CfnInstance

The instance type, such as `t2.micro` . For a list of supported instance types, open the stack in the console, choose *Instances* , and choose *+ Instance* . The *Size* list contains the currently supported types. For more information, see [Instance Families and Types](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html) . The parameter values that you use to specify the various types are in the *API Name* column of the *Available Instance Types* table.

An array that contains the instance's layer IDs.

The stack ID.

The default OpsWorks Stacks agent version. You have the following options:. - `INHERIT` - Use the stack's default agent version setting. - *version_number* - Use the specified agent version. This value overrides the stack's default setting. To update the agent version, edit the instance configuration and specify a new version. OpsWorks Stacks installs that version on the instance. The default setting is `INHERIT` . To specify an agent version, you must use the complete version number, not the abbreviated number shown on the console. For a list of available agent version numbers, call `DescribeAgentVersions` . AgentVersion cannot be set to Chef 12.2.

A custom AMI ID to be used to create the instance. The AMI should be based on one of the supported operating systems. For more information, see [Using Custom AMIs](https://docs.aws.amazon.com/opsworks/latest/userguide/workinginstances-custom-ami.html) . > If you specify a custom AMI, you must set `Os` to `Custom` .

The instance architecture. The default option is `x86_64` . Instance types do not necessarily support both architectures. For a list of the architectures that are supported by the different instance types, see [Instance Families and Types](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html) .

For load-based or time-based instances, the type. Windows stacks can use only time-based instances.

The Availability Zone of the OpsWorks instance, such as `us-east-2a` .

An array of `BlockDeviceMapping` objects that specify the instance's block devices. For more information, see [Block Device Mapping](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html) . Note that block device mappings are not supported for custom AMIs.

Whether to create an Amazon EBS-optimized instance.

A list of Elastic IP addresses to associate with the instance.

The instance host name. The following are character limits for instance host names. - Linux-based instances: 63 characters - Windows-based instances: 15 characters

Whether to install operating system and package updates when the instance boots. The default value is `true` . To control when updates are installed, set this value to `false` . You must then update your instances manually by using `CreateDeployment` to run the `update_dependencies` stack command or by manually running `yum` (Amazon Linux) or `apt-get` (Ubuntu) on the instances. > We strongly recommend using the default value of `true` to ensure that your instances have the latest security updates.

The instance's operating system, which must be set to one of the following. - A supported Linux operating system: An Amazon Linux version, such as `Amazon Linux 2` , `Amazon Linux 2018.03` , `Amazon Linux 2017.09` , `Amazon Linux 2017.03` , `Amazon Linux 2016.09` , `Amazon Linux 2016.03` , `Amazon Linux 2015.09` , or `Amazon Linux 2015.03` . - A supported Ubuntu operating system, such as `Ubuntu 18.04 LTS` , `Ubuntu 16.04 LTS` , `Ubuntu 14.04 LTS` , or `Ubuntu 12.04 LTS` . - `CentOS Linux 7` - `Red Hat Enterprise Linux 7` - A supported Windows operating system, such as `Microsoft Windows Server 2012 R2 Base` , `Microsoft Windows Server 2012 R2 with SQL Server Express` , `Microsoft Windows Server 2012 R2 with SQL Server Standard` , or `Microsoft Windows Server 2012 R2 with SQL Server Web` . - A custom AMI: `Custom` . Not all operating systems are supported with all versions of Chef. For more information about the supported operating systems, see [OpsWorks Stacks Operating Systems](https://docs.aws.amazon.com/opsworks/latest/userguide/workinginstances-os.html) . The default option is the current Amazon Linux version. If you set this parameter to `Custom` , you must use the `CreateInstance` action's AmiId parameter to specify the custom AMI that you want to use. Block device mappings are not supported if the value is `Custom` . For more information about how to use custom AMIs with OpsWorks Stacks, see [Using Custom AMIs](https://docs.aws.amazon.com/opsworks/latest/userguide/workinginstances-custom-ami.html) .

The instance root device type. For more information, see [Storage for the Root Device](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ComponentsAMIs.html#storage-for-the-root-device) .

The instance's Amazon EC2 key-pair name.

The ID of the instance's subnet. If the stack is running in a VPC, you can use this parameter to override the stack's default subnet ID value and direct OpsWorks Stacks to launch the instance in a different subnet.

The instance's tenancy option. The default option is no tenancy, or if the instance is running in a VPC, inherit tenancy settings from the VPC. The following are valid values for this parameter: `dedicated` , `default` , or `host` . Because there are costs associated with changes in tenancy options, we recommend that you research tenancy options before choosing them for your instances. For more information about dedicated hosts, see [Dedicated Hosts Overview](https://docs.aws.amazon.com/ec2/dedicated-hosts/) and [Amazon EC2 Dedicated Hosts](https://docs.aws.amazon.com/ec2/dedicated-hosts/) . For more information about dedicated instances, see [Dedicated Instances](https://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/dedicated-instance.html) and [Amazon EC2 Dedicated Instances](https://docs.aws.amazon.com/ec2/purchasing-options/dedicated-instances/) .

The time-based scaling configuration for the instance.

The instance's virtualization type, `paravirtual` or `hvm` .

A list of OpsWorks volume IDs to associate with the instance. For more information, see [`AWS::OpsWorks::Volume`](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-opsworks-volume.html) .