Speeding up office work with Ruby and IRB

I was just paying taxes ūüėÖ. One of the steps involved was copying and pasting a few long reference numbers from a PDF into my banking app. The thing is, when copied, the reference number would contain extra spaces, after each character, making it invalid where I needed to paste it.

Now there are myriad of different solutions for this I’m sure, but as a programmer, let’s take a look at how to speedily create a makeshift tool in Ruby to do this.

space_eater = ->(text) { text.gsub(' ', '') }

We launched into the interactive shell, and defined a lambda we can call on strings we want to sanitize. Like so:

space_eater.call('2 3 9 2 9 9 A 8 2 8 0 0 0 1')
=> "239299A8280001"

And we’re done. ‚̧ԳŹ Ruby.

Dockerized Percona MySQL Server with automated replication, tools & tests

Docker & Percona Server I developed this container to solve specific needs and alleviate pain points present when dealing with deployment and administration of MySQL on servers that I manage.

I decided to look into Docker during a migration from MySQL 5.5 to 5.6 on one of the production servers. The server hosts multiple applications and services and is running in a hot spare configuration (another server mirrors this server, acts as the MySQL slave, etc.). Thus I wanted a migration strategy where I can have the 5.6 installation ready and running on the server, so that I can test it with production data and when ready just turn the switch to replace the old 5.5. Docker turned out to be the cleanest solution.

Since the MySQL server is such a critical part of the infrastructure I decided to develop the container utilizing test driven development. This allowed me to quickly add new features, like performance optimization and replication over a ssh tunnel (to support servers in different public clouds). Having this functionality in a standalone, tested and isolated unit is amazing. Before, all this complexity would be managed by Chef provisioning, which is much harder to test and experiment with on the production server. Having this functionality contained in a Docker container allows me to just use Chef for orchestration and deployment of the containers themselves, witch requires much simpler logic, compared to provisioning a full MySQL server install, configuration, replication and upgrading.

  • Code is available at Github.

This project is released under the MIT license.


serversSoon after I started working with Rails, I wanted to start using my own server environment, instead of a managed hosting. I wanted to be able to use any kind of libraries, their versions and any other tools my projects required on my server, set up the way I need it. Thus I got my first VPS.

From one small VPS server, over a period of a few years, I find¬†myself managing 6+ dedicated servers to serve¬†the needs of the applications I’ve developed and maintain.

At the beginning I managed my first server manually: ssh into the machine, install packages, edit the configs… This soon became tedious and I was aware that there are tools designed to do this better. I picked up Chef¬†and never looked back. Nowadays all my servers are managed by cookbooks, deployed by chef-solo in conjunction with my own knife-like toolset based on Mina.

Here’s a short list of some of the more interesting things that I’ve learned and have experience with in conjunction with DevOps:

  • MySQL configuration, backup & replication (I’ve developed my own Docker container for this).
  • Using Postfix as a relay for services like Mandrill for reliable transactional email delivery.
  • Nginx, Unicorn, Upstart for reliably running apps with hot reloads on deploys.
  • Infrastructure monitoring using Zabbix (I’ve got my own container for that too).
  • Recovery from a failed disk in software RAID environment.
  • Setting up rate limiting and basic DDOS attack precautions.
  • Defending against small attacks like spam bots, password guessers, etc.

All of these skills translate and support my software development and application design, as I’m much more aware of the whole lifecycle of an application, and the real world usage scenarios that will be thrown at it.