file
Use the file resource to manage files directly on a node.
Note
Use the cookbook_file resource to copy a file from a cookbook’s /files
directory. Use the template resource to create a file based on a template in a cookbook’s /templates
directory. And use the remote_file resource to transfer a file to a node from a remote location.
Syntax
A file resource block manages files that exist on nodes. For example, to write the home page for an Apache website:
file '/var/www/customers/public_html/index.php' do content '<html>This is a placeholder for the home page.</html>' mode '0755' owner 'web_admin' group 'web_admin' end
where
-
'/var/www/customers/public_html/index.php'
is path to the file and also the filename to be managed -
content
defines the contents of the file
The full syntax for all of the properties that are available to the file resource is:
file 'name' do atomic_update TrueClass, FalseClass backup FalseClass, Integer checksum String content 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::File rights Hash sensitive TrueClass, FalseClass subscribes # see description action Symbol # defaults to :create if not specified end
where
-
file
is the resource -
name
is the name of the resource block; when thepath
property is not specified as part of a recipe,name
is also the path to the file -
content
specifies the contents of the file -
:action
identifies the steps the chef-client will take to bring the node into the desired state -
atomic_update
,backup
,checksum
,content
,force_unlink
,group
,inherits
,manage_symlink_source
,mode
,owner
,path
,provider
,rights
, andsensitive
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.
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.
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 tofalse
for non-atomic file updates. This setting overridesfile_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) orC:/chef/backup
(for the Microsoft Windows platform). Set tofalse
to prevent backups from being kept. Default value:5
. checksum
-
Ruby Types: String
The SHA-256 checksum of the file. Use to ensure that a specific file is used. If the checksum does not match, the file is not used. Default value: no checksum required.
content
-
Ruby Type: String
A string that is written to the file. The contents of this property replace any previous content when this property has something other than the default value. The default behavior will not modify content.
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 tofalse
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
orgroup@domain
. If this value is not specified, existing groups remain unchanged and new group assignments use the defaultPOSIX
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
, orfalse
. When this value is set tonil
, the chef-client will manage a symlink’s source file and emit a warning. When this value is set totrue
, the chef-client will manage a symlink’s source file and not emit a warning. Default value:nil
. The default value will be changed tofalse
in a future version. mode
-
Ruby Types: Integer, String
A quoted 3-5 character string that defines the octal mode. For example:
'755'
,'0755'
, or00755
. Ifmode
is not specified and if the file already exists, the existing mode on the file is used. Ifmode
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 themask
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'
, or00755
. If the value is specified as a quoted string, it works exactly as if thechmod
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, use01777
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'
, or00755
. Values up to'0777'
are allowed (no sticky bits) and mean the same in Microsoft Windows as they do in UNIX, where4
equalsGENERIC_READ
,2
equalsGENERIC_WRITE
, and1
equalsGENERIC_EXECUTE
. This property cannot be used to set:full_control
. This property has no effect if not specified, but when it andrights
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 anotifies
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:
: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
oruser@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 full path to the file, including the file name and its extension. For example:
/files/file.txt
. Default value: thename
of the resource block See “Syntax” section above for more information.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. sensitive
-
Ruby Types: TrueClass, FalseClass
Ensure that sensitive resource data is not logged by the chef-client. Default value:
false
. 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:
: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
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 toGENERIC_READ
;:write
corresponds toGENERIC_WRITE
;:read_execute
corresponds toGENERIC_READ
andGENERIC_EXECUTE
;:modify
corresponds toGENERIC_WRITE
,GENERIC_READ
,GENERIC_EXECUTE
, andDELETE
;:full_control
corresponds toGENERIC_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
, oruser_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.
Providers
Where a resource represents a piece of the system (and its desired state), a provider defines the steps that are needed to bring that piece of the system from its current state into the desired state.
The chef-client will determine the correct provider based on configuration data collected by Ohai at the start of the chef-client run. This configuration data is then mapped to a platform and an associated list of providers.
Generally, it’s best to let the chef-client choose the provider, and this is (by far) the most common approach. However, in some cases, specifying a provider may be desirable. There are two approaches:
- Use a more specific short name—
yum_package "foo" do
instead ofpackage "foo" do
,script "foo" do
instead ofbash "foo" do
, and so on—when available - Use the
provider
property within the resource block to specify the long name of the provider as a property of a resource. For example:provider Chef::Provider::Long::Name
This resource has the following providers:
-
Chef::Provider::File
,file
- The default provider for all platforms.
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.
Create a file
file '/tmp/something' do owner 'root' group 'root' mode '0755' action :create end
Create a file in Microsoft Windows
To create a file in Microsoft Windows, be sure to add an escape character—\
—before the backslashes in the paths:
file 'C:\\tmp\\something.txt' do rights :read, 'Everyone' rights :full_control, 'DOMAIN\\User' action :create end
Remove a file
file '/tmp/something' do action :delete end
Set file modes
file '/tmp/something' do mode '0755' end
Delete a repository using yum to scrub the cache
# the following code sample thanks to gaffneyc @ https://gist.github.com/918711 execute 'clean-yum-cache' do command 'yum clean all' action :nothing end file '/etc/yum.repos.d/bad.repo' do action :delete notifies :run, 'execute[clean-yum-cache]', :immediately notifies :create, 'ruby_block[reload-internal-yum-cache]', :immediately end
Add the value of a data bag item to a file
The following example shows how to get the contents of a data bag item named impossible_things
, create a .pem file located at some/directory/path/
, and then use the content
attribute to update the contents of that file with the value of the impossible_things
data bag item:
private_key = data_bag_item('impossible_things', private_key_name)['private_key'] file "some/directory/path/#{private_key_name}.pem" do content private_key owner 'root' group 'group' mode '0755' end
Write a YAML file
The following example shows how to use the content
property to write a YAML file:
file "#{app['deploy_to']}/shared/config/settings.yml" do owner "app['owner']" group "app['group']" mode '0755' content app.to_yaml end
Write a string to a file
The following example specifies a directory, and then uses the content
property to add a string to the file created in that directory:
status_file = '/path/to/file/status_file' file status_file do owner 'root' group 'root' mode '0755' content 'My favourite foremost coastal Antarctic shelf, oh Larsen B!' end
Create a file from a copy
The following example shows how to copy a file from one directory to another, locally on a node:
file '/root/1.txt' do content IO.read('/tmp/1.txt') action :create end
where the content
attribute uses the Ruby IO.read
method to get the contents of the /tmp/1.txt
file.
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https://docs-archive.chef.io/release/11-18/resource_file.html