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docs Chef-Client Provisioner

Chef Client Provisioner

Type: chef-client

The Chef Client provisioner installs and configures software on machines built by Packer using chef-client. Packer configures a Chef client to talk to a remote Chef Server to provision the machine.

The provisioner will even install Chef onto your machine if it isn't already installed, using the official Chef installers provided by Opscode.

Basic Example

The example below is fully functional. It will install Chef onto the remote machine and run Chef client.

{
  "type": "chef-client",
  "server_url": "https://mychefserver.com/"
}

Note: to properly clean up the Chef node and client, you must have knife on your path and properly configured.

Configuration Reference

The reference of available configuration options is listed below. No configuration is actually required, but node_name is recommended since it will allow the provisioner to clean up the node/client.

  • chef_environment (string) - The name of the chef_environment sent to the Chef server. By default this is empty and will not use an environment.

  • config_template (string) - Path to a template that will be used for the Chef configuration file. By default Packer only sets configuration it needs to match the settings set in the provisioner configuration. If you need to set configurations that the Packer provisioner doesn't support, then you should use a custom configuration template. See the dedicated "Chef Configuration" section below for more details.

  • execute_command (string) - The command used to execute Chef. This has various configuration template variables available. See below for more information.

  • install_command (string) - The command used to install Chef. This has various configuration template variables available. See below for more information.

  • json (object) - An arbitrary mapping of JSON that will be available as node attributes while running Chef.

  • node_name (string) - The name of the node to register with the Chef Server. This is optional and by defalt is empty. If you don't set this, Packer can't clean up the node from the Chef Server using knife.

  • prevent_sudo (boolean) - By default, the configured commands that are executed to install and run Chef are executed with sudo. If this is true, then the sudo will be omitted.

  • run_list (array of strings) - The run list for Chef. By default this is empty, and will use the run list sent down by the Chef Server.

  • server_url (string) - The URL to the Chef server. This is required.

  • skip_clean_client (boolean) - If true, Packer won't remove the client from the Chef server after it is done running. By default, this is false.

  • skip_clean_node (boolean) - If true, Packer won't remove the node from the Chef server after it is done running. By default, this is false. This will be true by default if node_name is not set.

  • skip_install (boolean) - If true, Chef will not automatically be installed on the machine using the Opscode omnibus installers.

  • staging_directory (string) - This is the directory where all the configuration of Chef by Packer will be placed. By default this is "/tmp/packer-chef-client". This directory doesn't need to exist but must have proper permissions so that the SSH user that Packer uses is able to create directories and write into this folder. If the permissions are not correct, use a shell provisioner prior to this to configure it properly.

  • validation_client_name (string) - Name of the validation client. If not set, this won't be set in the configuration and the default that Chef uses will be used.

  • validation_key_path (string) - Path to the validation key for communicating with the Chef Server. This will be uploaded to the remote machine. If this is NOT set, then it is your responsibility via other means (shell provisioner, etc.) to get a validation key to where Chef expects it.

Chef Configuration

By default, Packer uses a simple Chef configuration file in order to set the options specified for the provisioner. But Chef is a complex tool that supports many configuration options. Packer allows you to specify a custom configuration template if you'd like to set custom configurations.

The default value for the configuration template is:

log_level        :info
log_location     STDOUT
chef_server_url  "{{.ServerUrl}}"
validation_client_name "chef-validator"
{{if ne .ValidationKeyPath ""}}
validation_key "{{.ValidationKeyPath}}"
{{end}}
{{if ne .NodeName ""}}
node_name "{{.NodeName}}"
{{end}}

This template is a configuration template and has a set of variables available to use:

  • NodeName - The node name set in the configuration.
  • ServerUrl - The URL of the Chef Server set in the configuration.
  • ValidationKeyPath - Path to the validation key, if it is set.

Execute Command

By default, Packer uses the following command (broken across multiple lines for readability) to execute Chef:

{{if .Sudo}}sudo {{end}}chef-client \
  --no-color \
  -c {{.ConfigPath}} \
  -j {{.JsonPath}}

This command can be customized using the execute_command configuration. As you can see from the default value above, the value of this configuration can contain various template variables, defined below:

  • ConfigPath - The path to the Chef configuration file. file.
  • JsonPath - The path to the JSON attributes file for the node.
  • Sudo - A boolean of whether to sudo the command or not, depending on the value of the prevent_sudo configuration.

Install Command

By default, Packer uses the following command (broken across multiple lines for readability) to install Chef. This command can be customized if you want to install Chef in another way.

curl -L https://www.opscode.com/chef/install.sh | \
  {{if .Sudo}}sudo{{end}} bash

This command can be customized using the install_command configuration.