DNF is a next generation package manager for RPM-based Linux distributions, commonly used in newest Fedora releases. DNF is a Yum succesor, which provides Yum backward compatibility, but one of aspects, which make DNF a powerful package manager is the ability to manage transaction history.
Using DNF, we can easily undo or redo RPM package upgrade, installation and removal. This gives us the opportunity to rollback the system, if we feel, that our recent RPM package operations disordered the system.
Below we presents, how to work with DNF transaction history on Fedora 24.
Continue reading “Fedora DNF rollback RPM package update, removal, installation”
WebDAV (Web Distributed Authoring and Versioning) is an extension of the Hypertext Transfer Protocol (HTTP) that allows clients to perform remote Web content authoring operations. The WebDAV protocol provides a framework for users to create, change, copy, move, lock and version the files on a server, typically a web server or web share. This type of protocol is used by some hosting providers (like my favorite HostUpon) in cPanel software, to provide quick and easy access to the files stored in hosting account disk space.
In this tutorial we are mounting remote WebDAV resource in Fedora release 24 via davfs2 file system driver.
Continue reading “Mount WebDAV remote storage in Fedora Linux using davfs2 driver”
Jenkins is a popular and open source automation server written in Java, which helps automate the non-human part of the whole software development process. Jenkins supports BASH shell scripts, can be integrated with version control systems and it’s builds can be scheduled via a cron-like mechanism.
In this tutorial we are installing Jenkins stable version from RPM package via Jenkins dedicated repository using DNF package manager.
Continue reading “Install Jenkins on Fedora 23 from RPM via DNF package manager”
OpenStack comes out of the box with it’s dashboard called Horizon. Horizon provides GUI, which let us manage our OpenStack environment in pretty easy and inuitive way. However basic tasks, like tenant creation or instance commissioning, can be time consuming when performed in Horizon. Using command line interface with previously prepared command templates can be more efficient and faster.
In this tutorial we present how to create Project Tenant in OpenStack Newton using command line intrerface and launch Cirros based Instances inside the Tenant.
Some time ago OpenStack Community introduced new tool called OpenStackClient (OSC) with it’s openstack command utility to unify OpenStack management, which encompasses the following components: Compute, Identity, Image, Object Storage and Block Storage APIs. So far keystone command utility was withdrawn from OpenStack as deprecated and replaced by mentioned openstack command utility. In this tutorial for Newton release we are going to use openstack commands where possible to become familiar with OpenStackClient CLI.
Continue reading “Create tenant in OpenStack Newton using command line interface”
In OpenStack all-in-one configuration all OpenStack nodes (controller node, compute node, network node) are installed on a single machine. All in one configuration can be quickly deployed for testing purposes and is often recommended for developers to test their applications on top of OpenStack environment.
In this tutorial we install OpenStack Newton release from RDO repository including Heat Orchestration service on single node (all-in-one installation) based on CentOS 7 / RHEL 7 using packstack installer script.
Continue reading “Install OpenStack Newton All In One with Heat Service on CentOS 7”
Ansible is a simple open-source automation tool that can automate cloud deployment, application deployment or Linux OS maintenance. Comparing Ansible to other automation tools (i.e. Puppet), it’s the simplest tool, because it’s agentless. Ansible once installed on a control node, connects to a managed node via SSH, which doesn’t require any client applications installed on that node.
Installation of Ansible on Fedora based control node is pretty simple and straightforward, since it can be installed from RPM packages. In this tutorial we are installing Ansible on Fedora 23 via dnf package manager.
Continue reading “Install Ansible on Fedora via DNF from RPM packages”
GRUB2 Linux Boot Loader provides few customization options, that can transform it into an attention drawing eye candy. It’s main feature is the possibility to customize the splash screen being displayed with GRUB 2 menu entries upon system boot. This feature can be used not only in GRUB2 installed on hard disk for already installed operating systems, but also in GRUB2 Boot Loader placed on ISO image when booting from ISO/CD/DVD. This is pretty useful as well, when we want to create customized ISO image with the company logo based on some Linux Distro, which provides a company product.
In this tutorial we present how to create:
- GRUB2 custom splash screen on RHEL 7 / CentOS 7 ISO image for UEFI Boot
- GRUB2 custom splash screen on RHEL 7 / CentOS 7 ISO image for Legacy BIOS Boot
Continue reading “GRUB 2 Custom Splash Screen on RHEL 7 UEFI and Legacy ISO Image”
Oracle VM VirtualBox is a flexible open-source hypervisor for x86 computers from Oracle Corporation initially developed by Innotek GmbH. It runs on many platforms including: Linux, Windows, Solaris, providing great virtualization environment to run multiple VMs at a time.
In this tutorial we present how to install VirtualBox 5.1 on Fedora 23 from RPMs in few simple steps.
Continue reading “How to Install VirtualBox 5.1 on Fedora 23 from RPMs”
Linux includes by default a bunch of useful filesystem tools that can be used to locate filesystems or partitions with specified tags or display the whole list of block devices along with their labels, universally unique identifiers (UUIDs) or default mount points.
Below we present common tools to locate filesystem, block device or list all block devices in Linux.
Continue reading “How to find Linux filesystem by Label or UUID using findfs, lsblk, blkid”
OpenStack is a free and open source cloud computing platform developed as a joint project of Rackspace Hosting and NASA, consisting of many well know technologies like: Linux KVM, LVM, iSCSI, MariaDB (MySQL), RabbitMQ or Python Django.
In our previous articles we presented OpenStack installations based on VLAN internal networking.
In this article we will install OpenStack Newton release from RDO repository on three CentOS 7 based nodes (Controller, Network, Compute), but this time, unlike our previous articles, we will use VXLAN based internal networking for communication between Nova Instances.
Continue reading “OpenStack Newton VXLAN based installation on 3 CentOS 7 nodes”