How to add bulk IP addresses to DigitalOcean firewall ?

digitalocean

Trying to add bulk IP’s in DigitalOcean firewall? You are in the right place.

DigitalOcean cloud control panel UI doesn’t allow you to paste in multiple IP Addresses at once. That’s a good idea for a UI improvement.

In the meantime you can definitely do it via the API…… Read more

How to renew the SSL certificates for dovecot and postfix

Make a backup of the existing SSL key and certificate file

cd /etc/pki/dovecot
cp -a certs/dovecot.pem certs/dovecot.pem.old
cp -a private/dovecot.pem private/dovecot.pem.old

Create the new SSL certificate for two years:

openssl genrsa -out private/dovecot.pem 1024
openssl req -new -x509 -key private/dovecot.pem -out certs/dovecot.pem -days 730

Restart Dovecot and Postfix

sudo systemctl 
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How to display brightness level in i3status bar

I’ve been using Linux for a long time, but I was never entirely happy with the desktop environment options available. Until last year, Xfce was the closest to what I consider a good compromise between features and performance. Then I found i3, an amazing piece of software that changed … Read more

How to auto login in MySQL from a shell?

When you run MySQL commands MySQL, mysqlcheck, mysqdump and psql, psqldump, etc; they will pick username & password from this file if you do not provide them as argument (-u and -p). It can save you time.

Of course, if you specify username and password explicitly as part of the … Read more

How to install the latest git from source

git-install-latest-from-src.sh

wget https://github.com/git/git/archive/master.zip
unzip master.zip && rm master.zip
cd master
make configure
./configure --prefix=/usr
make install

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How to install PHP 7.1/7.2/7.3/7.4 in CentOS 7

Uncomment the required php version.

yum install -y http://rpms.remirepo.net/enterprise/remi-release-7.rpm
yum install -y yum-utils
# yum-config-manager --enable remi-php70
# yum-config-manager --enable remi-php71
# yum-config-manager --enable remi-php72
yum-config-manager --enable remi-php73
yum -y install php # php-mcrypt php-cli php-gd php-curl php-mysql php-ldap php-zip php-fileinfo 
php -v

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How to auto login in PostgreSQL from a shell?

When you run MySQL commands MySQL, mysqlcheck, mysqdump and psql, psqldump etc; they will pick username & password from this file if you do not provide them as argument (-u and -p). It can save you time.

Of course, if you specify username and password explicitly as part of the … Read more

fail2ban filters – custom rules using regexp

fail2ban

fail2Ban is a very handy tool to prevent a lot of unwanted traffic from consuming bandwidth on your servers. It’s a minimal and relatively simple IDS Type Tool that comes with some predefined filters to automatically lockout potentially dangerous or bandwidth-consuming type attacks.

1. creating a custom filter

/etc/fail2ban/filter.d/custom.conf
[Definition]
 
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Exploring the Logrotate Configuration

Logrotate is a system utility that manages the automatic rotation and compression of log files. If log files were not rotated, compressed, and periodically pruned, they could eventually consume all available disk space on a system.

Logrotate’s configuration information can generally be found in two places:

/etc/logrotate.conf: this file contains … Read more