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Opscode Chef knife plug-in for EC2
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Knife EC2

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This is the official Chef Knife plugin for EC2. This plugin gives knife the ability to create, bootstrap, and manage EC2 instances.


If you're using bundler, simply add Chef and Knife EC2 to your Gemfile:

gem 'chef'
gem 'knife-ec2'

If you are not using bundler, you can install the gem manually. Be sure you are running Chef 0.10.10 or higher, as earlier versions do not support plugins.

$ gem install chef

This plugin is distributed as a Ruby Gem. To install it, run:

$ gem install knife-ec2

Depending on your system's configuration, you may need to run this command with root privileges.


In order to communicate with the Amazon's EC2 API you will have to tell Knife about your AWS Access Key and Secret Access Key. The easiest way to accomplish this is to create some entries in your knife.rb file:

knife[:aws_access_key_id] = "Your AWS Access Key ID"
knife[:aws_secret_access_key] = "Your AWS Secret Access Key"

If your knife.rb file will be checked into a SCM system (ie readable by others) you may want to read the values from environment variables:

knife[:aws_access_key_id] = ENV['AWS_ACCESS_KEY_ID']
knife[:aws_secret_access_key] = ENV['AWS_SECRET_ACCESS_KEY']

You also have the option of passing your AWS API Key/Secret into the individual knife subcommands using the -A (or --aws-access-key-id) -K (or --aws-secret-access-key) command options

# provision a new m1.small Ubuntu 10.04 webserver
$ knife ec2 server create -r 'role[webserver]' -I ami-7000f019 -f m1.small -A 'Your AWS Access Key ID' -K "Your AWS Secret Access Key"

If you are working with Amazon's command line tools, there is a good chance you already have a file with these keys somewhere in this format:

AWSAccessKeyId=Your AWS Access Key ID
AWSSecretKey=Your AWS Secret Access Key

The new config file format used by Amazon's command line tools is also supported:

aws_access_key_id = Your AWS Access Key ID
aws_secret_access_key = Your AWS Secret Access Key

In this case, you can point the aws_credential_file option to this file in your knife.rb file, like so:

knife[:aws_credential_file] = "/path/to/credentials/file/in/above/format"

Additionally the following options may be set in your knife.rb:

  • flavor
  • image
  • availability_zone
  • aws_ssh_key_id
  • region
  • distro
  • template_file

Using Cloud-Based Secret Data

knife-ec2 now includes the ability to retrieve the encrypted data bag secret and validation keys directly from a cloud-based assets store (currently on S3 is supported). To enable this functionality, you must first upload keys to S3 and give them appropriate permissions. The following is a suggested set of IAM permissions required to make this work:

  "Statement": [
      "Effect": "Allow",
      "Action": [
      "Resource": [

Use the following configuration options in knife.rb to set the source URLs:

knife[:validation_key_url] = 's3://'
knife[:s3_secret] = 's3://'

Alternatively, URLs can be passed directly on the command line:

  • Validation Key: --validation-key-url s3://
  • Encrypted Data Bag Secret: --s3-secret s3://


This plugin provides the following Knife subcommands. Specific command options can be found by invoking the subcommand with a --help flag

knife ec2 server create

Provisions a new server in the Amazon EC2 and then perform a Chef bootstrap (using the SSH or WinRM protocols). The goal of the bootstrap is to get Chef installed on the target system so it can run Chef Client with a Chef Server. The main assumption is a baseline OS installation exists (provided by the provisioning). It is primarily intended for Chef Client systems that talk to a Chef server. The examples below create Linux and Windows instances:

# Create some instances -- knife configuration contains the AWS credentials

# A Linux instance via ssh
knife ec2 server create -I ami-d0f89fb9 --ssh-key your-public-key-id -f m1.medium --ssh-user ubuntu --identity-file ~/.ssh/your-private-key

# A Windows instance via the WinRM protocol -- --ssh-key is still required due to EC2 API operations that need it to grant access to the Windows instance
knife ec2 server create -I ami-173d747e -G windows -f m1.medium --user-data ~/your-user-data-file -x '.\a_local_user' -P 'yourpassword' --ssh-key your-public-key-id

View additional information on configuring Windows images for bootstrap in the documentation for knife-windows.

knife ec2 server delete

Deletes an existing server in the currently configured AWS account. By default, this does not delete the associated node and client objects from the Chef server. To do so, add the --purge flag

knife ec2 server list

Outputs a list of all servers in the currently configured AWS account. Note, this shows all instances associated with the account, some of which may not be currently managed by the Chef server.

License and Authors

Copyright 2009-2014 Opscode, Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
See the License for the specific language governing permissions and
limitations under the License.
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