mount resource

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Use the mount resource to manage a mounted file system.

Syntax

The mount resource has the following syntax:

mount 'name' do
  device           String
  device_type      String, Symbol # default value: :device
  domain           String
  dump             Integer, false # default value: 0
  enabled          true, false # default value: false
  fsck_device      String # default value: "-"
  fstype           String # default value: "auto"
  mount_point      String # default value: 'name' unless specified
  options          Array, String # default value: ["defaults"]
  pass             Integer, false # default value: 2
  password         String
  supports         Array, Hash
  username         String
  action           Symbol # defaults to :mount if not specified
end

where:

  • mount is the resource.
  • name is the name given to the resource block.
  • action identifies which steps the chef-client will take to bring the node into the desired state.
  • device, device_type, domain, dump, enabled, fsck_device, fstype, mount_point, options, pass, password, supports, and username are the properties available to this resource.

Actions

The mount resource has the following actions:

:disable
Remove an entry from the file systems table (fstab).
:enable
Add an entry to the file systems table (fstab).
:mount
Default. Mount a device.
:nothing
This resource block does not act unless notified by another resource to take action. Once notified, this resource block either runs immediately or is queued up to run at the end of the Chef Client run.
:remount
Remount a device.
:umount
Unmount a device.
:unmount
Alias for :umount action.

Note

Order matters when passing multiple actions. For example: action [:mount, :enable] ensures that the file system is mounted before it is enabled.

Properties

The mount resource has the following properties:

device

Ruby Type: String

Required for :umount and :remount actions (for the purpose of checking the mount command output for presence). The special block device or remote node, a label, or a uuid to be mounted.

device_type

Ruby Type: String, Symbol | Default Value: :device

The type of device: :device, :label, or :uuid

domain

Ruby Type: String

Windows only: Use to specify the domain in which the username and password are located.

dump

Ruby Type: Integer, false | Default Value: 0

The dump frequency (in days) used while creating a file systems table (fstab) entry.

enabled

Ruby Type: true, false | Default Value: false

Use to specify if a mounted file system is enabled.

fsck_device

Ruby Type: String | Default Value: "-"

Solaris only: The fsck device.

fstype

Ruby Type: String | Default Value: "auto"

The file system type (fstype) of the device.

mount_point

Ruby Type: String | Default Value: The resource block's name

The directory (or path) in which the device is to be mounted. Defaults to the name of the resource block if not provided.

options

Ruby Type: Array, String | Default Value: ["defaults"]

An array or comma separated list of options for the mount.

pass

Ruby Type: Integer, false | Default Value: 2

The pass number used by the file system check (fsck) command while creating a file systems table (fstab) entry.

password

Ruby Type: String

Windows only. Use to specify the password for username.

supports

Ruby Type: Array, Hash

Specify a Hash of supported mount features. Default value: remount: false (preferred). Array defaults to remount: true (non-preferred).

username

Ruby Type: String

Windows only: Use to specify the user name.

Common Resource Functionality

Chef resources include common properties, notifications, and resource guards.

Common Properties

The following properties are common to every resource:

ignore_failure

Ruby Type: true, false | Default Value: false

Continue running a recipe if a resource fails for any reason.

retries

Ruby Type: Integer | Default Value: 0

The number of attempts to catch exceptions and retry the resource.

retry_delay

Ruby Type: Integer | Default Value: 2

The retry delay (in seconds).

sensitive

Ruby Type: true, false | Default Value: false

Ensure that sensitive resource data is not logged by the chef-client.

Notifications

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 notify 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 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
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.

Note that subscribes does not apply the specified action to the resource that it listens to - for example:

file '/etc/nginx/ssl/example.crt' do
  mode '0600'
  owner 'root'
end

service 'nginx' do
  subscribes :reload, 'file[/etc/nginx/ssl/example.crt]', :immediately
end

In this case the subscribes property reloads the nginx service whenever its certificate file, located under /etc/nginx/ssl/example.crt, is updated. subscribes does not make any changes to the certificate file itself, it merely listens for a change to the file, and executes the :reload action for its resource (in this example nginx) when a change is detected.

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 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

Guards

A guard property can be used to evaluate the state of a node during the execution phase of the chef-client run. Based on the results of this evaluation, a guard property is then used to tell the chef-client if it should continue executing a resource. A guard property accepts either a string value or a Ruby block value:

  • A string is executed as a shell command. If the command returns 0, the guard is applied. If the command returns any other value, then the guard property is not applied. String guards in a powershell_script run Windows PowerShell commands and may return true in addition to 0.
  • A block is executed as Ruby code that must return either true or false. If the block returns true, the guard property is applied. If the block returns false, the guard property is not applied.

A guard property is useful for ensuring that a resource is idempotent by allowing that resource to test for the desired state as it is being executed, and then if the desired state is present, for the chef-client to do nothing.

The following properties can be used to define a guard that is evaluated during the execution phase of the chef-client run:

not_if
Prevent a resource from executing when the condition returns true.
only_if
Allow a resource to execute only if the condition returns true.

Examples

The following examples demonstrate various approaches for using resources in recipes:

Mount a labeled file system

mount '/mnt/volume1' do
  device 'volume1'
  device_type :label
  fstype 'xfs'
  options 'rw'
end

Mount a local block drive

mount '/mnt/local' do
  device '/dev/sdb1'
  fstype 'ext3'
end

Mount a non-block file system

mount '/mount/tmp' do
  pass     0
  fstype   'tmpfs'
  device   '/dev/null'
  options  'nr_inodes=999k,mode=755,size=500m'
  action   [:mount, :enable]
end

Mount and add to the file systems table

mount '/export/www' do
  device 'nas1prod:/export/web_sites'
  fstype 'nfs'
  options 'rw'
  action [:mount, :enable]
end

Mount a remote file system

mount '/export/www' do
  device 'nas1prod:/export/web_sites'
  fstype 'nfs'
  options 'rw'
end

Mount a remote folder in Microsoft Windows

mount 'T:' do
  action :mount
  device '\\\\hostname.example.com\\folder'
end

Unmount a remote folder in Microsoft Windows

mount 'T:' do
  action :umount
  device '\\\\hostname.example.com\\D$'
end

Stop a service, do stuff, and then restart it

The following example shows how to use the execute, service, and mount resources together to ensure that a node running on Amazon EC2 is running MySQL. This example does the following:

  • Checks to see if the Amazon EC2 node has MySQL
  • If the node has MySQL, stops MySQL
  • Installs MySQL
  • Mounts the node
  • Restarts MySQL
# the following code sample comes from the ``server_ec2``
# recipe in the following cookbook:
# https://github.com/chef-cookbooks/mysql

if (node.attribute?('ec2') && ! FileTest.directory?(node['mysql']['ec2_path']))

  service 'mysql' do
    action :stop
  end

  execute 'install-mysql' do
    command "mv #{node['mysql']['data_dir']} #{node['mysql']['ec2_path']}"
    not_if do FileTest.directory?(node['mysql']['ec2_path']) end
  end

  [node['mysql']['ec2_path'], node['mysql']['data_dir']].each do |dir|
    directory dir do
      owner 'mysql'
      group 'mysql'
    end
  end

  mount node['mysql']['data_dir'] do
    device node['mysql']['ec2_path']
    fstype 'none'
    options 'bind,rw'
    action [:mount, :enable]
  end

  service 'mysql' do
    action :start
  end

end

where

  • the two service resources are used to stop, and then restart the MySQL service
  • the execute resource is used to install MySQL
  • the mount resource is used to mount the node and enable MySQL