Undefined method or attribute error in a Chef recipe

There are multiple reasons Chef can display the following error message

NoMethodError
 -------------
 Undefined method or attribute `...' on `node'

 

There are multiple ways to reference an attribute in a Chef recipe:

node['ATTRIBUTE_NAME'] (the recommended way)
node["ATTRIBUTE_NAME"] 
node[:ATTRIBUTE_NAME]  ( use it only if the single or double quotes (' or ") would cause a problem in the expression)

node.ATTRIBUTE_NAME

To check if the attribute value is nil, use the following format:

if ( !node['ATTRIBUTE_NAME'].nil? )
   ...
end

If you use the node.ATTRIBUTE_NAME format and the value is nil Chef throws the above error message.

SSL certificate is missing after installing ChefDK

When you install a new version of ChefDK and try to run Test Kitchen converge you may get the following error message
>>>>>> ------Exception-------
>>>>>> Class: Kitchen::ActionFailed
>>>>>> Message: Failed to complete #create action: [SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed

To solve the problem add the following to the Windows environment variables and open a new Command or Bash window for the change to take effect:
SSL_CERT_FILE=C:\opscode\chefdk\embedded\ssl\certs\cacert.pem

Winrm is missing after installing ChefDK

When you install the new version of ChefDK you may get the following error message when you try to run Test Kitchen
!!!!!! The `winrm` gem is missing and must be installed or cannot be properly activated. Run `gem install winrm --version '["~> 1.6"]'` or add the following to your Gemfile if you are using Bundler: `gem 'winrm ', '["~> 1.6"]'`.

To install Winrm for the correct Ruby version execute
gem install winrm
gem install winrm-fs

Berkshelf is missing after installing ChefDK

When you install a new version of ChefDK and try to run Test Kitchen the following error message may appear
!!!!!! The `berkshelf' gem is missing and must be installed or cannot be properly activated. Run `gem install berkshelf` or add the following to your Gemfile if you are using Bundler: `gem 'berkshelf'`.

To reinstall Brekshelf in the correct version of Ruby execute
gem install berkshelf

EC2 driver is missing after installing ChefDK

After installing a new version of ChefDK you may get the following error message when you try to run Test Kitchen:

Message: Could not load the 'ec2' driver from the load path. Please ensure that your driver is installed as a gem or included in your Gemfile if using Bundler.

To install the EC2 driver in the correct Ruby version execute

gem install kitchen-ec2

Error in Test Kitchen after installing ChefDK

You may get the following error when you try to run Test Kitchen after installing the latest version of ChefDK:

$ kitchen
C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require': cannot load such file -- dl/import (LoadError)
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/authentication/pageant.rb:1:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/authentication/agent/socket.rb:5:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/authentication/agent.rb:22:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/authentication/key_manager.rb:4:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/authentication/session.rb:4:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh.rb:11:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/test-kitchen-1.7.3/lib/kitchen/ssh.rb:20:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/test-kitchen-1.7.3/lib/kitchen.rb:46:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/test-kitchen-1.7.3/lib/kitchen/cli.rb:21:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/test-kitchen-1.7.3/bin/kitchen:10:in `<top (required)>'
from C:/Ruby22/bin/kitchen:23:in `load'
from C:/Ruby22/bin/kitchen:23:in `<main>'

To make Test Kitchen work again execute the following:

gem install net-ssh -v 2.9.3.beta1

Extract data from JSON with Ruby

Chef uses Ruby as the scripting language. If you need to extract data out from a JSON string you can use the following script


# Save the JSON values
instance_data_drive_config = '{"size":"500","type":"io1","iops":"15000"}'

# Parse the JSON to a hash
data = JSON.parse(instance_data_drive_config)

# Declare the variables
size = ''
type = ''
iops = ''

# Iterate through the hash
data.each do |child|
case child[0]
when 'size'
size = child[1]
when 'type'
type = child[1]
when 'iops'
iops = child[1]
end
end

# Display the result
puts "size=#{size}"
puts "type=#{type}"
puts "iops=#{iops}"

The output is
size=500
type=io1
iops=15000