gcloud compute instance-groups managed update-instances

NAME
gcloud compute instance-groups managed update-instances - immediately update selected instances in a Compute Engine managed instance group
SYNOPSIS
gcloud compute instance-groups managed update-instances NAME --instances=INSTANCE,[INSTANCE,…] [--minimal-action=MINIMAL_ACTION; default="none"] [--most-disruptive-allowed-action=MOST_DISRUPTIVE_ALLOWED_ACTION; default="replace"] [--region=REGION     | --zone=ZONE] [GCLOUD_WIDE_FLAG …]
DESCRIPTION
When using a managed instance group, it's possible that your intended specification for a VM is different from the current state of that VM. For example, this can happen due to changes to the group's target instance template. This command enables you to initiate the update process on the given set of instances instantly, thus when your Managed Instance Group is stable you can be sure that all the changes were applied.

gcloud compute instance-groups managed update-instances allows you to specify the least and the most disruptive actions that can be performed while updating the instances. This way you can reduce the risk of rolling out too many changes at once. Possible actions are: none, refresh, restart and replace. The level of disruption to the instance is ordered as: none < refresh < restart < replace.

POSITIONAL ARGUMENTS
NAME
Name of the managed instance group to operate on.
REQUIRED FLAGS
--instances=INSTANCE,[INSTANCE,…]
Names of instances to update.
OPTIONAL FLAGS
--minimal-action=MINIMAL_ACTION; default="none"
Perform at least this action on each instance while updating. MINIMAL_ACTION must be one of:
none
No action
refresh
Apply properties that are possible to apply without stopping the instance
replace
Delete the instance and create it again
restart
Stop the instance and start it again
--most-disruptive-allowed-action=MOST_DISRUPTIVE_ALLOWED_ACTION; default="replace"
Perform at most this action on each instance while updating. If the update requires a more disruptive action than the one specified here, then the update will fail and no changes will be made. MOST_DISRUPTIVE_ALLOWED_ACTION must be one of:
none
No action
refresh
Apply properties that are possible to apply without stopping the instance
replace
Delete the instance and create it again
restart
Stop the instance and start it again
At most one of these may be specified:
--region=REGION
Region of the managed instance group to operate on. If not specified, you may be prompted to select a region (interactive mode only).

A list of regions can be fetched by running: 

gcloud compute regions list

Overrides the default compute/region property value for this command invocation.

--zone=ZONE
Zone of the managed instance group to operate on. If not specified, you may be prompted to select a zone (interactive mode only).

A list of zones can be fetched by running: 

gcloud compute zones list

Overrides the default compute/zone property value for this command invocation.

GCLOUD WIDE FLAGS
These flags are available to all commands: --account, --billing-project, --configuration, --flags-file, --flatten, --format, --help, --impersonate-service-account, --log-http, --project, --quiet, --trace-token, --user-output-enabled, --verbosity.

Run $ gcloud help for details.

EXAMPLES
To update instances instance-1, instance-2 in my-group, with minimal-action=none and most-disruptive-allowed-action=restart, run: 
gcloud compute instance-groups managed update-instances  my-group --instances=instance-1,instance2  --minimal-action=none
      --most-disruptive-allowed-action=restart
NOTES
These variants are also available: 
gcloud alpha compute instance-groups managed update-instances

gcloud beta compute instance-groups managed update-instances