cookbook_file

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Use the cookbook_file resource to transfer files from a sub-directory of COOKBOOK_NAME/files/ to a specified path located on a host that is running the chef-client. The file is selected according to file specificity, which allows different source files to be used based on the hostname, host platform (operating system, distro, or as appropriate), or platform version. Files that are located in the COOKBOOK_NAME/files/default sub-directory may be used on any platform.

During a chef-client run, the checksum for each local file is calculated and then compared against the checksum for the same file as it currently exists in the cookbook on the Chef server. A file is not transferred when the checksums match. Only files that require an update are transferred from the Chef server to a node.

Syntax

A cookbook_file resource block manages files by using files that exist within a cookbook’s /files directory. For example, to write the home page for an Apache website:

cookbook_file '/var/www/customers/public_html/index.php' do
  source 'index.php'
  owner 'web_admin'
  group 'web_admin'
  mode '0755'
  action :create
end

where

  • '/var/www/customers/public_html/index.php' is path to the file to be created
  • 'index.php' is a file in the /files directory in a cookbook that is used to create that file (the contents of the file in the cookbook will become the contents of the file on the node)
  • owner, group, and mode define the permissions

The full syntax for all of the properties that are available to the cookbook_file resource is:

cookbook_file 'name' do
  atomic_update              TrueClass, FalseClass
  backup                     FalseClass, Integer
  cookbook                   String
  force_unlink               TrueClass, FalseClass
  group                      String, Integer
  inherits                   TrueClass, FalseClass
  manage_symlink_source      TrueClass, FalseClass, NilClass
  mode                       String, Integer
  notifies                   # see description
  owner                      String, Integer
  path                       String # defaults to 'name' if not specified
  provider                   Chef::Provider::CookbookFile
  rights                     Hash
  source                     String, Array
  subscribes                 # see description
  verify                     String, Block
  action                     Symbol # defaults to :create if not specified
end

where

  • cookbook_file is the resource
  • name is the name of the resource block
  • action identifies the steps the chef-client will take to bring the node into the desired state
  • atomic_update, backup, cookbook, force_unlink, group, inherits, manage_symlink_source, mode, owner, path, provider, rights, source, and verify are properties of this resource, with the Ruby type shown. See “Properties” section below for more information about all of the properties that may be used with this resource.

Actions

This resource has the following actions:

:create
Default. Create a file. If a file already exists (but does not match), update that file to match.
:create_if_missing
Create a file only if the file does not exist. When the file exists, nothing happens.
:delete
Delete a file.
:nothing
Define this resource block to do nothing until notified by another resource to take action. When this resource is notified, this resource block is either run immediately or it is queued up to be run at the end of the chef-client run.
:touch
Touch a file. This updates the access (atime) and file modification (mtime) times for a file. (This action may be used with this resource, but is typically only used with the file resource.)

Properties

This resource has the following properties:

atomic_update

Ruby Types: TrueClass, FalseClass

Perform atomic file updates on a per-resource basis. Set to true for atomic file updates. Set to false for non-atomic file updates. This setting overrides file_atomic_update, which is a global setting found in the client.rb file. Default value: true.

backup

Ruby Types: FalseClass, Integer

The number of backups to be kept in /var/chef/backup (for UNIX- and Linux-based platforms) or C:/chef/backup (for the Microsoft Windows platform). Set to false to prevent backups from being kept. Default value: 5.

cookbook

Ruby Type: String

The cookbook in which a file is located (if it is not located in the current cookbook). The default value is the current cookbook.

force_unlink

Ruby Types: TrueClass, FalseClass

How the chef-client handles certain situations when the target file turns out not to be a file. For example, when a target file is actually a symlink. Set to true for the chef-client delete the non-file target and replace it with the specified file. Set to false for the chef-client to raise an error. Default value: false.

group

Ruby Types: Integer, String

A string or ID that identifies the group owner by group name, including fully qualified group names such as domain\group or group@domain. If this value is not specified, existing groups remain unchanged and new group assignments use the default POSIX group (if available).

ignore_failure

Ruby Types: TrueClass, FalseClass

Continue running a recipe if a resource fails for any reason. Default value: false.

inherits

Ruby Types: TrueClass, FalseClass

Microsoft Windows only. Whether a file inherits rights from its parent directory. Default value: true.

manage_symlink_source

Ruby Types: TrueClass, FalseClass, NilClass

Cause the chef-client to detect and manage the source file for a symlink. Possible values: nil, true, or false. When this value is set to nil, the chef-client will manage a symlink’s source file and emit a warning. When this value is set to true, the chef-client will manage a symlink’s source file and not emit a warning. Default value: nil. The default value will be changed to false in a future version.

mode

Ruby Types: Integer, String

If mode is not specified and if the file already exists, the existing mode on the file is used. If mode is not specified, the file does not exist, and the :create action is specified, the chef-client assumes a mask value of '0777' and then applies the umask for the system on which the file is to be created to the mask value. For example, if the umask on a system is '022', the chef-client uses the default value of '0755'.

The behavior is different depending on the platform.

UNIX- and Linux-based systems: A quoted 3-5 character string that defines the octal mode that is passed to chmod. For example: '755', '0755', or 00755. If the value is specified as a quoted string, it works exactly as if the chmod command was passed. If the value is specified as an integer, prepend a zero (0) to the value to ensure that it is interpreted as an octal number. For example, to assign read, write, and execute rights for all users, use '0777' or '777'; for the same rights, plus the sticky bit, use 01777 or '1777'.

Microsoft Windows: A quoted 3-5 character string that defines the octal mode that is translated into rights for Microsoft Windows security. For example: '755', '0755', or 00755. Values up to '0777' are allowed (no sticky bits) and mean the same in Microsoft Windows as they do in UNIX, where 4 equals GENERIC_READ, 2 equals GENERIC_WRITE, and 1 equals GENERIC_EXECUTE. This property cannot be used to set :full_control. This property has no effect if not specified, but when it and rights are both specified, the effects are cumulative.

notifies

Ruby Type: Symbol, ‘Chef::Resource[String]’

A resource may notify another resource to take action when its state changes. Specify a 'resource[name]', the :action that resource should take, and then the :timer for that action. A resource may notifiy more than one resource; use a notifies statement for each resource to be notified.

A timer specifies the point during the chef-client run at which a notification is run. The following timers are available:

:before
Specifies that the action on a notified resource should be run before processing the resource block in which the notification is located.
:delayed
Default. Specifies that a notification should be queued up, and then executed at the very end of the chef-client run.
:immediate, :immediately
Specifies that a notification should be run immediately, per resource notified.

The syntax for notifies is:

notifies :action, 'resource[name]', :timer
owner

Ruby Types: Integer, String

A string or ID that identifies the group owner by user name, including fully qualified user names such as domain\user or user@domain. If this value is not specified, existing owners remain unchanged and new owner assignments use the current user (when necessary).

path

Ruby Type: String

The path to the destination at which a file is to be created. Default value: the name of the resource block For example: file.txt.

Microsoft Windows: A path that begins with a forward slash (/) will point to the root of the current working directory of the chef-client process. This path can vary from system to system. Therefore, using a path that begins with a forward slash (/) is not recommended.

provider

Ruby Type: Chef Class

Optional. Explicitly specifies a provider.

retries

Ruby Type: Integer

The number of times to catch exceptions and retry the resource. Default value: 0.

retry_delay

Ruby Type: Integer

The retry delay (in seconds). Default value: 2.

rights

Ruby Types: Integer, String

Microsoft Windows only. The permissions for users and groups in a Microsoft Windows environment. For example: rights <permissions>, <principal>, <options> where <permissions> specifies the rights granted to the principal, <principal> is the group or user name, and <options> is a Hash with one (or more) advanced rights options.

source

Ruby Types: String, Array

The name of the file in COOKBOOK_NAME/files/default or the path to a file located in COOKBOOK_NAME/files. The path must include the file name and its extension. Can be used to distribute specific files to specific platforms. See “File Specificity” below for more information. See “Syntax” section above for more information.

subscribes

Ruby Type: Symbol, ‘Chef::Resource[String]’

A resource may listen to another resource, and then take action if the state of the resource being listened to changes. Specify a 'resource[name]', the :action to be taken, and then the :timer for that action.

A timer specifies the point during the chef-client run at which a notification is run. The following timers are available:

:before
Specifies that the action on a notified resource should be run before processing the resource block in which the notification is located.
:delayed
Default. Specifies that a notification should be queued up, and then executed at the very end of the chef-client run.
:immediate, :immediately
Specifies that a notification should be run immediately, per resource notified.

The syntax for subscribes is:

subscribes :action, 'resource[name]', :timer
verify

Ruby Types: String, Block

A block or a string that returns true or false. A string, when true is executed as a system command.

A block is arbitrary Ruby defined within the resource block by using the verify property. When a block is true, the chef-client will continue to update the file as appropriate.

For example, this should return true:

cookbook_file '/tmp/baz' do
  verify { 1 == 1 }
end

This should return true:

cookbook_file '/etc/nginx.conf' do
  verify 'nginx -t -c %{path}'
end

Warning

For releases of the chef-client prior to 12.5 (chef-client 12.4 and earlier) the correct syntax is:

cookbook_file '/etc/nginx.conf' do
  verify 'nginx -t -c %{file}'
end

See GitHub issues https://github.com/chef/chef/issues/3232 and https://github.com/chef/chef/pull/3693 for more information about these differences.

This should return true:

cookbook_file '/tmp/bar' do
  verify { 1 == 1}
end

And this should return true:

cookbook_file '/tmp/foo' do
  verify do |path|
    true
  end
end

Whereas, this should return false:

cookbook_file '/tmp/turtle' do
  verify '/usr/bin/false'
end

If a string or a block return false, the chef-client run will stop and an error is returned.

Note

Use the owner and right properties and avoid the group and mode properties whenever possible. The group and mode properties are not true Microsoft Windows concepts and are provided more for backward compatibility than for best practice.

Warning

For a machine on which SELinux is enabled, the chef-client will create files that correctly match the default policy settings only when the cookbook that defines the action also conforms to the same policy.

Atomic File Updates

Atomic updates are used with file-based resources to help ensure that file updates can be made when updating a binary or if disk space runs out.

Atomic updates are enabled by default. They can be managed globally using the file_atomic_update setting in the client.rb file. They can be managed on a per-resource basis using the atomic_update property that is available with the cookbook_file, file, remote_file, and template resources.

Note

On certain platforms, and after a file has been moved into place, the chef-client may modify file permissions to support features specific to those platforms. On platforms with SELinux enabled, the chef-client will fix up the security contexts after a file has been moved into the correct location by running the restorecon command. On the Microsoft Windows platform, the chef-client will create files so that ACL inheritance works as expected.

Windows File Security

To support Microsoft Windows security, the template, file, remote_file, cookbook_file, directory, and remote_directory resources support the use of inheritance and access control lists (ACLs) within recipes.

Access Control Lists (ACLs)

The rights property can be used in a recipe to manage access control lists (ACLs), which allow permissions to be given to multiple users and groups. Use the rights property can be used as many times as necessary; the chef-client will apply them to the file or directory as required. The syntax for the rights property is as follows:

rights permission, principal, option_type => value

where

permission

Use to specify which rights are granted to the principal. The possible values are: :read, :write, read_execute, :modify, and :full_control.

These permissions are cumulative. If :write is specified, then it includes :read. If :full_control is specified, then it includes both :write and :read.

(For those who know the Microsoft Windows API: :read corresponds to GENERIC_READ; :write corresponds to GENERIC_WRITE; :read_execute corresponds to GENERIC_READ and GENERIC_EXECUTE; :modify corresponds to GENERIC_WRITE, GENERIC_READ, GENERIC_EXECUTE, and DELETE; :full_control corresponds to GENERIC_ALL, which allows a user to change the owner and other metadata about a file.)

principal
Use to specify a group or user name. This is identical to what is entered in the login box for Microsoft Windows, such as user_name, domain\user_name, or user_name@fully_qualified_domain_name. The chef-client does not need to know if a principal is a user or a group.
option_type

A hash that contains advanced rights options. For example, the rights to a directory that only applies to the first level of children might look something like: rights :write, 'domain\group_name', :one_level_deep => true. Possible option types:

Option Type Description
:applies_to_children Specify how permissions are applied to children. Possible values: true to inherit both child directories and files; false to not inherit any child directories or files; :containers_only to inherit only child directories (and not files); :objects_only to recursively inherit files (and not child directories).
:applies_to_self Indicates whether a permission is applied to the parent directory. Possible values: true to apply to the parent directory or file and its children; false to not apply only to child directories and files.
:one_level_deep Indicates the depth to which permissions will be applied. Possible values: true to apply only to the first level of children; false to apply to all children.

For example:

resource 'x.txt' do
  rights :read, 'Everyone'
  rights :write, 'domain\group'
  rights :full_control, 'group_name_or_user_name'
  rights :full_control, 'user_name', :applies_to_children => true
end

or:

rights :read, ['Administrators','Everyone']
rights :full_control, 'Users', :applies_to_children => true
rights :write, 'Sally', :applies_to_children => :containers_only, :applies_to_self => false, :one_level_deep => true

Some other important things to know when using the rights attribute:

  • Only inherited rights remain. All existing explicit rights on the object are removed and replaced.
  • If rights are not specified, nothing will be changed. The chef-client does not clear out the rights on a file or directory if rights are not specified.
  • Changing inherited rights can be expensive. Microsoft Windows will propagate rights to all children recursively due to inheritance. This is a normal aspect of Microsoft Windows, so consider the frequency with which this type of action is necessary and take steps to control this type of action if performance is the primary consideration.

Use the deny_rights property to deny specific rights to specific users. The ordering is independent of using the rights property. For example, it doesn’t matter if rights are granted to everyone is placed before or after deny_rights :read, ['Julian', 'Lewis'], both Julian and Lewis will be unable to read the document. For example:

resource 'x.txt' do
  rights :read, 'Everyone'
  rights :write, 'domain\group'
  rights :full_control, 'group_name_or_user_name'
  rights :full_control, 'user_name', :applies_to_children => true
  deny_rights :read, ['Julian', 'Lewis']
end

or:

deny_rights :full_control, ['Sally']

Inheritance

By default, a file or directory inherits rights from its parent directory. Most of the time this is the preferred behavior, but sometimes it may be necessary to take steps to more specifically control rights. The inherits property can be used to specifically tell the chef-client to apply (or not apply) inherited rights from its parent directory.

For example, the following example specifies the rights for a directory:

directory 'C:\mordor' do
  rights :read, 'MORDOR\Minions'
  rights :full_control, 'MORDOR\Sauron'
end

and then the following example specifies how to use inheritance to deny access to the child directory:

directory 'C:\mordor\mount_doom' do
  rights :full_control, 'MORDOR\Sauron'
  inherits false # Sauron is the only person who should have any sort of access
end

If the deny_rights permission were to be used instead, something could slip through unless all users and groups were denied.

Another example also shows how to specify rights for a directory:

directory 'C:\mordor' do
  rights :read, 'MORDOR\Minions'
  rights :full_control, 'MORDOR\Sauron'
  rights :write, 'SHIRE\Frodo' # Who put that there I didn't put that there
end

but then not use the inherits property to deny those rights on a child directory:

directory 'C:\mordor\mount_doom' do
  deny_rights :read, 'MORDOR\Minions' # Oops, not specific enough
end

Because the inherits property is not specified, the chef-client will default it to true, which will ensure that security settings for existing files remain unchanged.

File Specificity

A cookbook is frequently designed to work across many platforms and is often required to distribute a specific file to a specific platform. A cookbook can be designed to support the distribution of files across platforms, while ensuring that the correct file ends up on each system.

The pattern for file specificity depends on two things: the lookup path and the source attribute. The first pattern that matches is used:

  1. /host-$fqdn/$source
  2. /$platform-$platform_version/$source
  3. /$platform/$source
  4. /default/$source
  5. /$source

Use an array with the source attribute to define an explicit lookup path. For example:

file '/conf.py' do
  source ['#{node.chef_environment}.py', 'conf.py']
end

The following example emulates the entire file specificity pattern by defining it as an explicit path:

file '/conf.py' do
  source %W{
    host-#{node['fqdn']}/conf.py
    #{node['platform']}-#{node['platform_version']}/conf.py
    #{node['platform']}/conf.py
    default/conf.py
  }
end

A cookbook may have a /files directory structure like this:

files/
   host-foo.example.com
   ubuntu-10.04
   ubuntu-10
   ubuntu
   redhat-5.8
   redhat-6.4
   ...
   default

and a resource that looks something like the following:

cookbook_file '/usr/local/bin/apache2_module_conf_generate.pl' do
  source 'apache2_module_conf_generate.pl'
  mode '0755'
  owner 'root'
  group 'root'
end

This resource is matched in the same order as the /files directory structure. For a node that is running Ubuntu 10.04, the second item would be the matching item and the location to which the file identified in the cookbook_file resource would be distributed:

host-foo.example.com/apache2_module_conf_generate.pl
ubuntu-10.04/apache2_module_conf_generate.pl
ubuntu-10/apache2_module_conf_generate.pl
ubuntu/apache2_module_conf_generate.pl
default/apache2_module_conf_generate.pl

If the apache2_module_conf_generate.pl file was located in the cookbook directory under files/host-foo.example.com/, the specified file(s) would only be copied to the machine with the domain name foo.example.com.

Host Notation

The naming of folders within cookbook directories must literally match the host notation used for file specificity matching. For example, if a host is named foo.example.com, the folder must be named host-foo.example.com.

Examples

The following examples demonstrate various approaches for using resources in recipes. If you want to see examples of how Chef uses resources in recipes, take a closer look at the cookbooks that Chef authors and maintains: https://github.com/chef-cookbooks.

Transfer a file

cookbook_file 'file.txt' do
  mode '0755'
end

Handle cookbook_file and yum_package resources in the same recipe

When a cookbook_file resource and a yum_package resource are both called from within the same recipe, use the flush_cache attribute to dump the in-memory Yum cache, and then use the repository immediately to ensure that the correct package is installed:

cookbook_file '/etc/yum.repos.d/custom.repo' do
  source 'custom'
  mode '0755'
end

yum_package 'only-in-custom-repo' do
  action :install
  flush_cache [ :before ]
end

Install repositories from a file, trigger a command, and force the internal cache to reload

The following example shows how to install new Yum repositories from a file, where the installation of the repository triggers a creation of the Yum cache that forces the internal cache for the chef-client to reload:

execute 'create-yum-cache' do
 command 'yum -q makecache'
 action :nothing
end

ruby_block 'reload-internal-yum-cache' do
  block do
    Chef::Provider::Package::Yum::YumCache.instance.reload
  end
  action :nothing
end

cookbook_file '/etc/yum.repos.d/custom.repo' do
  source 'custom'
  mode '0755'
  notifies :run, 'execute[create-yum-cache]', :immediately
  notifies :create, 'ruby_block[reload-internal-yum-cache]', :immediately
end

Use a case statement

The following example shows how a case statement can be used to handle a situation where an application needs to be installed on multiple platforms, but where the install directories are different paths, depending on the platform:

cookbook_file 'application.pm' do
  path case node['platform']
    when 'centos','redhat'
      '/usr/lib/version/1.2.3/dir/application.pm'
    when 'arch'
      '/usr/share/version/core_version/dir/application.pm'
    else
      '/etc/version/dir/application.pm'
    end
  source "application-#{node['languages']['perl']['version']}.pm"
  owner 'root'
  group 'root'
  mode '0755'
end

Manage dotfiles

The following example shows using the directory and cookbook_file resources to manage dotfiles. The dotfiles are defined by a JSON data structure similar to:

"files": {
  ".zshrc": {
    "mode": '0755',
    "source": "dot-zshrc"
    },
  ".bashrc": {
    "mode": '0755',
    "source": "dot-bashrc"
     },
  ".bash_profile": {
    "mode": '0755',
    "source": "dot-bash_profile"
    },
  }

and then the following resources manage the dotfiles:

if u.has_key?('files')
  u['files'].each do |filename, file_data|

  directory "#{home_dir}/#{File.dirname(filename)}" do
    recursive true
    mode '0755'
  end if file_data['subdir']

  cookbook_file "#{home_dir}/#{filename}" do
    source "#{u['id']}/#{file_data['source']}"
    owner 'u['id']'
    group 'group_id'
    mode 'file_data['mode']'
    ignore_failure true
    backup 0
  end
end