суббота, 16 августа 2014 г.

Semi-irregular Intresting Github Repos Ops Digest #10 (August 15)

Hi All,

New name for that digest come into my mind - Semi-irregular! It sounds good for me, let's stick with that.
I want to make some celebration with Issue #10, but first I found out that no really cool projects to show for a week - maybe because of summer/vacation time, I don't know. So, I was waiting for one more week, and now -

Semi-irregular Intresting Github repos (for) Ops Digest, issue 10:

First, fresh docker projects:

1. docker-cheat-sheet
Docker Cheat Sheet

Good cheat sheet for Docker, must read.

2. flocker
Easily manage Docker containers and their data https://clusterhq.com

Open-source Docker orcestration service. Also, not much to say, please try tutorial.

3. flynn
A next generation open source platform as a service (PaaS) https://flynn.io

Ah, that's more complicated thing, but looks very promising - latyered open-sourced PaaS platform, check it out.

4. github-trending
Tracking the most popular Github repos, updated daily

Self explanatory, tracking the most popular Github repos and updating list of top objective-c, javasript and go repos in markdown output daily. You can pick other languages and run own tracker if you want.

5. cloud-ssh
Cloud enhanced SSH client replacement with host auto-completion

Cloud enhanced SSH client replacement with host auto-completion, espicially nice for AWS hosts.

6. cpubars
Lightweight terminal-based multicore CPU usage monitor

cpubars is a simple terminal-based tool for monitoring CPU load in real-time, especially tailored to monitoring large multicores over SSH.

7. Password-Repo

Quite good collection of password lists, which help to your services be more secure, I mean if you will deny using that obvious passwords for users.

8. mooltipass
Github repository dedicated to the mooltipass project

Very nice project, indeed, like it very much! Aruino-based hardware password storage, powered by smartcard - wow! Fully open-sourced. Prototype is looking like that:

Ceators selling it for 80$, but real paranoid needs to built this by own, of course.
More and more sysadmin tools starts to be written in Go language. This is collection of Go stuff for ops engineers, check it out
And useful port of psutil library for Go:
10. gopsutil
psutil for golanghttps://github.com/shirou/gopsutil

Also some vim plugins was detected by by Github radar this week:

11. vim-plug
Minimalist Vim Plugin Manager https://github.com/junegunn/vim-plug

New Vim plugin manager, like it:

12. vim-grammarous
A powerful grammar checker for Vim using LanguageTool.

"vim-grammarous is a powerful grammar checker for Vim. Simply do :GrammarousCheck to see the powerful checking"

13. vim-go
Go development plugin for Vim https://github.com/fatih/vim-go

"Full featured Go (golang) support for Vim. It comes with pre-defined sensible settings (like auto gofmt on save), has autocomplete, snippet support, improved syntax highlighting, go toolchain commands, etc... It's highly customizable and has settings for disabling/enabling features easily."Nuff said.

Fun section:
14. carp
"interesting" VM in C. Let's see how this goes. 
Sample realization ov virtual machine in C. Check if you want to how to find how VM works.

15. sunfish
Sunfish: a Python Chess Engine in 111 lines of code

"Sunfish is a simple, but strong chess engine, written in Python, mostly for teaching purposes. Without tables and its simple interface, it takes up just 111 lines of code!
The clarity of the Sunfish code provides a great platform for experimenting, be it with evaluation functions, search extensions or anything. Fork it today and see what you can do!"

16. anagramatron
twitter anagram hunter http://anagramatron.tumblr.com/

"Anagramatron hunts for pairs of tweets that use the exact same set of letters.
This script connects to the twitter stream. When it receives a new tweet it runs it through some filters, ignoring tweets that contain things like links or @mentions, or that contain less then a minimum number of characters."
You can check results of it on http://anagramatron.tumblr.com/

Small disclaimer: I'm just big fan of Github and since we have so many sources of information around I pick Github as source of information for my digest of interesting open-source projects. And because I'm Ops/Sysadmin person - I choose projects which somewhat ops-related, but not necessary. I'm not GitHub employee and this digest is not connected with GitHub in any way.

четверг, 7 августа 2014 г.

Google hiring task (first 10-digit prime in e) in bash one-liner

Hi All,
I was on a bit of short vacation, and according to my vacation rules I'm trying to not to think about my work-related stuff, or any computer-related stuff overall. I was not successfull completely with that target thanks to my smartphone :) but tried to. But during my train voyage I was quite bored, so, I was thinking about task which my friend and fellow colleague master Victor mentioned - it was famous foto of billboard which was used by Google for hiring purposes back in 2004 -

And master Victor said - "assuming you know about the e constant, solve in a Bash one-liner to get a job @Google :)" - and I was thinking about that during my trip. And I was succeded - with some remarks, of course.
Disclaimer: IMHO solving this thask in Bash is NOT GOOD, because it violates first principle of engeneering - "choosing the right tool for the job" - and bash definitely is not good for that task.
So, first I tried to find is that task could be solved in "pure bash" and I found that it is not. You can check that thorough investigation to find out that calculating e with required precision is not posible in bash because of integer overflow.
So, let's "cheat" - i.e. use some tools with bash. Which tools are suitable and not count as cheating? I think bc is absolutely required for math operations, also other unix tools, like sed and coreutils are also OK.
Let's divide task into pieces:

1. Generate e with enough precision (1000 digits)?
I found that you can easily do it with bc:
root@ubuntu:~# echo "scale=100;e(1)" | bc -l 2.718281828459045235360287471352662497757247093699959574966967627724\ 0766303535475945713821785251664274

2. We need to go through digits of e and take each 10 digits to check, then move to 1 digit forward and repeat, and so forth. We can do it using temporary file and "cut -cX..Y" syntax, but I found that using bash variable and bash string manipulation (${string:X:10}) is much convenient.

3. We need to check is current number prime or not. We can do it on "pure bash" too, but I found that we can use infamous factor tool from coreutils to do that task:

root@ubuntu:~# factor 100 100: 2 2 5 5
root@ubuntu:~# factor 177 177: 3 59
root@ubuntu:~# factor 179 179: 179

As you can see, factor tool make number factorization for any not really big integer number - it's quite enough for our purposes.
So, let's glue everything together:

And output is:
Answer is 7427466391. And we can also fold it to one-liner of course:

Misson accomplished. :)

воскресенье, 3 августа 2014 г.

Random Ops Github Digest #9 (August 3rd 2014)

Hello, my fellow readers!
I decided not ot wait until tomorrow and make new digest right now - still not sure if this digest will be weekly or more random and sporadic. :)

So, let's start, again, my favourite Github projects (sometimes Ops-like) in no particular order.

1. cheat
cheat allows you to create and view interactive cheatsheets on the command-line.

Like man command, but you'll get small cheatsheet just with commands instead big man page. Still not sure is it good thing or not....

2. awesome-django
A curated list of awesome Django apps and projects.

Another Awesome list, but for Django developers. Can be useful for Django Ops too.

For you, fellow Puppeteers:

3. r10k
Smarter Puppet deployment, powered by killer robots

Relatively new tool for Puppet installations, useful if you using librarian and dynamic environments.

4. hiera-consul
Hiera backend plugin for Consul

If you have working Consul cluster you can get/set vualues there directly from Hiera.

Going to DevOps stuff:

5. terraform
Terraform is a tool for building, changing, and combining infrastructure safely and efficiently. http://www.terraform.io

"Infrastructure-as-code" tool - describe your infrastructure, deploy and control it on different providers. It's not Puppet replacement though - http://www.terraform.io/intro/vs/chef-puppet.html - it's just more high level tool.

6. infratester
Infrastructure Behavior Testing Framework http://infrataster.net

Another "Infrastructure-as-code" tool - it tests infrastructure's behaviour from outside of servers:

7. devstep
Development environment builder powered by Docker and buildpacks

A dead simple, no frills development environment builder that is based around a simple goal:
"I want to git clone and run a single command to hack on any software project."
For more information please check http://fgrehm.viewdocs.io/devstep

8. libcloud-vagrant
Apache Libcloud compute provider for local Vagrant boxes

"libcloud-vagrant is a compute provider for Apache Libcloud which uses Vagrant to create VirtualBox nodes. With libcloud-vagrant installed, you could prototype a small cluster on your laptop, for instance, and then deploy it later on to Amazon, Rackspace, or any of the other clouds supported by Libcloud."

Rest of things:

9. seL4
seL4 microkernel

Freshly opensourced L4-based microkernel, which has formal verification proof. Not really practical thing, but interesting - check its FAQ if curious.

10. snapzend
zfs send/receive backup system http://www.znapzend.org

Cool new backup system specifically for ZFS!

11. pghero
Database insights made easy
Personally I didn't work with more-less loaded instance of PostgreSQL for quite long time. But if you do - please check it out - it's nice web dashboard for pg:

Today's fun section is quite big:

12. cool-old-term
A good looking terminal emulator which mimics the old cathode display

Looks cool - but not sure is it OK for work:

13. ld-preload-sounds
Generates raw WAV output by hooking malloc() and read().

You can now hear how your compilation sounds like!

14. conway
A real-time, persistent, multiplayer version of Conway's Game of Life

You can roll out your own server and play with friends or play with strangers right now on http://lifecompetes.com

Small disclaimer: I'm just big fan of Github and since we have so many sources of information around I pick Github as source of information for my digest of interesting open-source projects. And because I'm Ops/Sysadmin person - I choose projects which somewhat ops-related, but not necessary. I'm not GitHub employee and this digest is not connected with GitHub in any way.