Configure the interactive serial console

Bare Metal Solution provides an interactive serial console to access your Bare Metal Solution servers. You can directly run commands and respond to prompts in the serial console. You can use the serial console to perform configuration and troubleshooting tasks. Bare Metal Solution servers use the first serial port (port 1) as the serial console.

The interactive serial console is supported only on servers with TS54 (43.45.00.002) firmware. Make sure you upgrade your server to TS54 firmware before starting. See Before you begin.

Caution: Some organization policy constraints can cause the interactive serial console connection to be rejected by the server. To enable the interactive serial console access, you must remove those organization policy constraints. For more information on these constraints, see Disable VM serial port access (constraints/compute.disableSerialPortAccess) and Disable Global Access to VM Serial Ports (constraints/compute.disableGlobalSerialPortAccess) in Organization policy constraints.

Interactive serial console connections older than 30 days might be forcefully disconnected.

This document describes how to enable and disable interactive serial console access on your servers.

Before you begin

1. Enable the Bare Metal Solution API. See Set up your Google Cloud project to use the Bare Metal Solution API.

2. Grant the appropriate Identity and Access Management (IAM) role to the user. To perform all tasks in this document, you must have either of the following roles:

   • roles/baremetalsolution.admin
   • roles/baremetalsolution.editor

3. Verify that you have the required version of the firmware: TS54 (43.45.00.002) or higher. Follow these steps:

   1. On your Bare Metal Solution server, run the following command:

      sudo dmidecode -s bios-version
      

      If successful, the output shows a BIOS version of 43.45.00.002 or higher, as shown in the following example:

      Version: BIOS_PUR043.45.00.002
      

   2. If the BIOS version is lower than 43.45.00.002, upgrade the firmware for your servers. Contact Customer Care for upgrade assistance.

      Note: We need a 5-day notice to schedule the upgrade. The upgrade requires approximately 10 hours to complete. We can upgrade up to 3 servers concurrently in a 10-hour window.

4. Ensure that the GRand Unified Bootloader (GRUB) file in your OS has the proper configuration to support the serial console. Follow these steps:

   1. Locate the GRUB configuration file in the /etc/default directory.

   2. Verify that the GRUB configuration file contains the following settings:

      GRUB_CMDLINE_LINUX="(append to the existing value) console=tty0 console=ttyS0,115200"
      GRUB_TERMINAL_OUTPUT="console serial"
      GRUB_TERMINAL="console serial"
      GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"
      

      If the file contains these settings, skip the remaining instructions. You can use your GRUB configuration file to access the serial console.

   3. If the GRUB configuration file does not have these settings, add them manually.

   4. Run the grub-mkconfig command to process the changes. For more information, see the GRUB documentation.

   5. Reboot your server.

Enable interactive serial console access

To enable and access the interactive serial console, follow these steps:

1. Enable access to the interactive serial console.
2. Generate an SSH key.
3. Register the SSH key.
4. Connect to the server.

Enable access to the interactive serial console

Before using the interactive serial console, you must enable access to it on your server.

gcloud

To enable access to the interactive serial console, run the gcloud bms instances enable-serial-console command.

gcloud bms instances enable-serial-console SERVER_NAME --project=PROJECT_ID --region=REGION

Replace the following:

• SERVER_NAME: Name of your server.
• PROJECT_ID: Your project ID.
• REGION: Region of your server.

API

To enable access to the interactive serial console, enter your project ID, region, and server name, and issue the following curl command.

curl -v \
-X POST \
-H "Authorization: Bearer $(gcloud auth print-access-token)" \
-H "X-Goog-User-Project: PROJECT_ID" \
-H "Content-Type: application/json" \
"https://baremetalsolution.googleapis.com/v2/projects/PROJECT_ID/locations/REGION/instances/SERVER_NAME:enableInteractiveSerialConsole"

Replace the following:

• PROJECT_ID: Your project ID.
• REGION: Region of your server.
• SERVER_NAME: Name of your server.

Generate an SSH key pair

Generate an SSH key pair to authenticate your access to the serial console. This needs to be done only once per project.

Note: Any project with VPC-SC cannot use a jump host or other VM inside your project.

Run the ssh-keygen command from a jump host VM instance or other internet-connected terminal to create a new SSH key pair.

  ssh-keygen -b 4096 -f SSH_KEY_ID -N 'PASSPHRASE' -t rsa
  

Replace the following:

• SSH_KEY_ID: Root name of your SSH key file used to generate the public and private keys.
• PASSPHRASE: Passphrase to use when accessing your servers through the serial console.

The ssh-keygen command saves your private key to a file called SSH_KEY_ID, and your public key to a file called SSH_KEY_ID.pub in your home directory.

Register the SSH keys

To authenticate your access to the serial console, register the SSH keys in your project. This needs to be done only once per key pair.

gcloud

To register your SSH keys, run the gcloud bms ssh-keys add command.

gcloud bms ssh-keys add SSH_KEY_ID --project=PROJECT_ID --key-file=SSH_KEY_ID.pub

Replace the following:

• SSH_KEY_ID: Root name of your SSH key file used to generate the public and private keys.
• PROJECT_ID: Your project ID.
• REGION: Region of your server.
• SERVER_NAME: Name of your server.

API

To register your SSH keys, enter your project ID, SSH key ID, and public key filename, and issue the following curl command.

curl -v \
-X POST \
-H "Authorization: Bearer $(gcloud auth print-access-token)" \
-H "X-Goog-User-Project: PROJECT_ID" \
-H "Content-Type: application/json" \
"https://baremetalsolution.googleapis.com/v2/projects/PROJECT_ID/locations/global/sshKeys?ssh_key_id=SSH_KEY_ID" \
--data "{\"public_key\": \"$(cat SSH_KEY_ID.pub)\"}"

Replace the following:

• PROJECT_ID: Your project ID.
• SSH_KEY_ID: Root name of your SSH key file used to generate the public and private keys.

To manage the SSH keys in your project, see Manage SSH keys.

Connect to the server

Use SSH to access the interactive serial console. Run the following command:

  ssh -i SSH_KEY_ID -p 9600 PROJECT_ID.REGION.SERVER_NAME.USERNAME.bms=[e-mail]
  

Replace the following:

• SSH_KEY_ID: Root name of your SSH key file used to generate the public and private keys.
• PROJECT_ID: Your project ID.
• REGION: Region of your server.
• SERVER_NAME: Name of your server.
• USERNAME: Username that you use to access the Bare Metal Solution server through the serial console.

When prompted, enter the SSH key passphrase you configured earlier. As needed, press the Enter or Return key to gain access to the interactive serial console.

Disconnect from the interactive serial console

To disconnect from the serial console, follow these steps:

1. Press the ENTER or RETURN key.
2. Type ~. (tilde, followed by a period).

For SAP HANA on Bare Metal Solution, use CTRL + ] q to disconnect from the interactive serial console.

Manage SSH keys

The SSH keys are stored on a per-project basis. You can manage your SSH keys in the following ways:

• List SSH keys
• Delete SSH keys

List SSH keys

You can list the public SSH keys registered in your project.

gcloud

To list the public SSH keys, run the gcloud bms ssh-keys list command.

gcloud bms ssh-keys list --project=PROJECT_ID

Replace the following:

• PROJECT_ID: Your project ID.

API

To list the public SSH keys, enter your project ID and issue the following curl command.

curl -v \
-X GET \
-H "Authorization: Bearer $(gcloud auth print-access-token)" \
-H "X-Goog-User-Project: PROJECT_ID" \
-H "Content-Type: application/json" \
"https://baremetalsolution.googleapis.com/v2/projects/PROJECT_ID/locations/global/sshKeys"

Replace the following:

• PROJECT_ID: Your project ID.

Delete SSH keys

You can delete an SSH key from the list of authorized keys for a project.

gcloud

To delete a public SSH key, run the gcloud bms ssh-keys remove command.

gcloud bms ssh-keys remove SSH_KEY_ID --project=PROJECT_ID

Replace the following:

• SSH_KEY_ID: Root name of your SSH key file used to generate the public and private keys.
• PROJECT_ID: Your project ID.

API

To delete a public SSH key, enter your project ID and SSH key ID, and issue the following curl command.

curl -v \
-X DELETE \
-H "Authorization: Bearer $(gcloud auth print-access-token)" \
-H "X-Goog-User-Project: PROJECT_ID" \
-H "Content-Type: application/json" \
"https://baremetalsolution.googleapis.com/v2/projects/PROJECT_ID/locations/global/sshKeys/SSH_KEY_ID"

Replace the following:

• PROJECT_ID: Your project ID.
• SSH_KEY_ID: Root name of your SSH key file used to generate the public and private keys.

Disable interactive serial console access

Use the following instructions to disable the interactive serial console access on a server.

gcloud

To disable the interactive serial console, run the gcloud bms instances disable-serial-console command.

gcloud bms instances disable-serial-console SERVER_NAME --project=PROJECT_ID --region=REGION

Replace the following:

• SERVER_NAME: Name of your server.
• PROJECT_ID: Your project ID.
• REGION: Region of your server.

API

To disable the interactive serial console, enter your project ID, region, and server name, and issue the following curl command.

curl -v \
-X POST \
-H "Authorization: Bearer $(gcloud auth print-access-token)" \
-H "X-Goog-User-Project: PROJECT_ID" \
-H "Content-Type: application/json" \
"https://baremetalsolution.googleapis.com/v2/projects/PROJECT_ID/locations/REGION/instances/SERVER_NAME:disableInteractiveSerialConsole"

Replace the following:

• PROJECT_ID: Your project ID.
• REGION: Region of your server.
• SERVER_NAME: Name of your server.