mount resource¶
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 Chef Infra 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
, andusername
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 a Chef Infra 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
andpassword
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 toremount: 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 Chef Infra 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 anotifies
statement for each resource to be notified.
A timer specifies the point during a Chef Infra 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 a Chef Infra 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 a Chef Infra 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 a Chef Infra 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 a Chef Infra Client run. Based on the results of this evaluation, a guard property is then used to tell Chef Infra 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 returntrue
in addition to0
. - A block is executed as Ruby code that must return either
true
orfalse
. If the block returnstrue
, the guard property is applied. If the block returnsfalse
, 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 Chef Infra Client to do nothing.
Properties
The following properties can be used to define a guard that is evaluated during the execution phase of a Chef Infra 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