Add SSH keys to VMs

Linux Windows

This document describes how to add SSH keys to virtual machine (VM) instances that use OS Login and VMs that use metadata-based SSH keys. If you or your organization administrator hasn't enabled OS Login, your VMs use metadata-based SSH keys.

Key Point: The procedures in this document are optional. If you connect to VMs using the Google Cloud console or the Google Cloud CLI, Compute Engine creates and manages SSH keys on your behalf.

Before you begin

• For information about managing access to your Compute Engine VMs, see Choosing an access method.
• If you haven't already, create an SSH key pair.
• If you haven't already, set up authentication. Authentication verifies your identity for access to Google Cloud services and APIs. To run code or samples from a local development environment, you can authenticate to Compute Engine by selecting one of the following options:

  Select the tab for how you plan to use the samples on this page:

  Console

  When you use the Google Cloud console to access Google Cloud services and APIs, you don't need to set up authentication.

  gcloud

  1. Install the Google Cloud CLI. After installation, initialize the Google Cloud CLI by running the following command:

     gcloud init

     If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.

     Note: If you installed the gcloud CLI previously, make sure you have the latest version by running gcloud components update.
  2. Set a default region and zone.

  Terraform

  To use the Terraform samples on this page in a local development environment, install and initialize the gcloud CLI, and then set up Application Default Credentials with your user credentials.

  Install the Google Cloud CLI.

  If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.

  Note: If you installed the gcloud CLI previously, make sure you have the latest version by running gcloud components update.

  If you're using a local shell, then create local authentication credentials for your user account:

  gcloud auth application-default login

  You don't need to do this if you're using Cloud Shell.

  If an authentication error is returned, and you are using an external identity provider (IdP), confirm that you have signed in to the gcloud CLI with your federated identity.

  For more information, see Set up authentication for a local development environment.

  REST

  To use the REST API samples on this page in a local development environment, you use the credentials you provide to the gcloud CLI.

  Install the Google Cloud CLI.

  If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.

  Note: If you installed the gcloud CLI previously, make sure you have the latest version by running gcloud components update.

  For more information, see Authenticate for using REST in the Google Cloud authentication documentation.

Add keys to VMs that use OS Login

VMs that use OS Login accept SSH keys that are associated with your Google Account. You can associate a public SSH key with your Google Account using the gcloud CLI or using the OS Login API. If you're an administrator for your organization, you can add SSH keys to user accounts using the Directory API.

When you add SSH keys to your Google Account, Compute Engine generates a username for you by combining the username and domain from the email associated with your Google Account. For example, if your email address is [e-mail], your username is cloudysanfrancisco_gmail_com. If you add an SSH key in a project that is outside of your organization, your username is prefixed with ext_, for example, ext_cloudysanfrancisco_gmail_com. Your organization administrator can customize your username using the Directory API. If you already have a username configured, Compute Engine uses that username when you add SSH keys.

Note: VMs that have been configured to require SSH certificates reject connections from unsigned SSH keys.

Permissions required for this task

To perform this task, you must have the following permissions:

• All permissions in the Compute OS Login External User role, if you add an SSH key in a project outside of your organization.

gcloud

1. In the Google Cloud console, activate Cloud Shell.

   Activate Cloud Shell

   At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.

2. To add a public SSH key to your account, use the gcloud compute os-login ssh-keys add command:

   gcloud compute os-login ssh-keys add \
      --key-file=KEY_FILE_PATH \
      --project=PROJECT \
      --ttl=EXPIRE_TIME
   

   Replace the following:

   • KEY_FILE_PATH: the path to the public SSH key on your workstation. The key must use the public-openssh format
   • PROJECT: Optional: a project where you intend to use your SSH key. Specify this field to use your SSH key in a project outside of your organization, or you are not a member of a Cloud Identity organization

   • EXPIRE_TIME: Optional: the expiration time for the SSH key

     For example, if you specify 30m the SSH key expires after 30 minutes.

     This flag uses the following units:

     • s for seconds
     • m for minutes
     • h for hours
     • d for days

Terraform

To add a public SSH key to your account, use the google_client_openid_userinfo resource along with the google_os_login_ssh_public_key resource.

data "google_client_openid_userinfo" "me" {
}

resource "google_os_login_ssh_public_key" "default" {
  user = data.google_client_openid_userinfo.me.email
  key  = file("id_rsa.pub") # path/to/ssl/id_rsa.pub
}

REST

To add a public SSH key to your account, use the OS Login API users.importSshPublicKey method:

POST https://oslogin.googleapis.com/v1/users/ACCOUNT_EMAIL:importSshPublicKey

{
 "key": "SSH_KEY",
 "expirationTimeUsec": "EXPIRATION_TIMESTAMP"
}

Replace the following:

• ACCOUNT_EMAIL: the email address associated with your account
• SSH_KEY: the public key that you want to add to the account
• EXPIRATION_TIMESTAMP: the expiration time for the key, in microseconds since epoch (1 second = 10⁶ microseconds)

Add SSH keys to VMs that use metadata-based SSH keys

Caution: If you manage SSH keys in metadata, you might disrupt the ability of your project members to connect to VMs. Additionally, you risk granting users, including users outside of your project, unintended access to VMs. Users and service accounts that have the ability to modify project metadata can add SSH keys for all VMs in the project except for VMs that block project-level SSH keys. For more information, see risks of manual key management.

VMs that don't use OS Login store SSH keys in Compute Engine project and instance metadata. If OS Login is enabled for a VM, then the VM's guest agent ignores the keys stored in metadata.

You can use SSH keys stored in project metadata to access all VMs in a project. You can use SSH keys stored in instance metadata to access individual VMs.

Compute Engine doesn't automatically remove expired SSH keys from metadata at expiration time, but expired keys can't be used to establish new connections to VMs. If you want to remove expired keys from metadata, see Remove SSH keys from VMs that use metadata-based keys.

You can add a public SSH key to project or VM instance metadata using the Google Cloud console, the gcloud CLI, or REST. You can't set zonal metadata values for SSH keys.

Caution: Public SSH keys that you add directly to a VM's ~/.ssh/authorized_keys files might be overwritten by the VM's guest agent. We recommend that you add keys using the supported Google Cloud console, gcloud CLI, or REST methods as described in the following sections.

Add SSH keys to project metadata

You can add a public SSH key to project metadata to access all VMs in a project, except VMs that block project-wide SSH keys. For more information about blocking project-wide SSH keys, see Block SSH keys from VMs that use metadata-based SSH keys.

Permissions required for this task

To perform this task, you must have the following permissions:

• compute.projects.setCommonInstanceMetadata on the project.
• iam.serviceAccounts.actAs on the project. For more information about service account permissions, see Roles for service account authentication.

Console

To add a public SSH key to project metadata using the Google Cloud console, do the following:

1. In the Google Cloud console, go to the Metadata page.

   Go to Metadata

2. Click the SSH keys tab.

3. Click Edit.

4. Click Add item.

5. In the SSH key field that opens, add your public SSH key. The key must be in one of the following formats:

   • Format for a key without an expiration time:

     KEY_VALUE USERNAME

   • Format for a key with an expiration time:

     KEY_VALUE google-ssh {"userName":"USERNAME","expireOn":"EXPIRE_TIME"}

   Replace the following:

   • KEY_VALUE: the public SSH key value
   • USERNAME: your username. For example, cloudysanfrancisco or cloudysanfrancisco_gmail_com.

     For Linux VMs, the USERNAME can't be root, unless you configure your VM to allow root login. For more information, see Connect to Linux VMs as the root user.

     For Windows VMs that use Active Directory (AD), the username must be prepended with the AD domain, in the format of DOMAIN\. For example, the user cloudysanfrancisco within the ad.example.com AD has a USERNAME of example\cloudysanfrancisco.

   • EXPIRE_TIME: the time the key expires, in ISO 8601 format. For example: 2021-12-04T20:12:00+0000

6. Click Save.

gcloud

In the Google Cloud console, activate Cloud Shell.

Activate Cloud Shell

At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.

1. If there are existing SSH keys in project metadata, you must re-add them to project metadata every time you add a new SSH key using the gcloud CLI. If you don't re-add your existing keys, adding a new key erases the existing keys.

   To add a public SSH key to project metadata using the gcloud CLI, do the following:

   1. If your project already has project-wide public SSH keys, get them from metadata and add them to a new file:

      1. Run the gcloud compute project-info describe command to get the SSH keys for the project:

         gcloud compute project-info describe \
          --format="value(commonInstanceMetadata[items][ssh-keys])"
         

         The output is similar to the following:

         username:ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQ... username:ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQ...
         

      2. Copy the ssh-keys metadata value.

      3. Create and open a new text file on your workstation.

      4. In the file, paste the list of keys that you just copied.

      5. Add your new key at the end of the list, in one of the following formats:

         • Format for a key without an expiration time:

           USERNAME:KEY_VALUE

         • Format for a key with an expiration time:

           USERNAME:KEY_VALUE google-ssh {"userName":"USERNAME","expireOn":"EXPIRE_TIME"}

         Replace the following:

         • KEY_VALUE: the public SSH key value
         • USERNAME: your username. For example, cloudysanfrancisco, or cloudysanfrancisco_gmail_com.

           For Linux VMs, the USERNAME can't be root, unless you configure your VM to allow root login. For more information, see Connecting to instances as the root user.

           For Windows VMs that use Active Directory (AD), the username must be prepended with the AD domain, in the format of DOMAIN\. For example, the user cloudysanfrancisco within the ad.example.com AD has a USERNAME of example\cloudysanfrancisco.

         • EXPIRE_TIME: the time the key expires, in ISO 8601 format. For example: 2021-12-04T20:12:00+0000

      6. Save and close the file.

   2. Run the gcloud compute project-info add-metadata command to set the project-wide ssh-keys value:

      gcloud compute project-info add-metadata --metadata-from-file=ssh-keys=KEY_FILE
      

      Replace KEY_FILE with one of the following:

      • The path to the file you created in the previous step, if the project had existing SSH keys
      • The path to your new public SSH key file, if the project didn't have existing SSH keys

Terraform

To add a public SSH key to your project metadata, use the google_compute_project_metadata resource.

resource "google_compute_project_metadata" "default" {
  metadata = {
    ssh-keys = <<EOF
      dev:ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILg6UtHDNyMNAh0GjaytsJdrUxjtLy3APXqZfNZhvCeT dev
      test:ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILg6UtHDNyMNAh0GjaytsJdrUxjtLy3APXqZfNZhvCeT test
    EOF
  }
}

REST

If there are existing SSH keys in project metadata, you must re-add them to project metadata every time you add a new SSH key using the the Compute Engine API. If you don't re-add your existing keys, adding a new key erases the existing keys.

To add a public SSH key to project metadata using the Compute Engine API, do the following:

1. Get the fingerprint and ssh-keys values from metadata by using the projects.get method

   GET https://compute.googleapis.com/compute/v1/projects/PROJECT_ID
   

   Replace PROJECT_ID with your project ID.

   The response is similar to the following:

   ...
   "fingerprint": "utgYE_XWtE8=",
   "items": [
   {
    "key": "ssh-keys",
    "value": "cloudysanfrancisco:ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDAu5kKQCPF...\nbaklavainthebalkans:ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQDQDx3FNVC8... google-ssh {"userName":"baklavainthebalkans","expireOn":"2021-06-14T16:59:03+0000"}"
   }
   ]
   ...
   

2. Add the new ssh-keys value by using the projects.setCommonInstanceMetadata method.

   POST https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/setCommonInstanceMetadata
   
   {
   "items": [
    {
     "key": "ssh-keys",
     "value": "EXISTING_SSH_KEYS\nNEW_SSH_KEY"
    }
   ]
   "fingerprint": "FINGERPRINT"
   }
   

   Replace the following:

   • PROJECT_ID: your project ID
   • EXISTING_SSH_KEYS: the value of the ssh-keys key from the response of the projects.get request
   • FINGERPRINT: the value of the fingerprint from the response of the projects.get request

   • NEW_SSH_KEY: the new SSH key, in one of the following formats:

     • Format for a key without an expiration time:

       USERNAME:KEY_VALUE

     • Format for a key with an expiration time:

       USERNAME:KEY_VALUE google-ssh {"userName":"USERNAME","expireOn":"EXPIRE_TIME"}

     Replace the following:

     • KEY_VALUE: the public SSH key value
     • USERNAME: your username. For example, cloudysanfrancisco, or cloudysanfrancisco_gmail_com.

       For Linux VMs, the USERNAME can't be root, unless you configure your VM to allow root login. For more information, see Connecting to instances as the root user.

       For Windows VMs that use Active Directory (AD), the username must be prepended with the AD domain, in the format of DOMAIN\. For example, the user cloudysanfrancisco within the ad.example.com AD has a USERNAME of example\cloudysanfrancisco.

     • EXPIRE_TIME: the time the key expires, in ISO 8601 format. For example: 2021-12-04T20:12:00+0000

Add SSH keys to instance metadata

You can add a public SSH key to instance metadata when you create a VM or after you create a VM.

Add SSH keys to instance metadata during VM creation

You can add SSH keys to instance metadata during VM creation, using the Google Cloud console, gcloud CLI, or Compute Engine API.

Console

To create an instance and add a public SSH key to instance metadata at the same time using the Google Cloud console, do the following:

1. In the Google Cloud console, go to the Create an instance page.

   Go to Create an instance

2. To add a public SSH key to instance metadata, do the following:

   1. In the navigation menu, click Security.

   2. Expand the Manage access section.

   3. To disable OS Login, clear the Control VM access through IAM permissions checkbox.

   4. If you want to allow public SSH keys in project metadata to access the instance, clear the Block project-wide SSH keys checkbox.

   5. In the Add manually generated SSH keys section, click Add item.

   6. Add your public key in the text box. The key must be in one of the following formats:

      • Format for a key without an expiration time:

        KEY_VALUE USERNAME

      • Format for a key with an expiration time:

        KEY_VALUE google-ssh {"userName":"USERNAME","expireOn":"EXPIRE_TIME"}

      Replace the following:

      • KEY_VALUE: the public SSH key value
      • USERNAME: your username. For example, cloudysanfrancisco or cloudysanfrancisco_gmail_com.

        For Linux VMs, the USERNAME can't be root, unless you configure your VM to allow root login. For more information, see Connect to Linux VMs as the root user.

        For Windows VMs that use Active Directory (AD), the username must be prepended with the AD domain, in the format of DOMAIN\. For example, the user cloudysanfrancisco within the ad.example.com AD has a USERNAME of example\cloudysanfrancisco.

      • EXPIRE_TIME: the time the key expires, in ISO 8601 format. For example: 2021-12-04T20:12:00+0000

3. Optional: Specify other configuration options. For more information, see Configuration options during instance creation.

4. To create and start the instance, click Create.

gcloud

1. In the Google Cloud console, activate Cloud Shell.

   Activate Cloud Shell

   At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.

2. To create a VM and add a public SSH key to instance metadata at the same time using the gcloud CLI, use the gcloud compute instances create command:

   gcloud compute instances create VM_NAME \
      --metadata=ssh-keys=PUBLIC_KEY
   

   Replace the following:

   • VM_NAME: the name of the new VM

   • PUBLIC_KEY: your public SSH key, in one of the following formats:

     • Format for a key without an expiration time:

       USERNAME:KEY_VALUE

     • Format for a key with an expiration time:

       USERNAME:KEY_VALUE google-ssh {"userName":"USERNAME","expireOn":"EXPIRE_TIME"}

     Replace the following:

     • KEY_VALUE: the public SSH key value
     • USERNAME: your username. For example, cloudysanfrancisco, or cloudysanfrancisco_gmail_com.

       For Linux VMs, the USERNAME can't be root, unless you configure your VM to allow root login. For more information, see Connecting to instances as the root user.

       For Windows VMs that use Active Directory (AD), the username must be prepended with the AD domain, in the format of DOMAIN\. For example, the user cloudysanfrancisco within the ad.example.com AD has a USERNAME of example\cloudysanfrancisco.

     • EXPIRE_TIME: the time the key expires, in ISO 8601 format. For example: 2021-12-04T20:12:00+0000

   You can add multiple SSH keys by using the --metadata-from-file=ssh-keys=FILE_PATH flag. In the file, add a list of usernames and public SSH keys in one of the preceding formats.

Terraform

To add a public SSH key to your instance metadata, use the google_compute_instance resource.

resource "google_compute_instance" "default" {
  name         = "my-vm"
  machine_type = "n1-standard-1"
  zone         = "us-central1-a"

  boot_disk {
    initialize_params {
      image = "ubuntu-1404-trusty-v20160627"
    }
  }

  # Local SSD disk
  scratch_disk {
    interface = "SCSI"
  }

  network_interface {
    network = "default"
    access_config {}
  }
  metadata = {
    "ssh-keys" = <<EOT
      dev:ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILg6UtHDNyMNAh0GjaytsJdrUxjtLy3APXqZfNZhvCeT dev
      test:ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILg6UtHDNyMNAh0GjaytsJdrUxjtLy3APXqZfNZhvCeT test
     EOT
  }
}

REST

To create a VM and add a public SSH key to instance metadata at the same time using the Compute Engine, construct a POST request to the instances.insert method:

POST https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/zones/ZONE/instances

Replace the following:

• PROJECT_ID: the project ID
• ZONE: the zone of the VM

In the body of the request, provide usernames and public SSH keys in the items property:

...
{
 "items": [
    {
     "key": "ssh-keys",
     "value": "PUBLIC_KEY"
    }
   ]
}
...

Replace PUBLIC_KEY with your public key, in one of the following formats:

• Format for a key without an expiration time:

  USERNAME:KEY_VALUE

• Format for a key with an expiration time:

  USERNAME:KEY_VALUE google-ssh {"userName":"USERNAME","expireOn":"EXPIRE_TIME"}

Replace the following:

• KEY_VALUE: the public SSH key value
• USERNAME: your username. For example, cloudysanfrancisco, or cloudysanfrancisco_gmail_com.

  For Linux VMs, the USERNAME can't be root, unless you configure your VM to allow root login. For more information, see Connecting to instances as the root user.

  For Windows VMs that use Active Directory (AD), the username must be prepended with the AD domain, in the format of DOMAIN\. For example, the user cloudysanfrancisco within the ad.example.com AD has a USERNAME of example\cloudysanfrancisco.

• EXPIRE_TIME: the time the key expires, in ISO 8601 format. For example: 2021-12-04T20:12:00+0000

You can add multiple SSH keys by adding \n between keys.

Add SSH keys to instance metadata after VM creation

You can add SSH keys to instance metadata after VM creation, using the Google Cloud console, gcloud CLI, or Compute Engine API.

Permissions required for this task

To perform this task, you must have the following permissions:

• compute.instances.setMetadata on the VM

Console

To add a public SSH key to instance metadata using the Google Cloud console, do the following:

1. In the Google Cloud console, go to the VM instances page.

   Go to VM Instances

2. Click the name of the VM that you want to add an SSH key for.

3. Click Edit.

4. Under SSH Keys, click Add item.

5. Add your public key into the text box. The key must be in one of the following formats:

   • Format for a key without an expiration time:

     KEY_VALUE USERNAME

   • Format for a key with an expiration time:

     KEY_VALUE google-ssh {"userName":"USERNAME","expireOn":"EXPIRE_TIME"}

   Replace the following:

   • KEY_VALUE: the public SSH key value
   • USERNAME: your username. For example, cloudysanfrancisco or cloudysanfrancisco_gmail_com.

     For Linux VMs, the USERNAME can't be root, unless you configure your VM to allow root login. For more information, see Connect to Linux VMs as the root user.

     For Windows VMs that use Active Directory (AD), the username must be prepended with the AD domain, in the format of DOMAIN\. For example, the user cloudysanfrancisco within the ad.example.com AD has a USERNAME of example\cloudysanfrancisco.

   • EXPIRE_TIME: the time the key expires, in ISO 8601 format. For example: 2021-12-04T20:12:00+0000

6. Click Save.

gcloud

1. In the Google Cloud console, activate Cloud Shell.

   Activate Cloud Shell

   At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.

2. If there are existing SSH keys in instance metadata, you must re-add them to instance metadata every time you add a new SSH key using the gcloud CLI. If you don't re-add your existing keys, adding a new key erases the existing keys.

   To add a public SSH key to instance metadata using the gcloud CLI, do the following:

   1. If your VM already has instance-level public SSH keys, get them from metadata and add them to a new file:

      1. Run the gcloud compute instances describe command to get the metadata for the VM:

         gcloud compute instances describe VM_NAME
         

         Replace VM_NAME with the name of the VM for which you need to add or remove public SSH keys.

         The output is similar to the following:

         ...
         metadata:
         ...
         - key: ssh-keys
          value: |-
            cloudysanfrancisco:ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDAu5kKQCPF...
            baklavainthebalkans:ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQDQDx3FNVC8... google-ssh {"userName":"baklavainthebalkans","expireOn":"2021-06-14T16:59:03+0000"}
         ...
         

      2. Copy the ssh-keys metadata value.

      3. Create and open a new text file on your workstation.

      4. In the file, paste the list of keys that you just copied.

      5. Add your new key at the end of the list, in one of the following formats:

      • Format for a key without an expiration time:

        USERNAME:KEY_VALUE

      • Format for a key with an expiration time:

        USERNAME:KEY_VALUE google-ssh {"userName":"USERNAME","expireOn":"EXPIRE_TIME"}

      Replace the following:

      • KEY_VALUE: the public SSH key value
      • USERNAME: your username. For example, cloudysanfrancisco, or cloudysanfrancisco_gmail_com.

        For Linux VMs, the USERNAME can't be root, unless you configure your VM to allow root login. For more information, see Connecting to instances as the root user.

        For Windows VMs that use Active Directory (AD), the username must be prepended with the AD domain, in the format of DOMAIN\. For example, the user cloudysanfrancisco within the ad.example.com AD has a USERNAME of example\cloudysanfrancisco.

      • EXPIRE_TIME: the time the key expires, in ISO 8601 format. For example: 2021-12-04T20:12:00+0000
      1. Save and close the file.

   2. Run the gcloud compute instances add-metadata command to set the ssh-keys value:

      gcloud compute instances add-metadata VM_NAME --metadata-from-file ssh-keys=KEY_FILE
      

      Replace the following:

      • VM_NAME: the VM you want to add the SSH key for
      • KEY_FILE with one of the following:
      • The path to the file you created in the previous step, if the VM had existing SSH keys
      • The path to your new public SSH key file, if the VM didn't have existing SSH keys

REST

If there are existing SSH keys in instance metadata, you must re-add them to instance metadata every time you add a new SSH key using the Compute Engine API. If you don't re-add your existing keys, adding a new key erases the existing keys.

To add a public SSH key to instance metadata using the Compute Engine API, do the following:

1. Get the fingerprint and ssh-keys values from metadata by using the instances.get method.

   GET https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/zones/ZONE/instances/VM_NAME
   

   Replace the following:

   • PROJECT_ID: your project ID
   • ZONE: the zone of the VM to add an SSH key
   • VM_NAME: the VM you're adding an SSH key for

   The response is similar to the following:

   ...
   "fingerprint": "utgYE_XWtE8=",
   "items": [
   {
    "key": "ssh-keys",
     "value": "cloudysanfrancisco:ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDAu5kKQCPF...\nbaklavainthebalkans:ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQDQDx3FNVC8... google-ssh {"userName":"baklavainthebalkans","expireOn":"2021-06-14T16:59:03+0000"}"
   }
   ]
   ...
   

2. Add the new ssh-keys value by using the instances.setMetadata method.

   POST https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/zones/ZONE/instances/VM_NAME/setMetadata
   
   {
   "items": [
    {
     "key": "ssh-keys",
     "value": "EXISTING_SSH_KEYS\nNEW_SSH_KEY"
    }
   ]
   "fingerprint": "FINGERPRINT"
   }
   

   Replace the following:

   • PROJECT_ID: your project ID
   • EXISTING_SSH_KEYS: the value of the ssh-keys key from the response of the instances.get request
   • FINGERPRINT: the fingerprint from the response of the projects.get request

   • NEW_SSH_KEY: the new SSH key, in one of the following formats:

     • Format for a key without an expiration time:

       USERNAME:KEY_VALUE

     • Format for a key with an expiration time:

       USERNAME:KEY_VALUE google-ssh {"userName":"USERNAME","expireOn":"EXPIRE_TIME"}

     Replace the following:

     • KEY_VALUE: the public SSH key value
     • USERNAME: your username. For example, cloudysanfrancisco, or cloudysanfrancisco_gmail_com.

       For Linux VMs, the USERNAME can't be root, unless you configure your VM to allow root login. For more information, see Connecting to instances as the root user.

       For Windows VMs that use Active Directory (AD), the username must be prepended with the AD domain, in the format of DOMAIN\. For example, the user cloudysanfrancisco within the ad.example.com AD has a USERNAME of example\cloudysanfrancisco.

     • EXPIRE_TIME: the time the key expires, in ISO 8601 format. For example: 2021-12-04T20:12:00+0000

What's next?

• Learn how to connect to VMs.
• Learn how to manage access to VMs.
• Learn how to transfer files to VMs.
• Learn how SSH connections to Linux VMs work on Compute Engine.