Happy Holidays and 2nd Blog-Anniversary

Well, its that time of year again where snow is upon us and houses are filled with families celebrating the Holidays. 2 years ago I started this blog while working as a systems admin at a small company finding my path in the IT world and posting lessons I’ve learned along the way. Over the past 2 years my career has grown from a virtualization and Windows admin to working as an Operations Engineer for a hosting company primarily working on Linux systems and various hypervisors. I’ve now found myself in a DevOps role as a cloud engineer working on high availability cloud architecture for household name entertainment companies. Blogging has been a passion of mine throughout my career as i have relied on the blogs of others as well as documentation to find my way out of difficult issues. For things I’ve run into that weren’t terribly intuitive I felt it my responsibility to contribute back to the community in hopes that I can save someone else the same headache I went through to fix an issue. As I come to the 2nd anniversary of the blog I just want to say thank you to all who have come here and read posts and wish all of you happy holidays and happy new year. Also if you’re an IT professional I highly encourage you to blog and contribute back to the community, even if you feel like you don’t have much to contribute, I guarantee you do.

Fedora 24 Wireless Working on Dell Latitude E-Series

As many who personally know me, my favorite laptop is my trusty old Dell Latitude E-6320, it’s a few years old now but still rocks an i5, SSD, and 8gb RAM and gets the job done nicely. I use this at home with a docking station which works great with wired network connections, however I’ve found wireless to be an ongoing battle with this laptop on Fedora 24. So I turned my fix into a script and posted it on my Github!


Hope this helps other poor saps who love to run Fedora on Dell Enterprise grade laptops!

CoreOS on Citrix XenServer 7 Setup Guide

This article applies to Citrix XenServer 7, for version 6.5 please ensure you are using the correct supplemental pack

Installing the Supplemental Pack

SSH into your XenServer host and run the following to download the ISO

wget http://downloadns.citrix.com.edgesuite.net/11621/XenServer-7.0.0-xscontainer.iso

Next run the following command to install it

xe-install-supplemental-pack XenServer-7.0.0-xscontainer.iso

Once this is installed you can rm the iso from dom0 to conserve space.


Installing CoreOS Guest

Use the new VM wizard selecting the CoreOS ISO when prompted for the install media and when you get to the final portion where it asks you to complete the cloud-config template ensure you enter a hostname in the top line, and uncomment the line for ssh-rsa and add a key, or you will not be able to SSH into the VM. Once the VM is booted you will see the ip address in the console, attempt to ssh to this using the username core@ipaddress to ensure your SSH key is working.

If your SSH key does not work at this point power off the VM and fix it before proceeding to the next step as it is the point of no return.


Installing CoreOS to Disk

SSH to your CoreOS VM. The command below will complete the installation of CoreOS to disk on your VM:

sudo coreos-install -d /dev/xvda -o xen -C stable

Once this completes you will need to execute the following:

sudo reboot

Once the reboot has completed you will need to set a password for the core user

sudo passwd core

Once you provide a password and confirm the password you can proceed to the next step which allows monitoring of containers by dom0


Enable Container Monitoring

To enable container monitoring you will first need the UUID of your CoreOS VM. Execute the following command via SSH on your XenServer host:

xe vm-list power-state=running

Copy the UUID over the VM to your clipboard then run the following command:

xscontainer-prepare-vm -v <UUID of VM> -u core

You bill be asked if you’d like to push a pool specific SSH key to the VM for monitoring, choose yes and enter the password you set for the user core in the previous step.


Verify Functionality

The next step will be to pull a docker repo of your choice, for my example I will use centos:latest

docker pull centos:latest

Next we will start a docker instance:

docker run -i -t -d centos:latest /bin/bash

At this point we should be to make sure our container is successfully running from the CLI:

docker ps

Now in the Citrix XenCenter console we should see a plus sign next to our CoreOS VM. Once this is expanded you should be able to see the docker container you started by name.