An overview of Shef, the Chef Shell/debugger.

1. Shef: The Chef Shell
Julian C. Dunn
Senior Systems Operations Engineer
jdunn@secondmarket.com

2. What is SecondMarket?
Since 2004, SecondMarket has been committed to
connecting the world’s qualified investors with
alternative investments.
Our Vision:
To revolutionize the financial markets by creating a Trading
trusted global platform to more efficiently allocate capital Providing institutional investors with access to
through technology-enabled solutions. unique fixed income products, independent
market perspective, and superior client
service
SecondMarket is organized into
three business segments:
Markets
Creating an enterprise solution for private
issuers to help them facilitate secondary
trading and raising primary capital in a
company-controlled manner
neXus
Aggregating, standardizing and promoting
next generation investments to make them
available to the broadest group of investors
ever assembled
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

3. What is Shef?
Chef running within IRB
Three modes:
Standalone ("-a")
Solo ("-s")
Client ("-z")
Use existing config file or shef.rb
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

4. SecondMarket Infrastructure
75-100 servers
Hosting: Amazon EC2
Technologies: Java (Spring MVC), Scala, Play!
Framework, PostgreSQL, Mongo, Redis, Couchbase
Server, ActiveMQ
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

5. Main Uses of Shef
Quick prototyping
Syntax checking
Debugging recipes
Poke around Chef Server in familiar
Ruby environment
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

6. Shef Standalone Demo
6

7. Commands and Modes
Default prompt
Attribute mode
Recipe mode
Run Chef
Other useful commands
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

8. Debugging Recipes
8

9. Summary
Setting breakpoints
chef_run.rewind
chef_run.skip_forward and
skip_backwards
resources command
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

10. Using Shef as a Client
10

11. Shef as a Client
Interactive testing of node searches
Step through one or more recipes
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

12. Debugging Production
Issues
12

13. HipChat Chef Room
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

14. zones.erb
29: <% @members.each do |member| -%>
30: <%= member['hostname'] %> IN
CNAME
<%= member['ec2']['public_hostname'] %>.
31: <% end -%>
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

15. Which member is causing this
to screw up?
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

16. Which member is causing this
to screw up?
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

17. [jdunn@dns1 ~]$ shef -z
loading configuration: /etc/chef/client.rb
Session type: client
.
.
chef > echo off
chef > members = search('node', "domain:epicfail.com")
chef > members.each do |m|
chef > pp "#{m['hostname']}, #{m['ec2']
['public_hostname']}"
chef ?> end
"host1, ec2-50-17-43-13.compute-1.amazonaws.com"
"host37, ec2-23-23-145-243.compute-1.amazonaws.com"
"host3, "
NoMethodError: undefined method `[]' for nil:NilClass
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

18. Limitations of Shef
Can’t modify run list w/o resetting
Attributes mode changes don’t propagate to recipes
Client mode can't operate on local cookbooks - must
upload to the server (just like a regular Chef client)
And yes, the name is confusing. It’s being changed: http://
tickets.opscode.com/browse/CHEF-2925
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

19. Thanks!
@julian_dunn
jdunn@secondmarket.com
http://engineering.secondmarket.com/
Yes, we’re hiring!
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.

20. Disclosure
This document is intended for those with an in-depth understanding of the high risk nature of alternative investments and these
investments may not be suitable for you. This document may not be distributed in either excerpts or in its entirety beyond its intended
audience and SecondMarket will not be held responsible if this document is used or is distributed beyond its initial recipient or if it used
for any unintended purpose. This document is not a solicitation for an order, and there is not enough information contained in this
message in which to make an investment decision and any information contained herein should not be used as a basis for this purpose.
To the best of our knowledge, this document and relevant pages are: current as of the date of distribution; subject to change without
notice; directed solely at eligible institutional buyside and/or sellside clients, qualified purchasers, qualified institutional brokers and other
professional clients; not directed at, may not be suitable for and should not be relied on by general retail clients.
SecondMarket does not: produce in-house research; make recommendations to purchase or sell specific securities; provide investment
advisory services; and conduct a general retail business.
By reading this document you acknowledge that you are not a general retail client. If you are a general retail client then this document is
not intended for you. Alternative investments may not be suitable investments for you and you may not possess the sophistication to rely
on its contents and should either shred or return to SecondMarket.
Neither SecondMarket, its affiliates, nor any of its directors, officers, employees or agents shall have any liability, howsoever arising, for
any error or incompleteness of fact or opinion in it or lack of care in its preparation or publication; provided that this shall not exclude
liability to the extent that this is impermissible under securities laws. All statements and opinions are liable to change without notice.
The SecondMarket logos, graphics, icons, trademarks, service marks and headers appearing herein are service marks, trademarks
(whether registered or not) and/or trade dress of SecondMarket Holdings, Inc. (the “Marks”). All other trademarks, company names,
logos, service marks and/or trade dress mentioned, displayed, cited or otherwise indicated herein (“Third Party Marks”) are the sole
property of their respective owners. The Marks or the Third Party Marks may not be copied, downloaded, displayed, used as metatags,
misused, or otherwise exploited in any manner without the prior express written permission of SecondMarket or the owner of such Third
Party Mark.
Member FINRA | MSRB | SIPC © 2012 SecondMarket Holdings, Inc.