RewriteCond %{HTTP_HOST} ^(.+)\.DOMAIN\.com$
        RewriteRule ^/(.*)$ https://%1.DOMAIN.com/$1 [R=301,L]

</VirtualHost>

boobo94

Install Mysql on Ubuntu

1. $ sudo apt-get update
2. $ sudo apt-get install mysql-server Mysql will ask for root password

Use mysql

$ mysql -u root -p Will ask for root password

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Useful commands

Show all databases \l+

Show all roles \du+

Show all tables \dt

Installing on Linux

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2. Design Pattern Questions

1.1. Answer: https://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller#Components - The model is the central component of the pattern. It is the application's dynamic data structure, independent of the user interface. It directly manages the data, logic and rules of the application. - A view can be any output representation of information, such as a chart or a diagram. Multiple views of the same information are possible, such as a bar chart for management and a tabular view for accountants. - The controller, accepts input and converts it to commands for the model or view.

2. Answer: https://en.wikipedia.org/wiki/Object-relational_mapping