Mount a Windows NTFS Disk in Linux

Almost all of the Windows OS disks use NTFS as a filesystem. It has been there since long time. However it is proprietary to Microsoft and is therefore not open sourced. By default, you’ll not be able to mount NTFS disk in the linux distributions like CentOS, RHEL etc. However it is possible to install a driver that allows us to do this so that we can read and write data to an NTFS disk.

In this blog post, we’ll see how to do the same. For the demo purpose we’ll be mounting a NTFS disk, inside CentOS.
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Install Jenkins in offline mode on CentOS / RHEL

There are times when you would need to do an offline installation of the Jenkins. This may be to meet certain requirements of the workplace that you are operating in. I came across this issue some time back and internet is woefully out of articles for proper steps on this one. In this blog post, we’ll learn how to do an offline installation of Jenkins.

Install OpenJDK Java

First, we need to check what version of java is installed on the machine using:
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Use OpenSSL to work with SSL Certificates, CSR and Private Keys

OpenSSL is a robust, commercial-grade, and full-featured toolkit on the Linux that can be used for a large variety of tasks related to Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols. It is also a general purpose cryptography library. It is licensed under an Apache-style license, which basically means that you are free to get and use it for commercial and non-commercial purposes subject to some simple license conditions.

It is already installed out of the box on the most linux distributions or available in the trusted package repositories. OpenSSL has been kind of standard in the open source domain to work with SSL and TLS protocols. If for some reason, it is not already installed, you can install it by using your distribution specific commands.Read More »

Install dotnet core SDK and runtime on Ubuntu OS

.NET Core is the cross platform and open-source framework based on .NET framework.  It is maintained by both Microsoft and the community at https://github.com/dotnet/core on Github. In this blog post, we’ll learn to install dotnet core on the  Ubuntu. For the post’s purpose we’ll use Ubuntu 16.04 since that is latest LTS release from Ubuntu which has the support from almost all software vendors.

Register Microsoft key and feed

Before installing .NET, you’ll need to register the Microsoft key, register the product repository, and install required dependencies by running the following commands:Read More »

Install Azure CLI 2.0 on Ubuntu

Azure CLI or Azure command line interface is a cross platform command line tool offered by Microsoft to work with Microsoft Azure and manage azure resources. One can use it in the browser (in the azure cloud shell) or it can also be installed or major Operating Systems of one’s choice. Azure CLI 2.0 is optimized for managing and administering Azure resources from the command line, and for building automation scripts that work against the Azure Resource Manager.

Do note that azure is the prefix for old CLI – Azure CLI (i.e. version 1.0) , and that az is the prefix for the new CLI – Azure CLI 2.0. Read More »

Stop a script from running if it’s not root

This is a very short post and relies on the knowledge that UID of root user is always 0 regardless of the name of the root account. If the effective UID returned by id -u is not zero, the user is not executing the script with root privileges. Below simple code can be used to check against if script is running as root or not:

#!/bin/sh

if [ "$(id -u)" -ne 0 ]; then
        echo 'This script must be run by root user' > &2
        exit 1
fi

 

Create a kubernetes cluster on CentOS

What is Kubernetes?

Kubernetes, or k8s or “kube”, if you’re into brevity, is an open source platform that automates Linux container operations. It eliminates many of the manual processes involved in deploying and scaling containerized applications. In other words, you can cluster together groups of hosts running Linux containers, and Kubernetes helps you easily and efficiently manage those clusters. These clusters can span hosts across public, private, or hybrid clouds.

Kubernetes was originally developed and designed by engineers at Google. Google was one of the early contributors to Linux container technology and has talked publicly about how everything at Google runs in containers. (This is the technology behind Google’s cloud services.)
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Become root user on Linux servers in Azure

root is the user name or account that by default has access to all commands and files on a Linux or other Unix-like operating system. It is also referred to as the root account, root user and the superuser. The root account is the most privileged on the system and has absolute power over it (i.e., complete access to all files and commands). Among root’s powers are the ability to modify the system in any way desired and to grant and revoke access permissions (i.e., the ability to read, modify and execute specific files and directories) for other users, including any of those that are by default reserved for root.

It is therefore, many times, you need to login as root in order to perform certain administrative actions. Read More »