asmcli reference


The asmcli is a Google-provided tool that you can use to install or upgrade Cloud Service Mesh. If you let it, asmcli will configure your project and cluster as follows:

  • Grant you the required Identity and Access Management (IAM) permissions on your Google Cloud project.
  • Enable the required Google APIs on your Google Cloud project.
  • Set a label on the cluster that identifies the mesh.
  • Create a service account that lets data plane components, such as the sidecar proxy, securely access your project's data and resources.
  • Register the cluster to the fleet if it isn't already registered.

Just include the --enable_all flag when you run asmcli to let it configure your project and cluster. For more information about asmcli options and flags, see the asmcli reference.

Next, asmcli configures YAML files with your project and cluster information. These configuration files are needed to install the Cloud Service Mesh control plane.

If you are new to Cloud Service Mesh and Istio, skip ahead to Supported platforms. The next section is intended to help existing Cloud Service Mesh upgrade to 1.21.

Transitioning to asmcli

The asmcli takes the place of istioctl install and install_asm. Although you can still use the legacy tools in Cloud Service Mesh 1.11, we are deprecating them and they will no longer be supported in Cloud Service Mesh 1.12 and later. Please update your scripts and tools to use asmcli.

All clusters must be registered to a fleet. See Fleet requirements for details.

Transitioning from install_asm

If you are familiar with install_asm, asmcli is similar but with the following notable differences:

  • You use asmcli install for new installations and upgrades. There isn't a --mode option like with install_asm. When you run asmcli install, it checks to see if there's an existing control plane on the cluster. If there isn't an existing control plane, asmcli installs Cloud Service Mesh. If the cluster has an existing control plane (either an Cloud Service Mesh control plane or an open source Istio control plane):

    • If the revision label on the existing control plane doesn't match the revision label for the new control plane, asmcli does a canary upgrade.

    • If the control plane revision labels are the same, asmcli does an in-place upgrade.

  • Most of the asmcli options and flags behave the same as the ones for install_asm.

Transitioning from istioctl install

If you are familiar with istioctl install, if you normally pass an IstioOperator YAML file via the -f command-line argument to configure the control plane, you can pass the file to asmcli using the --custom_overlay option. In the Cloud Service Mesh documentation, we refer to these files as overlay files.

Supported platforms

Cloud Service Mesh installations on the list of Supported platforms can be configured or upgraded by asmcli.

However, not all features are available on the platforms outside of Google Cloud. For details, see In-cluster control plane supported features.

asmcli reference

This section describes the available arguments to asmcli.


Identify the cluster You have the following options to identify the cluster:

GKE only

-p|--project_id CLUSTER_PROJECT_ID
The project ID that the cluster was created in.
-n|--cluster_name CLUSTER_NAME
The name of the cluster.
-l|--cluster_location CLUSTER_LOCATION
Either the zone (for single-zone clusters) or region (for regional clusters) that the cluster was created in.

All platforms

--kubeconfig KUBECONFIG_FILE The full path to the kubeconfig file. The environment variable $PWD doesn't work here.

--ctx|--context KUBE_CONTEXT The kubeconfig context to use. If not specified, asmcli uses the default context.

-c|--ca {mesh_ca|gcp_cas|citadel}

The certificate authority (CA) to use to manage mutual TLS certificates. Specify mesh_ca to use Cloud Service Mesh certificate authority (Cloud Service Mesh certificate authority), gcp_cas to use Certificate Authority Service, or citadel to use the Istio CA. Managed Cloud Service Mesh does not support Istio CA. See the following for additional information:


Use --channel with a specific Cloud Service Mesh release channel to provision the Control Plane revision associated with that release channel. For example, --channel rapid, --channel regular, and --channel stable. This flag is required when configuring certain Cloud Service Mesh features on GKE Autopilot clusters.

--channel option is no longer supported for Managed Cloud Service Mesh as mentioned in CSM Release Notes. Release channel is determined based on your GKE cluster release channel. For more information, see Managed Cloud Service Mesh release channels.

--co|--custom_overlay OVERLAY_FILE
Use --custom_overly with the name of a YAML file (referred to as an overlay file) containing the IstioOperator custom resource to configure the in-cluster control plane. You specify an overlay file to enable a feature that isn't enabled by default. Managed Cloud Service Mesh doesn't support the IstioOperator API, so you can't use --custom_overlay to configure the managed control plane. asmcli must be able to locate the overlay file, so it either needs to be in the same directory as asmcli, or you can specify a relative path. To add multiple files, specify --co|--custom_overlay and the filename, for example: --co overlay_file1.yaml --co overlay_file2.yaml --co overlay_file3.yaml
--hub-registration-extra-flags HUB_REGISTRATION_EXTRA_FLAGS
If using attached Amazon EKS clusters, use --hub-registration-extra-flags to register the cluster to the fleet if it isn't already registered.
-k|--key_file FILE_PATH
The key file for a service account. Omit this option if you aren't using a service account.
--network_id NETWORK_ID
Use --network_id to set the label applied to the istio-system namespace. For GKE, --network_id defaults to the network name for the cluster. For other environments, default will be used.
-o|--option OVERLAY_FILE

The name of the overlay file (without the .yaml extension) that asmcli downloads from the anthos-service-mesh repository to enable an optional feature. You need internet connectivity to use --option. The --option and --custom_overlay options are similar, but they have slightly different behavior:

  • Use --custom_overlay when you need to change the settings in the overlay file.

  • Use --option to enable a feature that doesn't require changes to the overlay file, for example, to configure audit policies for your services.

To add multiple files, specify -o|--option and the filename, for example: -o option_file1 -o option_file2 -o option_file3

-D|--output_dir DIR_PATH

If not specified, asmcli creates a temporary directory where it downloads files and configurations necessary for installing Cloud Service Mesh. Specify the --output-dir flag to specify a relative path to a directory to use instead. Upon completion, the specified directory contains the asm and the istio-1.21.4-asm.5 subdirectories. The asm directory contains the configuration for the installation. The istio-1.21.4-asm.5 directory contains the extracted contents of installation file, which contains istioctl, samples, and manifests. If you specify --output-dir and the directory already contains the necessary files, asmcli uses those files instead of downloading them again.

--platform PLATFORM {gcp|multicloud}

The platform or the provider of the Kubernetes cluster. Defaults to gcp (for GKE clusters). For all other platforms use, multicloud.

-r|--revision_name REVISION NAME

A revision label is a key-value pair that is set on the control plane. The revision label key is always By default, asmcli sets the value for the revision label based on the Cloud Service Mesh version, for example: asm-1214-5. Include this option if you want to override the default value and specify your own. The REVISION NAME argument must be a DNS-1035 label. This means the name must:

  • contain at most 63 characters
  • contain only lowercase alphanumeric characters or '-'
  • start with an alphabetic character
  • end with an alphanumeric character

The regex used for validation is: '[a-z]([-a-z0-9]*[a-z0-9])?'

-s|--service_account ACCOUNT
The name of a service account used to install Cloud Service Mesh. If not specified, the active user account in the current gcloud configuration is used. If you need to change the active user account, run gcloud auth login.

Options for Istio CA custom certificate

If you specified --ca citadel and you are using a custom CA, include the following options:

  • --ca_cert FILE_PATH: The intermediate certificate
  • --ca_key FILE_PATH: The key for the intermediate certificate
  • --root_cert FILE_PATH: The root certificate
  • --cert_chain FILE_PATH: The certificate chain

For more information, see Plugging in existing CA Certificates.

Enablement flags

The flags that start with --enable let asmcli enable the required Google APIs, set required Identity and Access Management (IAM) permissions, and update your cluster. If you prefer, you can update your project and cluster yourself before running asmcli. All of the enablement flags are incompatible with asmcli validate. If you specify an enablement flag when you run asmcli validate, the command terminates with an error.

Allow asmcli to perform all of the individual enable actions described below.
Allow asmcli to attempt to bind the Google Cloud user or service account running asmcli to the cluster-admin role on your cluster. asmcli determines the user account from the gcloud config get core/account command. If you are running asmcli locally with a user account, make sure that you call the gcloud auth login command before running asmcli. If you need to change the user account, run the gcloud config set core/account GCP_EMAIL_ADDRESS command where GCP_EMAIL_ADDRESS is the account that you use to log in to Google Cloud.
Allow asmcli to set required cluster labels.

Allow asmcli to enable the following required Google Cloud managed services and components:


Allow asmcli to enable all required Google APIs.


Allow asmcli to set the required IAM permissions.


Allow the script to initialize the meshconfig endpoint on your behalf. Implied by --enable_gcp_components and --managed.


Allow asmcli to create the root istio-system namespace.


Allow asmcli to register the cluster to the project that the cluster is in. If you don't include this flag, follow the steps in Registering a cluster to manually register the cluster. Note that unlike the other enablement flags, --enable_registration is only included in --enable_all when you specify an option (such as --option hub-meshca) that requires cluster registration. Otherwise, you need to specify this flag separately.

Other flags

Print commands, but don't execute them.
Register a cluster to a fleet using the fleet's host project ID. This flag is required for non-Google Cloud clusters. When not provided for Google Cloud clusters, it defaults to the cluster's project ID. You can run asmcli install along with --fleet_id prior to the installation, or as part of the installation by passing the --enable-registration and --fleet-id flags. This setting cannot be changed after it is configured.
Provision a remote, managed control plane instead of installing one in-cluster.
Perform an offline installation using the pre-downloaded package in the output directory. If the directory is not specified or does not contain the required files, the script will exit with error.
Perform the specified steps to set up the current user/cluster but doesn't install anything.
Run validation but don't update the project or cluster and don't install Cloud Service Mesh. This flag is incompatible with the enablement flags. asmcli terminates with an error if you specify --only_validate with any enablement flag.
Instead of installing Cloud Service Mesh, print all of the compiled YAML to standard output (stdout). All other output is written to standard error (stderr), even if it would normally go to stdout. asmcli skips all validations and setup when you specify this flag.
By default, asmcli deploys the Canonical Service controller to your cluster. If you don't want asmcli to deploy the controller, specify --disable_canonical_service. For more information, refer to Enabling and disabling the Canonical Service controller.
Show a help message describing the options and flags and exit.
Use the managed CNI. If this flag is not passed, asmcli will apply the static CNI manifests.
If your organization enforces VPC Service Controls for your project, you must configure managed Cloud Service Mesh with the --use_vpcsc flag. Otherwise the installation will fail security controls.
As asmcli runs, it prints the command that it will run next. With the --verbose flag, asmcli prints the command after execution as well.
Print the version of asmcli and exit. If you don't have the most recent version, you can download the most recent version of asmcli_1.21.