# LaunchConfiguration
Describes a launch configuration.
## Contents
** CreatedTime **
The creation date and time for the launch configuration.
Type: Timestamp
Required: Yes
** ImageId **
The ID of the Amazon Machine Image (AMI) to use to launch your EC2 instances. For more information, see [Find a Linux AMI](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/finding-an-ami.html) in the *Amazon EC2 User Guide*.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: Yes
** InstanceType **
The instance type for the instances. For information about available instance types, see [Available instance types](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html#AvailableInstanceTypes) in the *Amazon EC2 User Guide*.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: Yes
** LaunchConfigurationName **
The name of the launch configuration.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: Yes
** AssociatePublicIpAddress **
Specifies whether to assign a public IPv4 address to the group's instances. If the instance is launched into a default subnet, the default is to assign a public IPv4 address, unless you disabled the option to assign a public IPv4 address on the subnet. If the instance is launched into a nondefault subnet, the default is not to assign a public IPv4 address, unless you enabled the option to assign a public IPv4 address on the subnet. For more information, see [Provide network connectivity for your Auto Scaling instances using Amazon VPC](https://docs.aws.amazon.com/autoscaling/ec2/userguide/asg-in-vpc.html) in the *Amazon EC2 Auto Scaling User Guide*.
Type: Boolean
Required: No
** BlockDeviceMappings.member.N **
The block device mapping entries that define the block devices to attach to the instances at launch. By default, the block devices specified in the block device mapping for the AMI are used. For more information, see [Block device mappings](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html) in the *Amazon EC2 User Guide*.
Type: Array of [BlockDeviceMapping](API_BlockDeviceMapping.md) objects
Required: No
** ClassicLinkVPCId **
Available for backward compatibility.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: No
** ClassicLinkVPCSecurityGroups.member.N **
Available for backward compatibility.
Type: Array of strings
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: No
** EbsOptimized **
Specifies whether the launch configuration is optimized for EBS I/O (`true`) or not (`false`). For more information, see [Amazon EBS-optimized instances](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-optimized.html) in the *Amazon EC2 User Guide*.
Type: Boolean
Required: No
** IamInstanceProfile **
The name or the Amazon Resource Name (ARN) of the instance profile associated with the IAM role for the instance. The instance profile contains the IAM role. For more information, see [IAM role for applications that run on Amazon EC2 instances](https://docs.aws.amazon.com/autoscaling/ec2/userguide/us-iam-role.html) in the *Amazon EC2 Auto Scaling User Guide*.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 1600.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: No
** InstanceMonitoring **
Controls whether instances in this group are launched with detailed (`true`) or basic (`false`) monitoring.
For more information, see [Configure monitoring for Auto Scaling instances](https://docs.aws.amazon.com/autoscaling/latest/userguide/enable-as-instance-metrics.html) in the *Amazon EC2 Auto Scaling User Guide*.
Type: [InstanceMonitoring](API_InstanceMonitoring.md) object
Required: No
** KernelId **
The ID of the kernel associated with the AMI.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: No
** KeyName **
The name of the key pair.
For more information, see [Amazon EC2 key pairs and Amazon EC2 instances](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html) in the *Amazon EC2 User Guide*.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: No
** LaunchConfigurationARN **
The Amazon Resource Name (ARN) of the launch configuration.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 1600.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: No
** MetadataOptions **
The metadata options for the instances. For more information, see [Configure the instance metadata options](https://docs.aws.amazon.com/autoscaling/ec2/userguide/create-launch-config.html#launch-configurations-imds) in the *Amazon EC2 Auto Scaling User Guide*.
Type: [InstanceMetadataOptions](API_InstanceMetadataOptions.md) object
Required: No
** PlacementTenancy **
The tenancy of the instance, either `default` or `dedicated`. An instance with `dedicated` tenancy runs on isolated, single-tenant hardware and can only be launched into a VPC.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 64.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: No
** RamdiskId **
The ID of the RAM disk associated with the AMI.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: No
** SecurityGroups.member.N **
A list that contains the security groups to assign to the instances in the Auto Scaling group. For more information, see [Control traffic to your AWS resources using security groups](https://docs.aws.amazon.com/vpc/latest/userguide/vpc-security-groups.html) in the *Amazon Virtual Private Cloud User Guide*.
Type: Array of strings
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: No
** SpotPrice **
The maximum hourly price to be paid for any Spot Instance launched to fulfill the request. Spot Instances are launched when the price you specify exceeds the current Spot price. For more information, see [Requesting Spot Instances for fault-tolerant and flexible applications](https://docs.aws.amazon.com/autoscaling/ec2/userguide/launch-template-spot-instances.html) in the *Amazon EC2 Auto Scaling User Guide*.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Required: No
** UserData **
The user data to make available to the launched EC2 instances. For more information, see [Instance metadata and user data](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html) in the *Amazon EC2 User Guide*. If you are using a command line tool, base64-encoding is performed for you, and you can load the text from a file. Otherwise, you must provide base64-encoded text. User data is limited to 16 KB.
Type: String
Length Constraints: Maximum length of 21847.
Pattern: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`
Required: No
## See Also
For more information about using this API in one of the language-specific AWS SDKs, see the following:
+ [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/autoscaling-2011-01-01/LaunchConfiguration)
+ [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/autoscaling-2011-01-01/LaunchConfiguration)
+ [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/autoscaling-2011-01-01/LaunchConfiguration)