Posted on:
November 23, 2015
Nov 16
Igniting Talks: a Learning Experience
I’ve been a bit quiet of late; been busy, to say the least. Work has been crazy (and will be for the foreseeable future), but among other things, I have been working on an Ignite style talk for DevOps Days Ohio. Why so busy? Well…. in part because it’s a more difficult type of speech than “normal” — while there are but 20 slides, they advance automatically after 15 seconds.
More, though, due to the brilliant idea I had for a theme…. which goes something like this:
- Talk is on the Three ‘R’s of DevOps
- Three ‘R’s — like School’s three ‘R’s
- School….
- Chalkboard
- Let’s do slides as though they were chalkboard drawings.
Yes… hand lettered, hand drawn, on black paper. Mind you, I’d not done much hand lettering in a while. And black paper is a new experience. In some ways it’s less forgiving than white, I think. But I forged ahead, nevertheless…
Nov 07
DevOps Days Ohio
3 R’s of DevOps
DevOps Days Ohio
18-19 November 2015
I’m speaking at DevOps Days Ohio on the “3 R’s of DevOps”
Oct 09
Mounting Partitions from Image Files on Linux
I’ve been working with disk images from the excellent crew from Hypriot and there are times when I wish to mount the filesystems within to inspect and or make alterations to them. Since there are multiple filesystems, it’s not like mounting an ISO image — there’s more work which needs to be done.
Being a “lazy”(pronounced SMART) sysadmin type, I did some research and discovered a wonderful tool called kpartx — it will read the partition table of the image and create device mappings for the partitions.
Typically it is called as follows:
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$ sudo kpartx -av IMAGE_FILE add map loop2p1 (252:4): 0 131072 linear /dev/loop2 2048 add map loop2p2 (252:5): 0 2296567 linear /dev/loop2 133120 $ mount /dev/mapper/loop2p1 /mnt |
Note: despite the line saying /dev/loop2, the partition’s synthetic device is actually at /dev/mapper/loop2p1
Oct 08
Solving File Filtering Problems with this One Weird Trick
I was asked an interesting question — how to create a regular expression which would allow a user to specify an arbitrary case insensitive series of strings, all of which must be on a line, as well as a series of strings which must not be on a line in order to filter logs. In either case, the strings could be found in any order anywhere on the line. He was using Perl to process the arguments and run the filter. Generally I would have piped together several greps, but it sounded like an interesting challenge….
Oct 07
Hypriot Does it Again
Many thanks and kudos to the most excellent people at Hypriot on their latest release!
Hypriot has made Docker on the Pi easy — prior to their distribution it took a lot of blood, sweat, and tears to compile and get Docker working on the Pi. (Trust me!!! Been there, done that, have the t-shirt). Not only do they have Docker, but Swarm, Machine, and Compose as well. While I was able to get some of them working as a “Look, Ma, no hands!” type of test, I really have to hand it to them — they have gone the extra mile, going above and beyond to productionize the environment and provide a easy-to-use distribution and SD card.
Now for the Goodies:
- Debian Jessie
- Their own apt package treasure chest is built in. There’s some shiny gems hidden in it, too!
- Linux 4.1.8
- Docker 1.8.2
- Docker Compose 1.4.2
- Docker Machine 0.4.1
- Docker Swarm 0.4.0 — preinstalled as a docker image, but it’s also available via
apt - Network Hotplugging Baked Right In
- Wifi
- Support for Avahi and OpenvSwitch
With each release, Hypriot is more and more polished — it is truly a gem!
Flash scripts are available for Linux and OSX for writing the SD card image; I’ve submitted a patch for some more functionality on the Linux end; I expect it will get included in the next day or so, but if you can’t wait, you can grab it from my fork.
I’ve had the opportunity to play a bit with it and really like it. Plug it in and it just works. I’ll have some more about it over the next few days, but if you’re wanting to explore Docker on the Raspberry Pi, this is the best way to go.
Look for more exciting things to come from the Hypriot Crew!
Oct 06
Just because I Koan
If you have some ice cream,
I will give it to you.
If you have no ice cream,
I will take it away from you.
It is an ice cream koan.
Ruby Metakoans
In software, koans are a form of kata, or practice. There are a number of these; one of the first I’d encountered is the Ruby Quiz – metakoans.rb (#67). I’d first solved it eight or nine years ago, but decided to do it again to brush up on my skills. In the intervening years, there have been a few changes to Ruby, but only one real change needed to be made:
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$ diff metakoans_orig.rb metakoans.rb 231c231 < require knowledge --- > require_relative knowledge |
First time it took me a few hours to write. This time, it took less than an hour to get it working… amazing the difference time makes. Also, as I (dimly) recall my previous version was not as maintainable — I used a lot of instance_eval rather than define_method as I did this time. But I don’t want to give any more away in case y’all might want to give it a try.
I’m putting my solution here (with a patched metakoans.rb): download.
Neo Ruby Koans
A more general ruby language practice is Neo’s Ruby Koans. It’s inspired, in part, by the metakoans. This one is a bit longer — there are approximately 280 separate tests/exercises. That one is geared more toward people who are first learning, but there were some things which I don’t remember having come across before. A good exercise, all in all.
I’m going to look for some more koans…..
“Rubin, biotyt, Ihosy, Madagaskar“. Licensed under Wikimedia Commons.
Oct 05
Speaking at DevOps Days Ohio
DevOps Days Ohio is taking place in 18-19 November 2015. I’m going to present an Ignite format talk on the Three ‘R’s of Devops.
There’s going to a lot of great people that are going to be there. I am really looking forward to it!
Oct 03
Ally Skills Workshop
Today at Ohio Linux Fest I attended the Ada Initiative’s Ally Skills Workshop.
The Ally Skills Workshop teaches men simple, everyday ways to support women in their workplaces and communities. Participants learn techniques that work at the office, at conferences, and online. The skills we teach are relevant everywhere, including skills particularly relevant to open technology and culture communities. At the end of the workshop, participants will feel more confident in speaking up to support women, be more aware of the challenges facing women in their workplaces and communities, and have closer relationships with the other participants.
The workshop was really thought provoking. I’m still processing a lot from it, but already I can see ways that I may not have been as supportive as I might once have and ways in that I can be more so.
I’d highly recommend it to everyone should they get the chance to attend.
