For the past few years cloud computing has made it’s stable grounds in every tech company. With the wider adoption of clouds, the better services and tools and the vast investments in automation and scalability, now it’s time to pay a bit more attention on the quality of the service and end user experience and multi-cloud is the strategic approach that will be the main driving power in 2018.
A great benefit of the cloud servers is the easy scaling of resources up and down. But after scaling to a larger cloud machine and acquiring more storage space, you should extend the Linux partitions on it as well as the file system, in order to use that new space.
The tricky part here comes when you want to resize the root partition and some old methods included taking your server off, mounting the storage drive on another Linux machine and resizing the partitions. That of course is very inconvenient in the case of a production server and there are better ways to resize your root partition without having to take it offline.
This tutorial is to guide you on setting up a simple, automatic MySQL database backups using mysqldump and a cron job.
This guide will help you setup a .htaccess file that restricts access to a page only to specific IP addresses. You might find that useful if you want to protect you web platform adminstration panel or some web tools like phpMyAdmin.
Containers are a great tool for any scale, from a small dev environment set up on a cloud machine to a large and scalable applications infrastucture. The main benefits are the lightweight, fast and easy setup and the plenty of flexibility.
In this tutorial we’ll take a look at LXD containers – one of the most popular at the moment, especially good for its “virtual machine” like containerization.
This tutorial is to guide you on setting up a simple, automatic MySQL database backups using mysqldump and a cron job.
You can use the ‘mysqldump’ that comes in any standard MySQL installation to do a database dump from the shell. To backup the ‘exampledb’ database to a file do:
mysqldump -uroot -p exampledb > exampledb.sql
Note that there is no space between the ‘-u’ switch and the user (root). With the ‘-p’ switch and paramater after it the ‘mysqldump’ will prompt you to enter a password.
This command will output plain SQL queries in the exampledb.sql, but as they are text they can be compressed really good to save space. So to make a compressed backup, let’s do:
mysqldump -uroot -p exampledb | gzip > exampledb.sql.gz
You can use these commands to make manual backups of your databases. If you want to backup all databases on a server, use the ‘–all-databases’ switch instead of database name, like this:
mysqldump -uroot -p –all-databases| gzip > mysql_server.sql.gz
Now that you know how to make manual database backups, let’s automate them with a cron job. You must set up a cron job that calls the ‘mysqldump’ tool on a schedule.
First let’s make a directory for storing the backups:
mkdir /var/backups/mysql
As backups are more usefull when they provide history, let’s give the backup file with more meaningful name by adding the date and time when the backup was taken:
mysqldump -uroot -p exampledb | gzip > /var/backups/mysql/exampledb.$(date +”%Y_%m_%d_%I_%M”).sql.gz
To automate the backup process ‘mysqldump’ must have the user password inline, so it’s highly recommended to set up an additional database user specifically for backups.
Open a crontab editor:
crontab -e
and add the following line at the bottom:
0 1 * * * mysqldump -uroot -p exampledb | gzip > /var/backups/mysql/exampledb.$(date +”\%Y_\%m_\%d_\%I_\%M”).sql.gz
The “0 1 * * *” stands for a schedule on every 01:00 or everyday at one after midnight. The cron line format is “m h dom mon dow command”, where:
The ‘*’ symbol in any of these means “on every” minute, hour, day and so.
Saving the crontab will set your backup on schedule and you are good to go.
Ufw or ‘uncomplicated firewall’ is a really nice tool that allows you to easily manage ‘iptables’ firewall in Linux with a bit more user friendly frontend instead of ‘iptable’ chains and rules.
It’s included in the most recent version of Debian and Ubuntu and we’ll start with a simple example – how to open or restrict SSH access to your cloud server.
To allow the SSH port:
ufw allow ssh
or
ufw allow 22/tcp
This will open the SSH port ( TCP 22 ) to the entire world.
Your cloud server is a public machine and you might want to protect it a bit better than being open to the whole Internet. To restrict the SSH access from only one IP address you can do:
ufw allow from your_ip_address to any port 22
for example
ufw allow from 78.130.176.1 to any port 22
You can also allow SSH access to you server from a range of addresses using the network slash notation:
ufw allow from 78.130.176.0/24 to any port 22
Before we are ready to go with your new firewall setup with ‘ufw’ we can check if it’s enabled by:
ufw status
and eventually if you get “status: inactive” enable it:
ufw enable
Get updates on cloud server security topics by following CloudBalkan.
An easy way to search for a word within directory contents is the ‘rgrep’ command:
rgrep “word“ /some/directory
If you don’t have the rgrep command installed on your distribution, you can use grep with the following flags:
grep -rnw “word” /some/directory
Example:
grep -rnw “Failed password” /var/log/auth.log
will list you all unsuccessful login attempts on your machine.
tar czf target-filename -N “8 hours ago” source-directory
tar czf /var/backup/archive.tar.gz -N “1 day ago” /var/www
In this tutorial we will give a quick instruction on downloading and installing phpMyAdmin from the source on a general setup.
phpMyAdmin is a popular web based MySQL management environment used by many developers. On popular distributions you can quickly install phpMyAdmin using package managers. This tutorial focuses on the installation from the source files when installing with package manager is not applicable.
cd /usr/share
wget https://files.phpmyadmin.net/phpMyAdmin/4.6.5.2/phpMyAdmin-4.6.5.2-english.tar.gz
tar xzf phpMyAdmin-4.6.5.2-english.tar.gz
mv phpMyAdmin-4.6.5.2-english phpmyadmin
chmod -R 0755 phpmyadmin
In order to install phpMyAdmin you might need administrative priviledges on your server as well as administator user for the MySQL database server.
Our recommended location for installing phpMyAdmin is ‘/usr/share’, so we start with:
cd /usr/share
Download the latest version of phpMyAdmin from the official site (https://www.phpmyadmin.net/):
wget https://files.phpmyadmin.net/phpMyAdmin/4.6.5.2/phpMyAdmin-4.6.5.2-english.tar.gz
and extract the files from the archive:
tar xzf phpMyAdmin-4.6.5.2-english.tar.gz
rename the folder:
mv phpMyAdmin-4.6.5.2-english phpmyadmin
change permissions:
chmod -R 0755 phpmyadmin
The last step to enable access to the phpMyAdmin is to add an alias to the folder in the Apache2 configuration.
To do it either edit the apache2.conf or add a new ‘phpmyadmin.conf’ file in the Apache2 configuration folder.
To add an alias, you must include the following lines in your Apache2 configuration:
Alias /phpmyadmin “/usr/share/phpmyadmin/”
<Directory “/usr/share/phpmyadmin/”>
Order allow,deny
Allow from all
Require all granted
</Directory>
After changing the configuration you must restart the Apache2 service:
RHEL / CentOS:
service httpd restart
Debian / Ubuntu:
service apache2 restart
With that your phpMyAdmin should be ready to use and accessible at your server address – “/phpmyadmin”.