pieter michels

Our first #vimcamp & #termcamp (Taken with Instagram at...

Thu, 10 May 2012 11:44:59 +0200

Our first #vimcamp & #termcamp (Taken with Instagram at Proximity BBDO)

Free your Mac OSX memory with `purge`

Wed, 09 May 2012 16:50:00 +0200

Since Mac OSX Lion, my system got low on free memory from time to time. I have 8 Gb of RAM, but that’s not always enough, or so it seems.
To stop your system from using swap files, you can free your memory with the `purge` command.

And it helps to run it every couple of minutes; no worries anymore.

Use this a launchctl task:

VirtualBox virtual machine client connecting to host and Internet

Tue, 08 May 2012 18:53:02 +0200

From time to time, I run an Ubuntu virtual host on my Mac OSX machine (in VirtualBox) for testing and trying. It took me a while to figure out how to setup this virtual machine so it has access to the Internet as well as local access to my host.

For referencial purposes, here goes:

VirtualBox settings

In your VirtualBox preferences, add a ‘host-only network’ (vboxnet0).

Adapter Settings:

IPv4 address: 192.168.56.1

IPv4 Network Mask: 255.255.255.0

DHCP Server:

Server Address: 192.168.56.100

Server Mask: 255.255.255.0

Lower Address Bound: 192.168.56.101

Upper Address Bound: 192.168.56.254

Make sure you have your VirtualBox instance set up with two networks interfaces:

NAT (1)
and Host-only (2).

Default settings are ok.

Ubuntu settings

Execute this:

$ bash <( curl -s https://raw.github.com/pierot/server-installer-lokal/master/make-headless.sh ) [-i '192.168.56.5']

It will add the network interface for your local connection. You can now ssh into your Linux.

Headless

If you want to make your installation headless, you can use the following:

$ sudo apt-get install ssh openssh-server

$ sudo mv /etc/init/gdm.conf /etc/init/gdm.conf.disabled

$ sudo reboot

Ships and Tools | Trends

Thu, 12 Apr 2012 13:12:52 +0200

Ships and Tools | Trends:

Food for thought.

therubyracer compile error OSX 10.7 Lion

Fri, 09 Mar 2012 10:50:00 +0100

I ran into some erros while compiling the therubyracer gem after an update to Mac OSX Lion. It threw errors like this:

Most of the solutions on Github and other blogs didn’t work for me. Eventually I fixed it with the following commands:

Install latest v8 library through Homebrew

Install libv8 gem

Symlink gcc binary to gcc-4.2 binary:

(this was probably the real solution)

How to login to postgresql through psql from a linux user

Mon, 23 Jan 2012 20:36:00 +0100

How to login to postgresql through psql from a linux user:

If you get these errors while trying to access your PostgreSQL database through ‘psql’:

psql: FATAL: Peer authentication failed for user “postgres”

This was exactly what I was looking for.
So I updated my postgreSQL install script.

RVM loses default Ruby version when starting new shell

Mon, 23 Jan 2012 20:34:15 +0100

I recently installed a new Ruby version on a server using RVM. To make sure your new ruby installation will be used by default, you have to invoke the follow command:

(I already blogged about this)

But now, my server kept forgetting this and each time I ssh’ed to the server (and thus starting a new shell) I was back at the default system Ruby version.

It seems you can repair your RVM environments (I didn’t know I broke something in the first place?):

Varnish Guru Meditation

Mon, 02 Jan 2012 17:28:55 +0100

I had a problem where a Rails application communicated with a third-party API (Dropbox) to do some actions. The request would take significantly more time than a regular request, lasting for more than 15 second easily (fetching numerous directories and files).
Your browser won’t timeout on such requests, but in my case, Varnish was. It would serve me with the following message:

Clearly this is a safeguard of Varnish. It’s easy to fix this with a settings change in your ‘vim /etc/varnish/default.vcl’ file.

Linode rocks

Thu, 29 Dec 2011 14:45:49 +0100

Linode rocks:

I’ve been using Linode to host my websites for the past 2+ years and I’m thoroughly impressed by the service. I can’t recommend them enough — it is easily the best web hosting service I’ve used to date.

Couldn’t agree more.

PDFKit Usage

Wed, 28 Dec 2011 08:31:55 +0100

PDFKit Usage:

Wkhtmltopdf is an open source project that uses the WebKit rendering engine to convert HTML to native PDF code. This is the muscle behind the PDFKit gem and other projects like WickedPdf. In this article I am only going to focus on PDFKit with Rails. But many topics will apply to both PDFKit and WickedPdf since they use wkhtmltopdf on the backside.

Great guide for starting with PDFKit.

VirtualBox Linux local networking

Thu, 01 Dec 2011 08:51:00 +0100

From time to time, I run an Ubuntu virtual host on my Mac OSX machine (in VirtualBox) for testing and trying. It took me a while to figure out, how to setup this virtual machine so it has access to the Internet as well as local access to my host.

For referencial purposes, here goes:

In your VirtualBox preferences, add a ‘host-only network’ (vboxnet0).

Adapter Settings:

DHCP Server:

Make sure you have your VirtualBox instance set up with two networks interfaces: NAT (1) and Host-only (2). Default settings are ok.

On your Ubuntu guest:

And then restart your networing.

Additionally, I configure my local Linux machine as a headless OS, as a result I only access it through SSH.

And reboot

The twelve-factor methodology

Wed, 23 Nov 2011 14:35:00 +0100

The twelve-factor methodology:

In the modern era, software is commonly delivered as a service: called web apps, or software-as-a-service. The twelve-factor app is a methodology for building software-as-a-service apps that:

Use declarative formats for setup automation, to minimize time and cost for new developers joining the project;

Have a clean contract with the underlying operating system, offering maximum portability between execution environments;

Are suitable for deployment on modern cloud platforms, obviating the need for servers and systems administration;

Minimize divergence between development and production, enabling continuous deployment for maximum agility;

And can scale up without significant changes to tooling, architecture, or development practices.

Source: http://www.12factor.net

Default Passenger user and permissions

Tue, 08 Nov 2011 13:44:00 +0100

Quick note to self.

If you deploy a Rails application (with Capistrano for instance) to a Passenger / nginx server, you have to make sure you don’t deploy the app as user ‘root’ (I hear people say ‘never ever use root!’ … oh well).

Why not?
Passenger will run your Rails application as the user who owns the config/environment.rb file (see help). If the owner of this file is ‘root’, the user is switched to the default Passenger user, which is by default ‘nobody’.
This might result in insufficient permissions for actions like writing to a database file or when compiling assets.

Gitlab, self-hosted git server and browser

Tue, 25 Oct 2011 14:14:00 +0200

Gitlab, self-hosted git server and browser:

Gitlab might finally be the front-end for a self-hosted git server. I’ve lost countless hours trying to install Gitalist and had too many ugly systems installed. But, no more, I hope.

(Gitolite support will be available in v 2.0)

Kindle Format 8

Mon, 24 Oct 2011 20:35:02 +0200

Kindle Format 8:

We’re pleased to announce a wide range of new features and enhancements – including HTML5 support – coming in Kindle Format 8 (KF8). KF8 is the next generation file format for Kindle books – replacing Mobi 7. As showcased on Kindle Fire, KF8 enables publishers to create great-looking books in categories that require rich formatting and design such as children’s picture books, comics & graphic novels, technical & engineering books and cookbooks. Kindle Format 8 replaces the Mobi format and adds over 150 new formatting capabilities, including fixed layouts, nested tables, callouts, sidebars and Scalable Vector Graphics, opening up more opportunities to create Kindle books that readers will love.

Seems like great news to me. Although I doubt the new format will be available on the slightly older Kindle devices, not so great news.

Building an installation together with Jeroen Bourgois,...

Fri, 14 Oct 2011 14:40:24 +0200

Building an installation together with Jeroen Bourgois, using Arduino and WiFly Shield.

Amazon on fire

Mon, 03 Oct 2011 09:35:00 +0200

For over 6 months now, I’ve been very happy with my Kindle 3G. It is a second generation one, with a keyboard. Being very lightweigt, having a long battery life and a fantastic screen (you have to see it before you know what I mean) is what still excites me everytime I use it. You see, I became somewhat of a Kindle / Amazon fan-boy!

And now, Amazon updated its Kindle line-up with the addition of 3 new (dedicated) e-readers: Kindle, Kindle Touch and Kindle Touch 3G. Even more lightweight and smaller.
If you were still unsure whether to buy one or not: don’t hestitate, go get one now (but know which one to choose :))! You’ll be very pleased with it, as I have been for the past months.

When owning a Kindle, living in Belgium has some downsides. You’re still dependend on the Amazon book / Kindle store for your books and it doesn’t contain much literature in dutch. So for now, this is my main medium for all my technical books and some international writers. There are some options to buy on a store like Bol.com and than convert the book … but that’s down a ‘non-legal’ road and that might be too much of a hastle. Buying on Amazon.com is as simple as hitting the Buy button and your book is delivered automatically and via WiFi or Whispernet (world-wide data connection).

But besides that: I’m all for the Amazon Kindle product-line.

Last but not least, Amazon announced the Kindle Fire. An Android based tablet with a strong focus on movies, music and books. Might seem an attractive (and maybe only decent) alternative to an iPad .. time will tell.

"The Mythical Man-Finger. faster, easier to understand, easier to integrate, more scalable, more..."

Tue, 27 Sep 2011 16:41:00 +0200

“

The Mythical Man-Finger.

faster, easier to understand, easier to integrate, more scalable, more portable, more sustainable, more consistent, and many, many times more flexible than even the most well-thought-out graphical apps.

”

- http://j.mp/ofkcdS

Stock quotes as a Ruby library or via your command line: Stockery

Thu, 22 Sep 2011 21:33:00 +0200

Stockery, a simple Ruby gem that allows you to query stock quotes from (for now) the Google API or Yahoo Finance API. The nice thing is that you can use it as a library inside your project, or just via the command line and mix & mash it with your favourite shell script.

Usage via command line

By default stockery outputs a JSON format of the result fetched from Google.

Fetch GOOG quote via Yahoo.

Set the output to print and it prints it directly to your prompt.

Multiple stock symbols.

Help :)

Usage through Ruby

Rack-webconsole, a console inside your browser

Fri, 29 Jul 2011 12:54:00 +0200

“Wouldn’t it be nice to have an in-browser console for a Rails application?”

Introducing rack-webconsole

Rack-webconsole is a Rack middleware that enhances your development experience providing a JavaScript-powered bridge to your Ruby application backend.

With it you can interact with your database and explore the runtime environment from within the browser. Although it should be used mainly in development environments, I personally think it could be a useful tool for staging as well. Avoids the pain in the ass of interacting with some console over an SSH session :)

via blog.codegram.com

This one is really useful. It keeps you in your browser window while debugging an application.