Install and Secure Redis on CentOS 7

Step 1 – Install and Enable Remi Repository

Firstly, we will add the Remi repository to the CentOS 7 system. The Remi repository provides the latest version of Redis package for our installation.

Before adding the Remi repository, let’s install the EPEL repository and yum utility packages.

sudo yum install epel-release yum-utils

Now add the Remi repository for CentOS 7 using the yum command below.

sudo yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm

After that, enable the ‘remi’ repository using the yum-config-manager tool as below.

sudo yum-config-manager --enable remi

The Remi repository has been added and enabled on the CentOS 7 system, check using the yum command Continue reading “Install and Secure Redis on CentOS 7” »

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Upgrade Debian 9 to Debian 10

Update ALL existing installed packages

Before you upgrade your Debian version to 10, you must apply all security patches and pending upgrades to Debian 9 itself Hence, Type the following apt command or apt-get command:

sudo apt update
sudo apt upgrade
sudo apt full-upgrade
sudo apt --purge autoremove

OR

sudo apt-get update
sudo apt-get upgrade
sudo apt-get full-upgrade
sudo apt-get --purge autoremove

Reboot the Debian 9.x stretch to apply the kernel and other updates: Continue reading “Upgrade Debian 9 to Debian 10” »

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Softether Auto Installer on CentOS/Debian/Ubuntu (Backward compatible edition)

Softether Auto Install Script for multi platforms updated version

  • Softether VPN server latest version v4.27-9666-beta-2018.04.21
  • Revised to last known stable version due to compilation error from their latest release
  • An open source VPN project from University of Tsukuba Japan

Centos 6 or 7 x64

  • Debian 8 (jessie) (Not compatible for Debian 9 (stretch) x64 – compilation error)
  • Ubuntu 14, 15, 16 x64 (Not compatible for Ubuntu 17 and 18 x64 – compilation error)

Instruction

Choose your desired platform folder

Download installer.sh using wget or transfer to your root directory using ftp Continue reading “Softether Auto Installer on CentOS/Debian/Ubuntu (Backward compatible edition)” »

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Configure DomainKeys- DKIM (OpenDKIM) with Postfix on CentOS 7

OpenDKIM is method to digitally sign & verify emails on the mail servers using public & private keys. In other words opendkim implements the DKIM (DomainKeys Identified Mail) standard for signing and verifying email messages on a per-domain basis. DomainKeys are implemented to reduce the chances of outgoing mails to be marked as SPAM.

In this post we will demonstrate how to install & configure DomainKeys with postfix (MTA) on CentOS 7, i am assuming Postfix is already installed with following domain and hostname.

Hostname = mail5.freshdaymall.com
Domain = freshdaymall.com

Step:1 Set EPEL Repository using below rpm command

OpenDKIM package is not available in the default yum repositories but available in CentOS 7 EPEL repositories

[root@mail5 ~]# rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

Step:2 Install OpenDKIM Package using yum

[root@mail5 ~]# yum install -y opendkim

Step:3 Run below Command to create keys

Execute the below command to create public & private keys under folder “/etc/opendkim/keys” Continue reading “Configure DomainKeys- DKIM (OpenDKIM) with Postfix on CentOS 7” »

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Ping behind proxy using httping

You can use utility httping for that. It sends a HEAD request (by default) to a web server and measures the time it took to get a response.

The utility is available through a number of repositories for different OS’es and Linux distros:

Ubuntu:

sudo apt install httping

Alpine:

sudo apk add httping

macOS with Homebrew:

brew install httping

How to use it:

httping -x 192.68.1.12:1080 -g http://google.com

Continue reading “Ping behind proxy using httping” »

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enable SNMP on Xen (XCP-NG) hypervisors

There are six steps to correctly configuring SNMP on your Citrix Xen hypervisor. These steps don’t require a system restart and are non-service affecting.

To start, we assume you’re running Xen v6.x or v7.x, and are logged into the Xen CLI as root.

1. Enable the SNMP daemon

Enable the snmpd daemon by typing-

chkconfig snmpd

2. Configure the SNMP service

Make a backup of the snmpd.conf file. The default snmpd.conf file contains a lot of useful documentation for more advanced implementations of SNMP.

# cp /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.backup

Continue reading “enable SNMP on Xen (XCP-NG) hypervisors” »

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How to find out the connected interface using linux command

Method 1

To find out the connected state of a network cable in Linux, just run:

$ cat /sys/class/net/enp5s0/carrier

Sample output:

1

If you got output as “1” (Number one), It means that the network cable is connected with the network card. Also, you can do this with the following command too:

$ cat /sys/class/net/enp5s0/operstate

Sample output: Continue reading “How to find out the connected interface using linux command” »

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Install LAMP on CentOS 7 with PHP 5.4/7.0/7.1/7.2/7.3/7.4

Preliminary Note

In this tutorial, I use the hostname server1.example.com with the IP p 192.168.0.100. These settings might differ for you, so you have to replace them where appropriate.

I will add the EPEL repo here to install latest phpMyAdmin as follows:

rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY*
yum -y install epel-release

To edit files on the shell, I’ll install the nano editor. If you prefer vi for file editing, then skip this step.

yum -y install nano

Installing MySQL / MariaDB

MariaDB is a MySQL fork of the original MySQL developer Monty Widenius. MariaDB is compatible with MySQL and I’ve chosen to use MariaDB here instead of MySQL. Run this command to install MariaDB with yum:

yum -y install mariadb-server mariadb

Then we create the system startup links for MySQL (so that MySQL starts automatically whenever the system boots) and start the MySQL server: Continue reading “Install LAMP on CentOS 7 with PHP 5.4/7.0/7.1/7.2/7.3/7.4” »

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Remove Node from Proxmox Cluster

Step 1 : Migrate all VMs to another active node

Migrate all VMs to another active node. You can use the live migration feature if you have a shared storage or offline migration if you only have local storage.

Step 2 : Display all active nodes

Display all active nodes in order identify the name of the node you want to remove Continue reading “Remove Node from Proxmox Cluster” »

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Add Geolocation to Graylog 2

The Graylog Map Widget is the plugin providing geolocation capabilities to Graylog. The plugin is compatible with Graylog 2.0.0 and higher, and it is installed by default, although some configuration is still required on your side. This section explains how to configure the plugin in detail.

In case you need to reinstall the plugin for some reason, you can find it inside the Graylog tarball in our downloads page. Follow the instructions in Installing and loading plugins to install it.

Configure the database

In first place, you need to download a geolocation database. We currently support MaxMind City databases in the MaxMind DB format, as the GeoIP2 City Database or GeoLite2 City Database that MaxMind provides.

The next step is to store the geolocation database in all servers running Graylog. As an example, if you were using the Graylog OVA, you could save the database in the /var/opt/graylog/data folder, along with other data used by Graylog. Make sure you grant the right permissions so the user running Graylog can read the file. Continue reading “Add Geolocation to Graylog 2” »

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