Minicloud: the Free OpenPower cloud

I recently got access to the Minicloud, a Free OpenPower Cloud hosted by Unicamp, one of the most prominent universities in Brazil. This cloud is a good way to ensure that your application provides good support for the Power architecture.

Having access to this cloud, I can help ensure that some of the projects I am interested about can be ran and supported on this architecture. Additionally, it offers me a Power environment to test the messaging-related packages I maintain on Fedora and CentOS – entirely on my free time.

To start with this cloud, I decided to go big and deploy Maestro there. Having only 4Gb, it means that I need to adjust very well the resources of my VMs so that I can maximize the usability of the cloud environment. I will write some posts about this.

The other project that I am interested in playing with in the Minicloud is Paho C, the MQTT client from Eclipse Foundation. As the Fedora maintainer for the package, having access to this environment means that I have a personal environment where I can ensure the quality of the packages.

How to find the IP address of Linux guests

There’s a lot of examples in the internet showing how you can obtain the IP address of a libvirt guest virtual machine. Most of the examples show how to do that when the network is using NAT forwarding (aka “Virtual Networks”).

However, how to do that if your setup is using Bridged Networking and your guests receive an IP address from an external DHCP server?

One idea is to install the read the DHCP leases file straight from the guest FS. You can do that by using the libguestfs-tools to cat the file within the image. For RHEL 6 (and CentOS 6 and similar distributions) the process is similar to this:

For RHEL 7 (as well as CentOS 7 and similar) the process is slightly different due to the way NetworkManager stores the leases file:

In this Gist there’s a modified script I used to update the IP address of all guests in one shot.

EOY 2016 links

Some links about interesting things I’ve read or watched by the end of 2016. Further comments are provided on each item of the list.

 

Linux fanzines

Although man pages are essential for anyone doing serious work on Linux and other Unix-like operating systems, it’s hard to advocate for them as being user friendly and easy to read. Therefore, evangelists invent all sorts of things to spread knowledge about their favorite tools and technologies: tutorials, e-books, videos, etc. There’s even a coloring book that teaches how SELinux works. Now we have one more addition to the mix: fanzines. If you like them, this website has some very interesting and funny zines about programming, debugging and Linux in general.

 

Macbook touchpad configuration tip for Fedora Linux

Some time ago I wrote a few tips about Running Fedora 22 on a Late 2013 Macbook Pro (Retina). Fedora is now on its version 24 and remains the best Linux distribution out there and the tips are still valid.

However, there’s one new tip. Instead of dealing with the Synaptics/Synclient stuff by yourself, you may want to try using the configuration from my Copr repository instead:

And with that you should have a touchpad behavior that is similar to the one on OS X.