AWS Tools for Windows PowerShell
Command Reference

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Synopsis

Calls the AWS Auto Scaling DetachInstances API operation.

Syntax

Dismount-ASInstance
-InstanceId <String[]>
-AutoScalingGroupName <String>
-ShouldDecrementDesiredCapacity <Boolean>
-Select <String>
-PassThru <SwitchParameter>
-Force <SwitchParameter>

Description

Removes one or more instances from the specified Auto Scaling group. After the instances are detached, you can manage them independent of the Auto Scaling group. If you do not specify the option to decrement the desired capacity, Amazon EC2 Auto Scaling launches instances to replace the ones that are detached. If there is a Classic Load Balancer attached to the Auto Scaling group, the instances are deregistered from the load balancer. If there are target groups attached to the Auto Scaling group, the instances are deregistered from the target groups. For more information, see Detach EC2 Instances from Your Auto Scaling Group in the Amazon EC2 Auto Scaling User Guide.

Note: For scripts written against earlier versions of this module this cmdlet can also be invoked with the alias, Dismount-ASInstances.

Parameters

-AutoScalingGroupName <String>
The name of the Auto Scaling group.
Required?True
Position?2
Accept pipeline input?True (ByPropertyName)
This parameter overrides confirmation prompts to force the cmdlet to continue its operation. This parameter should always be used with caution.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-InstanceId <String[]>
The IDs of the instances. You can specify up to 20 instances.
Required?False
Position?1
Accept pipeline input?True (ByValue, ByPropertyName)
AliasesInstanceIds
-PassThru <SwitchParameter>
Changes the cmdlet behavior to return the value passed to the InstanceId parameter. The -PassThru parameter is deprecated, use -Select '^InstanceId' instead. This parameter will be removed in a future version.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-Select <String>
Use the -Select parameter to control the cmdlet output. The default value is 'Activities'. Specifying -Select '*' will result in the cmdlet returning the whole service response (Amazon.AutoScaling.Model.DetachInstancesResponse). Specifying the name of a property of type Amazon.AutoScaling.Model.DetachInstancesResponse will result in that property being returned. Specifying -Select '^ParameterName' will result in the cmdlet returning the selected cmdlet parameter value.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-ShouldDecrementDesiredCapacity <Boolean>
Indicates whether the Auto Scaling group decrements the desired capacity value by the number of instances detached.
Required?True
Position?Named
Accept pipeline input?True (ByPropertyName)

Common Credential and Region Parameters

-AccessKey <String>
The AWS access key for the user account. This can be a temporary access key if the corresponding session token is supplied to the -SessionToken parameter.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesAK
-Credential <AWSCredentials>
An AWSCredentials object instance containing access and secret key information, and optionally a token for session-based credentials.
Required?False
Position?Named
Accept pipeline input?True (ByValue, ByPropertyName)
-EndpointUrl <String>
The endpoint to make the call against.Note: This parameter is primarily for internal AWS use and is not required/should not be specified for normal usage. The cmdlets normally determine which endpoint to call based on the region specified to the -Region parameter or set as default in the shell (via Set-DefaultAWSRegion). Only specify this parameter if you must direct the call to a specific custom endpoint.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-NetworkCredential <PSCredential>
Used with SAML-based authentication when ProfileName references a SAML role profile. Contains the network credentials to be supplied during authentication with the configured identity provider's endpoint. This parameter is not required if the user's default network identity can or should be used during authentication.
Required?False
Position?Named
Accept pipeline input?True (ByValue, ByPropertyName)
-ProfileLocation <String>
Used to specify the name and location of the ini-format credential file (shared with the AWS CLI and other AWS SDKs)If this optional parameter is omitted this cmdlet will search the encrypted credential file used by the AWS SDK for .NET and AWS Toolkit for Visual Studio first. If the profile is not found then the cmdlet will search in the ini-format credential file at the default location: (user's home directory)\.aws\credentials.If this parameter is specified then this cmdlet will only search the ini-format credential file at the location given.As the current folder can vary in a shell or during script execution it is advised that you use specify a fully qualified path instead of a relative path.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesAWSProfilesLocation, ProfilesLocation
-ProfileName <String>
The user-defined name of an AWS credentials or SAML-based role profile containing credential information. The profile is expected to be found in the secure credential file shared with the AWS SDK for .NET and AWS Toolkit for Visual Studio. You can also specify the name of a profile stored in the .ini-format credential file used with the AWS CLI and other AWS SDKs.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesStoredCredentials, AWSProfileName
-Region <Object>
The system name of an AWS region or an AWSRegion instance. This governs the endpoint that will be used when calling service operations. Note that the AWS resources referenced in a call are usually region-specific.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesRegionToCall
-SecretKey <String>
The AWS secret key for the user account. This can be a temporary secret key if the corresponding session token is supplied to the -SessionToken parameter.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesSK, SecretAccessKey
-SessionToken <String>
The session token if the access and secret keys are temporary session-based credentials.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesST

Outputs

This cmdlet returns a collection of Amazon.AutoScaling.Model.Activity objects. The service call response (type Amazon.AutoScaling.Model.DetachInstancesResponse) can also be referenced from properties attached to the cmdlet entry in the $AWSHistory stack.

Examples

Example 1

PS C:\> Dismount-ASInstance -InstanceId i-93633f9b -AutoScalingGroupName my-asg -ShouldDecrementDesiredCapacity $true

ActivityId : 06733445-ce94-4039-be1b-b9f1866e276e
AutoScalingGroupName : my-asg
Cause : At 2015-11-20T22:34:59Z instance i-93633f9b was detached in response to a user request, shrinking
the capacity from 2 to 1.
Description : Detaching EC2 instance: i-93633f9b
Details : {"Availability Zone":"us-west-2b","Subnet ID":"subnet-5264e837"}
EndTime :
Progress : 50
StartTime : 11/20/2015 2:34:59 PM
StatusCode : InProgress
StatusMessage :
This example detaches the specified instance from the specified Auto Scaling group and decreases the desired capacity so that Auto Scaling does not launch a replacement instance.

Example 2

PS C:\> Dismount-ASInstance -InstanceId i-7bf746a2 -AutoScalingGroupName my-asg -ShouldDecrementDesiredCapacity $false

ActivityId : f43a3cd4-d38c-4af7-9fe0-d76ec2307b6d
AutoScalingGroupName : my-asg
Cause : At 2015-11-20T22:34:59Z instance i-7bf746a2 was detached in response to a user request.
Description : Detaching EC2 instance: i-7bf746a2
Details : {"Availability Zone":"us-west-2b","Subnet ID":"subnet-5264e837"}
EndTime :
Progress : 50
StartTime : 11/20/2015 2:34:59 PM
StatusCode : InProgress
StatusMessage :
This example detaches the specified instance from the specified Auto Scaling group without decreasing the desired capacity. Auto Scaling launches a replacement instance.

Supported Version

AWS Tools for PowerShell: 2.x.y.z