wesley tanaka


Making directory trees equivalent to mkdir -p in puppet


When you create a directory in Puppet using the file type, you may get this error if you haven't already created all parents of the directory in question first:

err: /Stage[main]//File[/path/to]/ensure: change from absent to directory failed: Cannot create /path/to; parent directory /path does not exist

This puppet module defines a custom function all_parents() which you can use to create a directory and all of its ancestors simultaneously.

Install ruby gems without root access in your home directory


You can install a ruby gem in your home directory with:

gem install --user-install puppet-module 


gem install --install-dir=$HOME/.gem/ruby/1.8 puppet-module

If you're using bundler:

bundle install --path $HOME/.gem

And then you can run the command line programs installed by adding the local bin directory to your path:

export PATH

Using celery with SQS


Some notes about using celery with SQS:

  • acks_late does not seem to work
  • sending a task that's larger than the SQS message size limit fails with <?xml version="1.0"?><Error><Type>Sender</Type><Code>InvalidParameterValue</Code><Message>Value for parameter MessageBody is invalid. Reason: Message body must be shorter than 262144 bytes.</Message><Detail/></Error>

MessagePack vs JSON vs BSON


Here is a benchmark of MessagePack vs JSON vs BSON in Python 2.7.3 in Ubuntu 12.04.4 LTS on a 2.5 GHz Intel Core2 Quad Q8300. The software used was:

Install python packages without root access using easy_install or pip


You can run easy_install to install python packages in your home directory even without root access. There's a standard way to do this using site.USER_BASE which defaults to something like $HOME/.local or $HOME/Library/Python/2.7/bin and is included by default on the PYTHONPATH

To do this, create a .pydistutils.cfg in your home directory:

Create MySQL hashed password for Puppet password_hash setting


To generate a password_hash for a MySQL user in the puppetlabs-mysql Puppet Forge module, run the mysql command line program and run the query SELECT PASSWORD('opensaysme'); where opensaysme is the password you want to use for the MySQL user. For example:

Switching from GoDaddy.com to Namecheap.com


Years ago, I registered a few domain names with GoDaddy under their cheap promotional pricing. Every year since, I've wanted to transfer my domains away from GoDaddy to avoid their jacked up renewal fees, but every year I'd procrastinate until the expiration date and, out of fear that the transfer would fail and I'd lose the domain names entirely, I'd end up searching online for a coupon, biting the bullet, and renewing with them.  Last year, I tried to switch to 1&1 but they did not support wildcard domain names, so I gave up.

Implied State Space Size


Consider these two if statements:

If statement #1

if (color == RED and has_thorns == TRUE)
  return "Roses are red"
else if (num_petals == 5)
  return "Violets are blue"

If statement #2

if (species == ROSE)
  return "Roses are red"
else if (species == VIOLET)
  return "Violets are blue"

The Architecture of Open Source Applications ePub download


You can download an ePub version of "The Architecture of Open Source Applications" (edited by Amy Brown and Greg Wilson) here.

The book is also available to read for free at http://aosabook.org/en/index.html under the Creative Commons Attribution 3.0 Unported license.

Using Eclipse with a Android project using the new gradle build system / project structure / layout


The Eclipse Android ADT plugin hard-codes paths for the AndroidManifest.xml file, the res directory and the gen directory.  If you migrate an Android project to the new Gradle project structure, it will stop working in Eclipse.  You can work around this by creating symbolic links from the new Gradle layout to the old locations expected by ADT.  For example, from the root of your project, if you have a android directory, you can run these commands:

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by Wesley Tanaka