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Setup an NFS client provisioner in Kubernetes

Setup an NFS client provisioner in Kubernetes One of the most common needs when deploying Kubernetes is the ability to use shared storage. While there are several options available, one of the most commons and easier to setup is to use an NFS server.
This post will explain how to setup a dynamic NFS client provisioner on Kubernetes, relying on an existing NFS server on your systems.
Step 1. Setup an NFS server (sample for CentOS) First thing you will need, of course, is to have an NFS server. This can be easily achieved with some easy steps:

Install nfs package: yum install -y nfs-utils Enable and start nfs service and rpcbind:
systemctl enable rpcbind
systemctl enable nfs-server
systemctl start rpcbind
systemctl start nfs-server
Create the directory that will be shared by NFS, and change the permissions:
mkdir /var/nfsshare
chmod -R 755 /var/nfsshare
chown nfsnobody:nfsnobody /var/nfsshare
 Share the NFS directory over the network, creating the /etc/exports file:
vi /etc/exports
/var/nfsshare …

Create and restore external backups of virtual machines with libvirt

A common need for deployments in production, is to have the possibility of taking backups of your working virtual machines, and export them to some external storage.
Although libvirt offers the possibility of taking snapshots and restore them, those snapshots are intended to be managed locally, and are lost when you destroy your virtual machines.
There may be the need to just trash all your environment, and re-create the virtual machines from an external backup, so this article offers a procedure to achieve it.
First step, create an external snapshot So the first step will be taking an snapshot from your running vm. The best way to take an isolated backup is using blockcopy virsh command. So, how to proceed?

1. First you need to extract all the disks that your vm has. This can be achieved with domblklist command:
DISK_NAME=$(virsh domblklist {{domain}} --details | grep 'disk' | awk '{print $3}')

This will extract the name of the device that the vm is using (vda, hda, et…

Automating local mirrors creation in RHEL

Sometimes there is a need to consume RHEL mirrors locally, not using the Red Hat content delivery network. It may be needed to speed up some deployment, or due to network constraints.

I create an ansible playbook, rhel-local-mirrors (https://github.com/redhat-nfvpe/rhel-local-mirrors), that can help with that.
What does rhel-local-mirrors do? It is basically a tool that connects to the Red Hat CDN, and syncs the repositories locally, allowing to populate the desired mirrors, that can be accessed by other systems via HTTP.

The playbook is performing several tasks, that can be run together or independently:
register a system on the Red Hat Networkprepare the system to host mirrorscreate the specified mirrorsschedule automatic updates of the mirrors How to use it?It is an Ansible playbook, so start by installing it, in any prefered format. Then continue by cloning the playbook:
git clone https://github.com/redhat-nfvpe/rhel-local-mirrors.gitThis playbook expects a group of servers called