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Showing posts from June, 2014

automirror - Automate Linux Screen Mirroring

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I do a lot of pair working and many times I connect a large TV or projector to my laptop for others to see what I am doing.

Unfortunately the display resolution of my laptop never matches that of the other display, and Linux tends to choose 1024x768 as the highest compatible resolution. This is of course totally useless for doing any real work.

My preferred solution for this problem is to use X scaling to bridge the resolution gap between the different screens.

Since none of the regular display configuration tools support scaling, I ended up typing this line very often:

xrandr --output LVDS1 --mode 1600x900 --output HDMI3 --mode 1920x1080 --scale-from 1600x900
Eventually I got fed up and decided to automate the process, the result is automirror, a little Bash script that automatically configures all attached displays in a mirror configuration. automirror is available on https://github.com/schlomo/automirror.
Typical Use Cases Connecting a Full HD 1920x1080 display via HDMI to my 1600x…

Granting root access in a DevOps world

At the 2014-06 Berlin DevOps Meetup this week we had an interesting fish bowl discussion about

What is the risk of giving DEVs root access in production?

Since I suggested the topic I was asked to give a short introduction into the topic:


The discussion that followed was suprising in several aspects:
A major concern is safeguarding the production data, but nobody had a really good solution for that. Many people have more problems with Developers seeing live customer data than with Develops changing something in production."Nobody should have root" was proposed by a security specialist, but he had no practical working example for this approach.The question is tightly coupled to the degree of automation. The more automation you have the less need for anybody (Dev or Ops) to use their root privileges.Not everybody having root access knows what to do with it, Developers are sometimes afraid of using their power if granted root.This is mostly a question for larger companies and cla…

My SMART TV - Linux For The Win

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I love my "smart" TV - it got Linux inside which is the base for a whole range of nice hacks.
TV Router The most important one is that the TV is actually a wireless router that provides Internet via Ethernet to my TV rack. Usually the Ethernet connection is used by the Playstation or a Raspberry Pi.
The original reason for this hack was simple: The Playstation 3 has a really really bad Wifi reception which made watching Netflix nearly impossible and the unavoidable PS3 updates painfully long. The USB Wifi adapter connected to the TV has a much better reception, sharing it with the PS3 solved all the performance problems.
Samsung Linux TV And here comes the good part. The TV (Samsung LE32C650) runs Linux inside and there is an Open Source project (SamyGO) that "opens up" the TV firmware and extends this Linux with useful tools.

In my case I only had to enable IP forwarding, configure a static IP on the Ethernet interface (eth0) and start a DHCP server on it. The Sam…