packer-cn/website/pages/docs/provisioners/chef-client.mdx

---
description: >
  The chef-client Packer 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.
layout: docs
page_title: Chef Client - Provisioners
sidebar_title: Chef Client
---

# Chef Client Provisioner

Type: `chef-client`

The Chef Client Packer provisioner installs and configures software on machines
built by Packer using [chef-client](https://docs.chef.io/chef_client.html).
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 Chef.

## Basic Example

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

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

Note: to properly clean up the Chef node and client the machine on which packer
is running must have knife on the path and configured globally, i.e,
`~/.chef/knife.rb` must be present and configured for the target chef server

## Configuration Reference

The reference of available configuration options is listed below. No
configuration is actually required.

- `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.

- `chef_license` (string) - As of Chef v15, Chef requires users to accept a
  license. Defaults to `accept-silent` when `skip_install` is false and
  `install_command` is unset. Possible values are `accept`,
  `accept-silent` and `accept-no-persist`. For details see [Accepting the
  Chef License](https://docs.chef.io/chef_license_accept.html).

  This is a [template engine](/docs/templates/engine.html). Therefore, you
  may use user variables and template functions in this field.

- `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.

- `elevated_user` and `elevated_password` (string) - If specified, Chef will
  be run with elevated privileges using the given Windows user. See the
  [powershell](/docs/provisioners/powershell) provisioner for the full
  details.

- `encrypted_data_bag_secret_path` (string) - The path to the file containing
  the secret for encrypted data bags. By default, this is empty, so no secret
  will be available.

- `execute_command` (string) - The command used to execute Chef. This has
  various [configuration template variables](/docs/templates/engine)
  available. See below for more information.

- `guest_os_type` (string) - The target guest OS type, either "unix" or
  "windows". Setting this to "windows" will cause the provisioner to use
  Windows friendly paths and commands. By default, this is "unix".

- `install_command` (string) - The command used to install Chef. This has
  various [configuration template variables](/docs/templates/engine)
  available. See below for more information.

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

- `knife_command` (string) - The command used to run Knife during node
  clean-up. This has various [configuration template
  variables](/docs/templates/engine) available. See below for more
  information.

- `node_name` (string) - The name of the node to register with the Chef
  Server. This is optional and by default is `packer-{{uuid}}`.

- `policy_group` (string) - The name of a policy group that exists on the
  Chef server. `policy_name` must also be specified.

- `policy_name` (string) - The name of a policy, as identified by the name
  setting in a `Policyfile.rb` file. `policy_group` must also be specified.

- `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. This has no effect when guest_os_type is
  windows.

- `run_list` (array of strings) - The [run
  list](http://docs.chef.io/essentials_node_object_run_lists) 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.

- `skip_clean_staging_directory` (boolean) - If true, Packer won't remove the
  Chef staging directory from the machine after it is done running. By
  default, this is false.

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

- `ssl_verify_mode` (string) - Set to "verify_none" to skip validation of
  SSL certificates. If not set, this defaults to "verify_peer" which
  validates all SSL certifications.

- `trusted_certs_dir` (string) - This is a directory that contains additional
  SSL certificates to trust. Any certificates in this directory will be added
  to whatever CA bundle ruby is using. Use this to add self-signed certs for
  your Chef Server or local HTTP file servers.

- `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` when guest_os_type unix and
  `$env:TEMP/packer-chef-client` when windows. This directory doesn't need to
  exist but must have proper permissions so that the user that Packer uses is
  able to create directories and write into this folder. By default the
  provisioner will create and chmod 0777 this directory.

- `client_key` (string) - Path to client key. If not set, this defaults to a
  file named client.pem in `staging_directory`.

- `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.

- `version` (string) - The version of Chef to be installed. By default this
  is empty which will install the latest version of Chef.

@include 'provisioners/common-config.mdx'

## 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:

```liquid
log_level        :info
log_location     STDOUT
chef_server_url  "{{.ServerUrl}}"
client_key       "{{.ClientKey}}"
chef_license     "{{.ChefLicense}}"
{{if ne .EncryptedDataBagSecretPath ""}}
encrypted_data_bag_secret "{{.EncryptedDataBagSecretPath}}"
{{end}}
{{if ne .ValidationClientName ""}}
validation_client_name "{{.ValidationClientName}}"
{{else}}
validation_client_name "chef-validator"
{{end}}
{{if ne .ValidationKeyPath ""}}
validation_key "{{.ValidationKeyPath}}"
{{end}}
node_name "{{.NodeName}}"
{{if ne .ChefEnvironment ""}}
environment "{{.ChefEnvironment}}"
{{end}}
{{if ne .PolicyGroup ""}}
policy_group "{{.PolicyGroup}}"
{{end}}
{{if ne .PolicyName ""}}
policy_name "{{.PolicyName}}"
{{end}}
{{if ne .SslVerifyMode ""}}
ssl_verify_mode :{{.SslVerifyMode}}
{{end}}
{{if ne .TrustedCertsDir ""}}
trusted_certs_dir :{{.TrustedCertsDir}}
{{end}}
```

This template is a [configuration template](/docs/templates/engine) and
has a set of variables available to use:

- `ChefEnvironment` - The Chef environment name.
- `ChefLicense` - The Chef license acceptance value.
- `EncryptedDataBagSecretPath` - The path to the secret key file to decrypt
  encrypted data bags.
- `NodeName` - The node name set in the configuration.
- `ServerUrl` - The URL of the Chef Server set in the configuration.
- `SslVerifyMode` - Whether Chef SSL verify mode is on or off.
- `TrustedCertsDir` - Path to dir with trusted certificates.
- `ValidationClientName` - The name of the client used for validation.
- `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:

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

When guest_os_type is set to "windows", Packer uses the following command to
execute Chef. The full path to Chef is required because the PATH environment
variable changes don't immediately propagate to running processes.

```liquid
c:/opscode/chef/bin/chef-client.bat \
  --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.
- `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.

```text
curl -L https://omnitruck.chef.io/chef/install.sh | \
  {{if .Sudo}}sudo{{end}} bash
```

When guest_os_type is set to "windows", Packer uses the following command to
install the latest version of Chef:

```text
powershell.exe -Command "(New-Object System.Net.WebClient).DownloadFile('http://chef.io/chef/install.msi', 'C:\\Windows\\Temp\\chef.msi');Start-Process 'msiexec' -ArgumentList '/qb /i C:\\Windows\\Temp\\chef.msi' -NoNewWindow -Wait"
```

This command can be customized using the `install_command` configuration.

## Knife Command

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

```liquid
{{if .Sudo}}sudo {{end}}knife \
  {{.Args}} \
  {{.Flags}}
```

When guest_os_type is set to "windows", Packer uses the following command to
execute Chef. The full path to Chef is required because the PATH environment
variable changes don't immediately propagate to running processes.

```liquid
c:/opscode/chef/bin/knife.bat \
  {{.Args}} \
  {{.Flags}}
```

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

- `Args` - The command arguments that are getting passed to the Knife
  command.
- `Flags` - The command flags that are getting passed to the Knife command..
- `Sudo` - A boolean of whether to `sudo` the command or not, depending on
  the value of the `prevent_sudo` configuration.

## Folder Permissions

!> The `chef-client` provisioner will chmod the directory with your Chef
keys to 777. This is to ensure that Packer can upload and make use of that
directory. However, once the machine is created, you usually don't want to keep
these directories with those permissions. To change the permissions on the
directories, append a shell provisioner after Chef to modify them.

## Examples

### Chef Client Local Mode - Simple

The following example shows how to run the `chef-client` provisioner in local
mode.

**Packer variables**

Set the necessary Packer variables using environment variables or provide a
[var file](/docs/templates/user-variables).

```json
"variables": {
  "chef_dir": "/tmp/packer-chef-client"
}
```

**Setup the** `chef-client` **provisioner**

Make sure we have the correct directories and permissions for the `chef-client`
provisioner. You will need to bootstrap the Chef run by providing the necessary
cookbooks using Berkshelf or some other means.

```json
  "provisioners": [
    ...
    { "type": "shell", "inline": [ "mkdir -p {{user `chef_dir`}}" ] },
    { "type": "file",  "source": "./roles",        "destination": "{{user `chef_dir`}}" },
    { "type": "file",  "source": "./cookbooks",    "destination": "{{user `chef_dir`}}" },
    { "type": "file",  "source": "./data_bags",    "destination": "{{user `chef_dir`}}" },
    { "type": "file",  "source": "./environments", "destination": "{{user `chef_dir`}}" },
    { "type": "file",  "source": "./scripts/install_chef.sh", "destination": "{{user `chef_dir`}}/install_chef.sh" },
    {
      "type":              "chef-client",
      "install_command":   "sudo bash {{user `chef_dir`}}/install_chef.sh",
      "server_url":        "http://localhost:8889",
      "config_template":   "./config/client.rb.template",
      "run_list":          [ "role[testing]" ],
      "skip_clean_node":   true,
      "skip_clean_client": true
    }
    ...
  ]
```

And ./config/client.rb.template referenced by the above configuration:

```ruby
log_level         :info
log_location      STDOUT
local_mode        true
chef_zero.enabled true
ssl_verify_mode   "verify_peer"
role_path         "{{user `chef_dir`}}/roles"
data_bag_path     "{{user `chef_dir`}}/data_bags"
environment_path  "{{user `chef_dir`}}/environments"
cookbook_path     [ "{{user `chef_dir`}}/cookbooks" ]
```

### Chef Client Local Mode - Passing variables

The following example shows how to run the `chef-client` provisioner in local
mode, while passing a `run_list` using a variable.

**Local environment variables**

    # Machine's Chef directory
    export PACKER_CHEF_DIR=/var/chef-packer
    # Comma separated run_list
    export PACKER_CHEF_RUN_LIST="recipe[apt],recipe[nginx]"

**Packer variables**

Set the necessary Packer variables using environment variables or provide a
[var file](/docs/templates/user-variables).

```json
"variables": {
  "chef_dir": "{{env `PACKER_CHEF_DIR`}}",
  "chef_run_list": "{{env `PACKER_CHEF_RUN_LIST`}}",
  "chef_client_config_tpl": "{{env `PACKER_CHEF_CLIENT_CONFIG_TPL`}}",
  "packer_chef_bootstrap_dir": "{{env `PACKER_CHEF_BOOTSTRAP_DIR`}}" ,
  "packer_uid": "{{env `PACKER_UID`}}",
  "packer_gid": "{{env `PACKER_GID`}}"
}
```

**Setup the** `chef-client` **provisioner**

Make sure we have the correct directories and permissions for the `chef-client`
provisioner. You will need to bootstrap the Chef run by providing the necessary
cookbooks using Berkshelf or some other means.

```json
({
  "type": "file",
  "source": "{{user `packer_chef_bootstrap_dir`}}",
  "destination": "/tmp/bootstrap"
},
{
  "type": "shell",
  "inline": [
    "sudo mkdir -p {{user `chef_dir`}}",
    "sudo mkdir -p /tmp/packer-chef-client",
    "sudo chown {{user `packer_uid`}}.{{user `packer_gid`}} /tmp/packer-chef-client",
    "sudo sh /tmp/bootstrap/bootstrap.sh"
  ]
},
{
  "type": "chef-client",
  "server_url": "http://localhost:8889",
  "config_template": "{{user `chef_client_config_tpl`}}/client.rb.tpl",
  "skip_clean_node": true,
  "skip_clean_client": true,
  "run_list": "{{user `chef_run_list`}}"
})
```