Add SSH keys to VMs (original) (raw)

Linux Windows

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

Before you begin

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. After installing the Google Cloud CLI,initialize it 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.
  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.

  1. Install the Google Cloud CLI.
  2. If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.
  3. To initialize the gcloud CLI, run the following command:
    gcloud init
  4. 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.
After installing the Google Cloud CLI,initialize it 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.
For more information, seeAuthenticate 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 theDirectory 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 iscloudysanfrancisco@gmail.com, 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 theDirectory API. If you already have a username configured, Compute Engine uses that username when you add SSH keys.

Permissions required for this task

To perform this task, you must have the followingpermissions:

gcloud

  1. In the Google Cloud console, activate Cloud Shell.
    Activate Cloud Shell
    At the bottom of the Google Cloud console, aCloud 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 thegcloud 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.

REST

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

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

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

Replace the following:

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, seeRemove 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.

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, seeBlock SSH keys from VMs that use metadata-based SSH keys.

Permissions required for this task

To perform this task, you must have the followingpermissions:

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, seeConnect 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 usercloudysanfrancisco within the ad.example.com AD has aUSERNAME of example\cloudysanfrancisco.
    • EXPIRE_TIME: the time the key expires, inISO 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, aCloud 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 thegcloud compute project-info describe commandto 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, seeConnecting 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 usercloudysanfrancisco within the ad.example.com AD has aUSERNAME of example\cloudysanfrancisco.
      * EXPIRE_TIME: the time the key expires, inISO 8601 format. For example: 2021-12-04T20:12:00+0000
      6. Save and close the file.

    2. Run the gcloud compute project-info add-metadatacommand 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.

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 theprojects.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 theprojects.setCommonInstanceMetadatamethod.
    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-keyskey from the response of the projects.get request
    • FINGERPRINT: the value of the fingerprintfrom 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, seeConnecting 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 usercloudysanfrancisco within the ad.example.com AD has aUSERNAME of example\cloudysanfrancisco.
    * EXPIRE_TIME: the time the key expires, inISO 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 metadatawhen you create a VM orafter 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 theControl 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, clickAdd 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, seeConnect 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 usercloudysanfrancisco within the ad.example.com AD has aUSERNAME of example\cloudysanfrancisco.
      • EXPIRE_TIME: the time the key expires, inISO 8601 format. For example: 2021-12-04T20:12:00+0000
  3. Optional: Specify other configuration options. For more information, seeConfiguration 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, aCloud 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 thegcloud 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, seeConnecting 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 usercloudysanfrancisco within the ad.example.com AD has aUSERNAME of example\cloudysanfrancisco.
    * EXPIRE_TIME: the time the key expires, inISO 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.

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 theinstances.insert method:

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

Replace the following:

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

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

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

Replace the following:

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 followingpermissions:

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, seeConnect 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 usercloudysanfrancisco within the ad.example.com AD has aUSERNAME of example\cloudysanfrancisco.
    • EXPIRE_TIME: the time the key expires, inISO 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, aCloud 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 commandto 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, seeConnecting 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 usercloudysanfrancisco within the ad.example.com AD has aUSERNAME of example\cloudysanfrancisco.
      • EXPIRE_TIME: the time the key expires, inISO 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 theinstances.getmethod.
    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 theinstances.setMetadatamethod.
    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-keyskey from the response of the instances.get request
    • FINGERPRINT: the fingerprintfrom 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, seeConnecting 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 usercloudysanfrancisco within the ad.example.com AD has aUSERNAME of example\cloudysanfrancisco.
    * EXPIRE_TIME: the time the key expires, inISO 8601 format. For example: 2021-12-04T20:12:00+0000

What's next?