blender-chef Knife Plugin

Blender chef provides blender and chef integration. It enabled blender to do host discovery based on Chef searches. It also provides `knife blend` plugin that allows running a local recipe against a set of remote servers.

Install & Usage Instructions

Blender-Chef

A chef based host discovery plugin for Blender

Installation

  gem install blender-chef

Usage

With blender-chef, host list for blender jobs can be automatically
fetched from Chef server. Following is an example of dynamically obtaining
all servers with db role, and enlisting their iptables rule.

require 'blender/chef'
config(:chef, chef_sever_url: 'https://foo.bar.com', node_name: 'admin', client_key: 'admin.pem')
members(search(:chef, 'roles:db'))
ssh_task 'sudo iptables -L'

Aany valid chef search can be used. You can pass the node_name, chef_server_url and client_key for chef server config.
ruby
config(:chef, node_name: 'admin', client_key: 'admin.pem', chef_server_url: 'https://example.com')
members(search(:chef, 'ec2_local_ipv4:10.13.12.11'))
ssh_task 'sudo iptables -L'

Alternatively, you can also use a config file lile client.rb or knife.rb
ruby
config(:chef, config_file: '/etc/chef/client.rb')
members(search(:chef, 'roles:db'))


By default blender-chef will pass the FQDN of chef nodes as member list,
in this case as ssh targets. This can be customized by passing the attribute
option.

config(:chef, node_name: 'admin', client_key: 'admin.pem')
members(search(:chef, 'roles:db', attribute: 'ec2_public_ipv4'))

Knife integration

Blender-chef comes with a knife plugin that allows job or chef recipe
execution from CLI.

• Running raw blender jobs Given the following job present in file jobs/upgrade_chef.rb

  ssh_task 'sudo apt-get remove chef --purge'
  ssh_task 'sudo apt-get remove chef --purge'
  ssh_task 'wget -c https://opscode-omnibus-packages.s3.amazonaws.com/ubuntu/13.04/x86_64/chef_12.0.3-1_amd64.deb'
  ssh_task 'sudo dpkg -i chef_12.0.3-1_amd64.deb'
  ssh_task 'sudo chef-client'

It can be executed against all chef nodes having db role as:

  knife blend --search 'roles:db' jobs/upgrade_chef.rb

• Running local one-off chef recipes against remote nodes using blender Given the following chef recipe present ina local file recipes/nginx.rb

  package 'nginx'
  service 'nginx' do
    action [:start, :enable]
  end

It can be executed against all chef nodes having web role as:

  knife blend --recipe-mode --search 'roles:web' recipes/nginx.rb

In --recipe-mode blender will treat the input file(s) as chef recipe
and build necessary scp and ssh tasks to upload the recipe, execute it
and remove the uploaded recipe.

Additional options are provided to control strategy, ssh credentials etc.