ifconfig resource

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Use the ifconfig resource to manage interfaces on Unix and Linux systems.

Syntax

An ifconfig resource block manages interfaces, such as a static IP address:

ifconfig '33.33.33.80' do
  device 'eth1'
end

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

ifconfig 'name' do
  bcast             String
  bonding_opts      String
  bootproto         String
  device            String
  ethtool_opts      String
  family            String # default value: "inet"
  gateway           String
  hwaddr            String
  inet_addr         String
  mask              String
  master            String
  metric            String
  mtu               String
  network           String
  onboot            String
  onparent          String
  slave             String
  target            String # default value: 'name' unless specified
  vlan              String
  action            Symbol # defaults to :add if not specified
end

where:

  • ifconfig 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.
  • bcast, bonding_opts, bootproto, device, ethtool_opts, family, gateway, hwaddr, inet_addr, mask, master, metric, mtu, network, onboot, onparent, slave, target, and vlan are the properties available to this resource.

Actions

The ifconfig resource has the following actions:

:add
Default. Run ifconfig to configure a network interface and (on some platforms) write a configuration file for that network interface.
:delete
Run ifconfig to disable a network interface and (on some platforms) delete that network interface’s configuration file.
:disable
Run ifconfig to disable a network interface.
:enable
Run ifconfig to enable a network interface.
: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.

Properties

The ifconfig resource has the following properties:

bcast

Ruby Type: String

The broadcast address for a network interface. On some platforms this property is not set using ifconfig, but instead is added to the startup configuration file for the network interface.

bonding_opts

Ruby Type: String

Bonding options to pass via BONDING_OPTS on RHEL and CentOS. For example: mode=active-backup miimon=100

New in Chef Client 13.4.

bootproto

Ruby Type: String

The boot protocol used by a network interface.

device

Ruby Type: String

The network interface to be configured.

ethtool_opts

Ruby Type: String

Options to be passed to ethtool(8). For example: -A eth0 autoneg off rx off tx off

New in Chef Client 13.4.

family

Ruby Type: String | Default Value: "inet"

Networking family option for Debian-based systems; for example: inet or inet6.

New in Chef Client 14.0.

gateway

Ruby Type: String

The gateway to use for the interface.

New in Chef Client 14.4.

hwaddr

Ruby Type: String

The hardware address for the network interface.

inet_addr

Ruby Type: String

The Internet host address for the network interface.

mask

Ruby Type: String

The decimal representation of the network mask. For example: 255.255.255.0.

master

Ruby Type: String

Specifies the channel bonding interface to which the Ethernet interface is linked.

New in Chef Client 13.4.

metric

Ruby Type: String

The routing metric for the interface.

mtu

Ruby Type: String

The maximum transmission unit (MTU) for the network interface.

network

Ruby Type: String

The address for the network interface.

onboot

Ruby Type: String

Bring up the network interface on boot.

onparent

Ruby Type: String

Bring up the network interface when its parent interface is brought up.

slave

Ruby Type: String

When set to yes, this device is controlled by the channel bonding interface that is specified via the master property.

New in Chef Client 13.4.

target

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

The IP address that is to be assigned to the network interface. If not specified we’ll use the resource’s name.

vlan

Ruby Type: String

The VLAN to assign the interface to.

New in Chef Client 14.4.

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:

Configure a network interface

ifconfig "33.33.33.80" do
  bootproto "dhcp"
  device "eth1"
end

will create the following interface:

vagrant@default-ubuntu-1204:~$ cat /etc/network/interfaces.d/ifcfg-eth1
iface eth1 inet dhcp

Specify a boot protocol

ifconfig '192.186.0.1' do
  device 'eth0'
end

Specify a static IP address

ifconfig "33.33.33.80" do
  device "eth1"
end

will create the following interface:

iface eth1 inet static
  address 33.33.33.80

Update a static IP address with a boot protocol

ifconfig "33.33.33.80" do
  bootproto "dhcp"
  device "eth1"
end

will update the interface from static to dhcp:

iface eth1 inet dhcp
  address 33.33.33.80