knife bootstrap

A node is any physical, virtual, or cloud machine that is configured to be maintained by a chef-client. A bootstrap is a process that installs the chef-client on a target system so that it can run as a chef-client and communicate with a Chef server. There are two ways to do this:

• Use the knife bootstrap subcommand to bootstrap a node using the omnibus installer
• Use an unattended install to bootstrap a node from itself, without using SSH or WinRM

Use the knife bootstrap subcommand to run a bootstrap operation that installs the chef-client on the target system. The bootstrap operation must specify the IP address or FQDN of the target system.

Note

To bootstrap the chef-client on Microsoft Windows machines, the knife-windows plugins is required, which includes the necessary bootstrap scripts that are used to do the actual installation.

Syntax

This subcommand has the following syntax:

$ knife bootstrap FQDN_or_IP_ADDRESS (options)

Options

Note

Review the list of common options available to this (and all) knife subcommands and plugins.

This subcommand has the following options:

-A, --forward-agent

Enable SSH agent forwarding.

--bootstrap-no-proxy NO_PROXY_URL_or_IP

A URL or IP address that specifies a location that should not be proxied.

Note

This option is used internally by Chef to help verify bootstrap operations during testing and should never be used during an actual bootstrap operation.

--bootstrap-proxy PROXY_URL

The proxy server for the node that is the target of a bootstrap operation.

--bootstrap-version VERSION

The version of the chef-client to install.

-d DISTRO, --distro DISTRO

The template file to be used during a bootstrap operation. The following distributions are supported:

• chef-full (the default bootstrap)
• centos5-gems
• fedora13-gems
• ubuntu10.04-gems
• ubuntu10.04-apt
• ubuntu12.04-gems
• The name of a custom bootstrap template file.

When this option is used, knife searches for the template file in the following order:

1. The bootstrap/ folder in the current working directory
2. The bootstrap/ folder in the chef-repo
3. The bootstrap/ folder in the ~/.chef/ directory
4. A default bootstrap file.

Do not use the --template-file option when --distro is specified.

Warning

The default bootstrap operation uses the omnibus installer, which means the default template file (chef-full) should work on all supported platforms. It is recommended to use custom bootstrap templates only when the omnibus installer cannot be used. The .erb file extension is added automatically and should not be passed as part of the bootstrap command.

-E ENVIRONMENT, --environment ENVIRONMENT

The name of the environment. When this option is added to a command, the command will run only against the named environment.

-G GATEWAY, --ssh-gateway GATEWAY

The SSH tunnel or gateway that is used to run a bootstrap action on a machine that is not accessible from the workstation.

--hint HINT_NAME[=HINT_FILE]

An Ohai hint to be set on the target node.

Ohai hints are used to tell Ohai something about the system that it is running on that it would not be able to discover itself. An Ohai hint exists if a JSON file exists in the hint directory with the same name as the hint. For example, calling hint?('antarctica') in an Ohai plugin would return an empty hash if the file antarctica.json existed in the hints directory, and return nil if the file does not exist.

If the hint file contains JSON content, it will be returned as a hash from the call to hint?.

{
  "snow": true,
  "penguins": "many"
}

antarctica_hint = hint?('antarctica')
if antarctica_hint['snow']
  "There are #{antarctica_hint['penguins']} penguins here."
else
  'There is no snow here, and penguins like snow.'
end

The default directory in which hint files are located is /etc/chef/ohai/hints/. Use the Ohai::Config[:hints_path] setting in the client.rb file to customize this location.

HINT_FILE is the name of the JSON file. HINT_NAME is the name of a hint in a JSON file. Use multiple --hint options to specify multiple hints.

-i IDENTITY_FILE, --identity-file IDENTITY_FILE

The SSH identity file used for authentication. Key-based authentication is recommended.

-j JSON_ATTRIBS, --json-attributes JSON_ATTRIBS

A JSON string that is added to the first run of a chef-client.

-N NAME, --node-name NAME

The name of the node.

--[no-]host-key-verify

Use --no-host-key-verify to disable host key verification. Default setting: --host-key-verify.

-p PORT, --ssh-port PORT

The SSH port.

-P PASSWORD, --ssh-password PASSWORD

The SSH password. This can be used to pass the password directly on the command line. If this option is not specified (and a password is required) knife prompts for the password.

--prerelease

Install pre-release gems.

-r RUN_LIST, --run-list RUN_LIST

A comma-separated list of roles and/or recipes to be applied.

--secret SECRET

The encryption key that is used for values contained within a data bag item.

--secret-file FILE

The path to the file that contains the encryption key.

--sudo

Execute a bootstrap operation with sudo.

--template-file TEMPLATE

The path to a template file to be used during a bootstrap operation. Do not use the --distro option when --template-file is specified.

--use-sudo-password

Perform a bootstrap operation with sudo; specify the password with the -P (or --ssh-password) option.

-x USERNAME, --ssh-user USERNAME

The SSH user name.

Note

See knife.rb for more information about how to add certain knife options as settings in the knife.rb file.

Custom Templates

The chef-full distribution uses the omnibus installer. For most bootstrap operations, regardless of the platform on which the target node is running, using the chef-full distribution is the best approach for installing the chef-client on a target node. In some situations, using another supported distribution is necessary. And in some situations, a custom template may be required. For example, the default bootstrap operation relies on an Internet connection to get the distribution to the target node. If a target node cannot access the Internet, then a custom template can be used to define a specific location for the distribution so that the target node may access it during the bootstrap operation.

For example, a bootstrap template file named “british_sea_power”:

$ knife bootstrap 123.456.7.8 -x username -P password --sudo --distro "british_sea_power"

The following examples show how a bootstrap template file can be customized for various platforms.

Template Locations

A custom bootstrap template file (template_filename) must be located in a bootstrap/ directory, typically located within the ~/.chef/ directory.

Use the --distro option with the knife bootstrap subcommand to specify the bootstrap template file. This location is configurable when the following settings are added to the knife.rb file:

Setting	Description
knife[:distro]	The template file to be used during a bootstrap operation. The following distributions are supported: chef-full (the default bootstrap) centos5-gems fedora13-gems ubuntu10.04-gems ubuntu10.04-apt ubuntu12.04-gems The name of a custom bootstrap template file. When this option is used, knife searches for the template file in the following order: The bootstrap/ folder in the current working directory The bootstrap/ folder in the chef-repo The bootstrap/ folder in the ~/.chef/ directory A default bootstrap file. Do not use the --template-file option when --distro is specified.
knife[:template_file]	The path to a template file to be used during a bootstrap operation. Do not use the --distro option when --template-file is specified.

Ubuntu 12.04

The following example shows how to modify the default script for Ubuntu 12.04. First, copy the bootstrap template from the default location. If the chef-client is installed from a RubyGems, the full path can be found in the gem contents:

$ gem contents chef | grep ubuntu12.04-gems
/Users/jtimberman/.rvm/gems/ruby-1.9.3-p180/gems/chef-0.10.2/lib/chef/knife/bootstrap/ubuntu12.04-gems.erb

Copy the template to the chef-repo in the .chef/bootstrap directory:

$ cp /Users/jtimberman/.rvm/gems/ruby-1.9.3-p180/gems/chef-0.10.2/
   lib/chef/knife/bootstrap/ubuntu12.04-gems.erb ~/chef-repo/.chef/
   bootstrap/ubuntu12.04-gems-mine.erb

Modify the template with any editor, then specify it using the --distro option as part of the the knife bootstrap operation, or with any of the knife plug-ins that support cloud computing.

$ knife bootstrap 192.168.1.100 -r 'role[webserver]' -distro ubuntu12.04-gems-mine

Alternatively, an example bootstrap template can be found in the git source for the chef-repo: https://github.com/chef/chef/tree/master/lib/chef/knife/bootstrap. Copy the template to ~/.chef-repo/.chef/bootstrap/ubuntu12.04-apt.erb and modify the template appropriately.

Debian and Apt

The following example shows how to use the knife bootstrap subcommand to create a client configuration file (/etc/chef/client.rb) that uses Hosted Chef as the Chef server. The configuration file will look something like:

log_level        :info
log_location     STDOUT
chef_server_url  'https://api.opscode.com/organizations/ORGNAME'
validation_client_name 'ORGNAME-validator'

The knife bootstrap subcommand will look in three locations for the template that is used during the bootstrap operation. The locations are:

1. A bootstrap directory in the installed knife library; the actual location may vary, depending how the chef-client is installed
2. A bootstrap directory in the $PWD/.chef, e.g. in ~/chef-repo/.chef
3. A bootstrap directory in the users $HOME/.chef

If, in the example above, the second location was used, then create the .chef/bootstrap/ directory in the chef-repo, and then create the Embedded Ruby (ERB) template file by running commands similar to the following:

$ mkdir ~/.chef/bootstrap

and then:

$ vi ~/.chef/bootstrap/debian5.0-apt.erb

When finished creating the directory and the Embedded Ruby (ERB) template file, edit the template to run the SSH commands. Then set up the validation certificate and the client configuration file.

Finally, run the chef-client on the node using a knife bootstrap command that specifies a run-list (the -r option). The bootstrap template can be called using a command similar to the following:

$ knife bootstrap mynode.example.com -r 'role[webserver]','role[production]' --distro debian5.0-apt

Microsoft Windows

The following example shows how to modify the default script for Microsoft Windows and Windows PowerShell:

@setlocal

<%= "SETX HTTP_PROXY \"#{knife_config[:bootstrap_proxy]}\"" if knife_config[:bootstrap_proxy] %>
@mkdir <%= bootstrap_directory %>

> <%= bootstrap_directory %>\wget.ps1 (
 <%= win_wget_ps %>
)

:install
@rem Install Chef using chef-client MSI installer

<% url="http://reposerver.example.com/chef-client-11.6.0.rc.1-1.windows.msi" -%>
@set "REMOTE_SOURCE_MSI_URL=<%= url %>"
@set "LOCAL_DESTINATION_MSI_PATH=<%= local_download_path %>"

@powershell -ExecutionPolicy Unrestricted -NoProfile -NonInteractive "& '<%= bootstrap_directory %>\wget.ps1' '%REMOTE_SOURCE_MSI_URL%' '%LOCAL_DESTINATION_MSI_PATH%'"

@REM Replace install_chef from knife-windows Gem with one that has extra flags to turn on Chef service feature -- only available in Chef >= 11.6.x
@REM <%= install_chef %>
@echo Installing Chef Client 11.6.0.rc1 with msiexec
@msiexec /q /i "%LOCAL_DESTINATION_MSI_PATH%" ADDLOCAL="ChefClientFeature,ChefServiceFeature"
@endlocal

@echo Writing validation key...

> <%= bootstrap_directory %>\validation.pem (
 <%= validation_key %>
)

@echo Validation key written.

<% if @config[:encrypted_data_bag_secret] -%>
> <%= bootstrap_directory %>\encrypted_data_bag_secret (
 <%= encrypted_data_bag_secret %>
)
<% end -%>

> <%= bootstrap_directory %>\client.rb (
 <%= config_content %>
)

> <%= bootstrap_directory %>\first-boot.json (
 <%= run_list %>
)

<%= start_chef %>

Examples

The following examples show how to use this knife subcommand:

Bootstrap a node

$ knife bootstrap 12.34.56.789 -P vanilla -x root -r 'recipe[apt],recipe[xfs],recipe[vim]'

which shows something similar to:

...
12.34.56.789 Chef Client finished, 12/12 resources updated in 78.942455583 seconds

Use knife node show to verify:

$ knife node show debian-wheezy.int.domain.org

which returns something similar to:

Node Name:   debian-wheezy.int.domain.org
Environment: _default
FQDN:        debian-wheezy.int.domain.org
IP:          12.34.56.789
Run List:    recipe[apt], recipe[xfs], recipe[vim]
Roles:
Recipes:     apt, xfs, vim, apt::default, xfs::default, vim::default
Platform:    debian 7.4
Tags:

Use an SSH password

$ knife bootstrap 192.168.1.1 -x username -P PASSWORD --sudo

Use a file that contains a private key

$ knife bootstrap 192.168.1.1 -x username -i ~/.ssh/id_rsa --sudo