obfuscurity.
hidden in plain sight

I recently found myself in the need for a way to run a one-off Ruby script at scheduled intervals. As this is a work project I didn't just want to run it on my laptop or some random server. Turns out there's an easy way to run this for free on the Heroku Cedar platform without having to piggyback it on a "real" application. Because there are no web processes running, we'll be able to limit our dyno usage to a single dyno (in other words, it's free).

The script itself handles garbage collection duties for removing expired hosts off our beta account with Boundary. Basically I just want it to run every hour and cull anything that hasn't reported to their collectors in a day. For the purpose of this article the contents of the script are inconsequential, although I intend to present it fully in a future post.

To run your own scheduled Ruby code, you'll first need to create Gemfile and Gemfile.lock files. These Bundler files are used by the Cedar platform to determine that you need the Ruby buildpack.

$ cd oscar

$ ls -l
total 16
-rw-r--r--  1 jdixon  jdixon   47 Feb 11 09:25 Gemfile
-rw-r--r--  1 jdixon  jdixon  189 Feb 11 09:25 Gemfile.lock

bin:
total 8
-rw-r--r--  1 jdixon  jdixon  954 Feb 11 09:25 purge_meters

You'll want to initialize your git repo (if you haven't already) and commit. Create a new Heroku app and add push it to the Heroku git server.

$ git init .
Initialized empty Git repository in /Projects/oscar/.git/

$ git add .

$ git ci -m "initial commit"
[master (root-commit) 41ec621] initial commit
 3 files changed, 56 insertions(+), 0 deletions(-)
 create mode 100644 Gemfile
 create mode 100644 Gemfile.lock
 create mode 100644 bin/purge_meters

$ heroku create -s cedar
Creating blooming-robot-7955... done, stack is cedar
http://blooming-robot-7955.herokuapp.com/ | [email protected]:blooming-robot-7955.git
Git remote heroku added

$ git push heroku master
Counting objects: 6, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (4/4), done.
Writing objects: 100% (6/6), 1002 bytes, done.
Total 6 (delta 0), reused 0 (delta 0)

-----> Heroku receiving push
-----> Ruby app detected
-----> Installing dependencies using Bundler version 1.1.rc.7
       Running: bundle install --without development:test --path vendor/bundle 
         --binstubs bin/ --deployment
       Fetching gem metadata from http://rubygems.org/..
       Installing json (1.6.4) with native extensions
       Installing mime-types (1.17.2)
       Installing rest-client (1.6.7)
       Using bundler (1.1.rc.7)
       Your bundle is complete! It was installed into ./vendor/bundle
       Cleaning up the bundler cache.
-----> Discovering process types
       Procfile declares types -> (none)
       Default types for Ruby  -> console, rake
-----> Compiled slug size is 1.5MB
-----> Launching... done, v4
       http://blooming-robot-7955.herokuapp.com deployed to Heroku

To [email protected]:blooming-robot-7955.git
 * [new branch]      master -> master

Next, add the Scheduler addon to your app.

$ heroku addons:add scheduler:standard
-----> Adding scheduler:standard to blooming-robot-7955... done, v5 (free)
       This add-on consumes dyno hours, which could impact your monthly bill.
       To learn more:
       http://devcenter.heroku.com/addons_with_dyno_hour_usage
       To manage scheduled jobs run:
       heroku addons:open scheduler

Now you'll need to specify the task you want to run (your Ruby script). Run the following command to open the Scheduler dashboard in your default web browser.

$ heroku addons:open scheduler
Opening scheduler:standard for blooming-robot-7955...

Click the Add Job... link to edit your task command. For my task I wanted to run the script with bundle exec ruby. Choose your Frequency, optionally select the Next Run time, and then Save. Once this is saved you can also click the Run button to run the job manually and look for any errors in the Task Output.

Voila, you have your own free cron job running through the wonders of THE CLOUD. Now go off and conquer the world!

This evening I asked for your suggestions on blocking online distractions, allowing me to focus on code for an extended period of time. I have a constant struggle with interruptions (read: shiny things) including online news, email and Twitter. There was a flood of responses in no time. Here are the more popular suggestions, along with my winners below.

• quit the offending apps
• block websites
• login with a different user
• work offline
• coffee
• music
• self-control (lol rite)

I suspect that all of these would have some benefit, perhaps except coffee, which has never given me much of a boost anyways. As a side note, I've quit Diet Coke since my surgery and am exclusively drinking water. So it's possible that coffee might give me an insanely productive hit, but I'm not willing to tread that path yet. Here are the specific steps I took which seemed to work quite well for my particular workflow.

1. quit Twitter app
2. quit Chrome (primary browser)
3. quit Firefox (used for HTML email, Facebook and banking)
4. quit Propane (Campfire app, work communications)
5. quit Adium
6. quit Skype
7. detached my remote screen session (mutt and irssi)
8. equipped Sony MDR-V6 headphones
9. launched Spotify radio (trance)
10. put iTerm2 in full-screen mode (used for psql, git and debugging development server)
11. put MacVim in full-screen mode
12. launched Safari for API docs and development site

I'm pleased with the recent experiment, even if it only lasted one hour. I'll continue to make adjustments and report any significant improvements I find.

Can you get any simpler than this and still call it a sandwich? Belying its simplicity, this rustic combination has excellent texture and flavor. Lay them out on a baguette and call it a day.