Ask for Help

“I am trying to use the Headless gem to run my selenium tests via an xvfb session on an ubuntu machine. The xvfb session is being launched correctly on display port 99 screen 0 but I am getting the following error from selenium:”

18:08:31.410 ERROR - Failed to start new browser session, shutdown browser and clear all session data
org.openqa.selenium.server.RemoteCommandException: timed out waiting for window 'null' to appear

“here is how I am running Headless:”

require 'headless'
headless = Headless.new
puts "starting Headless session on display: #{headless.display}"
headless.start
begin
  puts "rake spec:integration"
  Rake::Task['spec:integration'].execute
ensure
  puts "stopping Headless"
  headless.destroy
end

Has anybody out there had any luck with this?

Interesting Things

• Using Sunspot with Rails 3 and its rake tasks running a little slow?
  • Adding require ‘sunspot/rails/tasks’ to your Rakefile sounds like a great idea, but a couple of pivots found out that it can unintentionally cause Sunspot to index twice when the rake task was run.
  • The core issue is that Rails 3 automatically finds the rake tasks when the gem is included in your bundle.
• It’s the Year of the Rabbit!

Ask for Help

“Tellurium? Has anybody heard of Tellurium? Bueller?”

Apparently no one at standup had heard about Tellurium which is apparently a “UI module-based web automated testing framework” that “runs on top of Selenium“

“How do I get Bundler to uninstall old versions of gems from the system when new versions get out?”

Turns out that when a gem gets upgraded, bundle install does not necessarily kill the old gems on the system, even when using RVM gemsets. Which can be problematic if you have other systems which are expecting only the newest version of the gem installed.

The easy answer is to prepend bundle exec for every command you want to use. If you’re too lazy for that, then the simplest answer we could come up with was just to blow away your gemset before you deploy.

“Any more admin UI help?”

People are always looking for easy database admin panels for Rails projects. Last week and again today, the new kid on the block, Typus was brought up. Also mentioned today was admin_data.

Some even say the best admin available for a Rails project is actually Django.

Ask for Help

“Does my Rails application on top of Passenger get blocked when I upload a file?”

Nope! Passenger uses plain old apache to buffer the file upload so your application instance is free to service other requests while the upload is finishing.

Ask for Help

Some pivots are trying to import a large number of images into paperclip, and it seemed to hang when shelling out to convert at different images.

Suggestions for troubleshooting included:

• look at the memory usage over the course of the import
• try running one file many time to see if it’s just some bad images

Ask for Help

A pivot was looking for help with using mod_proxy on apache. It only seemed to want to proxy the root.

The only real suggestion available was to use HAProxy instead, but that wasn’t an option for this project

Some pivots were looking for help using bundler together with capistrano, but without rvm.

No real suggestions on what the problem could be.

Some pivots were wondering how long of a time-box they should set aside to get jasmine running in CI.

Consensus was that it should only take about a half-hour.

Interesting Things

• A pivot noticed that the battery life on his MacBook Air seemed to suddenly drop from about 8 hours down to only 4 hours. After some digging through top, it turned out that running rails server and rake jasmine:ci were causing the machine to never be able to fully enter sleep/hibernate to save battery life. So remember to turn those off when you put your laptop away.

Ask for Help

Some pivots were looking for experts with google analytics.

A pivot or two has had experience. Splunk was also suggested as a way to get some potentially different analytics, but warnings were given that it can take a while to get everything set up for Splunk to work correctly.

Interesting Things

• Typus allows easily adding the ability for admin users to edit structured content in your rails app.

• OpenSource Women’s Leadership summit is this Friday. See here for tickets. And check this out for more info

Ask for Help

How do you customize the body of the email message in ActionMailer 3.0? Some pivots want an admin user to be able to edit the default version of the email to be sent, but ActionMailer 3.0 no longer allows the body to be set directly.*

One suggestion was to create a new model that has a default body, and allow the admin user to edit and save, and use that to render the body of the email.

Can you require Bundler inside of the same script that is installing it?

No real solutions other that probably trying to look into the Gem API

Interesting Things

• Amazon has released an email API for sending emails using their servers. Prices start at 10 cents per 1000 messages sent, with breaks for messages coming from within EC2

Ask For Help

We’re running into a problem where MongoMapper is somehow setting the value of a ‘many’ relationship to null in the parent document, which then makes MongoMapper blow up when trying to load the parent doc from mongo. There’s an argument to be made that MongoMapper shouldn’t blow up, but it’s understandable that it’s confused when the key exists – here’s a spec demonstrating what happens when the null exists in
mongo: https://gist.github.com/779930

The big question is what is creating these values. All our inserts are through MongoMapper, so we’re blaming a bug we can’t reproduce in MongoMapper for the moment.

Interesting Things

How to fill up your Redis instance (part 2). Resque stores all records of failed jobs – including full backtraces – on Redis. Pushing a bug that generates lots of these can rapidly fill up your Redis instance. The solution? Send your Resque errors directly to hoptoad (which has better error management infrastructure anyway).

Interesting Things

• How do you know if you’re exceeding your memory allocation on Redis? Resque stops processing! All your workers stop! (That’s how you know).

• Fuubar – an RSpec formatter with:

  • A nifty progress bar to tell you how much longer your spec suite is going to take.
  • Instant reporting of failed tests — fix your source before your tests finish!

To get it running:

$ gem install fuubar
$ repsec --format Fuubar --color spec

Interesting Things

Kevin Kelly, Founding Executive Editor of Wired Magazine and noted technologist will be at Pivotal Labs tomorrow (Thursday January 13th, 2011) at 6:30pm to talk about his latest book What Technology Wants.

For details look here.