Getting information about a VM

Written by

Yandex Cloud

improved by

amatol

Getting information from outside a VM
Getting information from inside a VM
- Google Compute Engine
- Amazon EC2
Setting up metadata service parameters for a VM instance

To get basic information about each VM you created, go to the management console and open the VM page. To get detailed information with user-defined metadata, use the CLI or API.

You can also get basic information and metadata from inside a VM.

Getting information from outside a VM

Management console

CLI

API

On the Virtual machines page in the Compute Cloud section, you can find a list of VMs in the folder and brief information for each of them.

For more information about a certain VM, click the line with its name.

Tabs:

Overview shows general information about the VM, including the IP addresses assigned to it.
Disks provides information about the disks attached to the VM.
File storage provides information about the file storage attached.
Operations lists operations on the VM and resources attached to it, such as disks.
Monitoring shows information about resource consumption on the VM. You can only get this information from the management console or from inside the VM.
Serial console provides access to the serial console if enabled when creating the VM.
Serial port provides information that the VM outputs to the serial port. To get this information via the API or CLI, follow the Getting serial port's output guide.

The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name or --folder-id parameter.

View a description of the command to get serial port output:
```
yc compute instance get --help
```

Select a VM, such as first-instance:

yc compute instance list

Result:

+----------------------+-----------------+---------------+---------+----------------------+
|          ID          |       NAME      |    ZONE ID    | STATUS  |     DESCRIPTION      |
+----------------------+-----------------+---------------+---------+----------------------+
| fhm0b28lgfp4tkoa3jl6 | first-instance  | ru-central1-a | RUNNING | my first vm via CLI  |
| fhm9gk85nj7gcoji2f8s | second-instance | ru-central1-a | RUNNING | my second vm via CLI |
+----------------------+-----------------+---------------+---------+----------------------+

Get basic information about the VM:
```
yc compute instance get first-instance
```
To get VM information with metadata, use the --full flag:
```
yc compute instance get --full first-instance
```

To get basic information about a VM, use the get REST API method for the Instance resource or the InstanceService/Get gRPC API call.

The basic information does not include the user-defined metadata provided when creating or updating the VM. To get the information along with the metadata, specify view=FULL in the parameters.

Getting information from inside a VM

From inside the VM, the metadata service is accessible at the IP address 169.254.169.254.

Currently, the Yandex Cloud metadata service returns metadata in Google Compute Engine and Amazon EC2 formats.

Google Compute Engine

The Yandex Cloud metadata service lets you return metadata in Google Compute Engine format.

HTTP request

GET http://169.254.169.254/computeMetadata/v1/instance/
  ? alt=<json|text>
  & recursive=<true|false>
  & wait_for_change=<true|false>
  & last_etag=<string>
  & timeout_sec=<int>
Metadata-Flavor: Google

Where:

alt: Response format (by default, text).
recursive: If true, it returns all values in the tree recursively. By default, false.
wait_for_change: If true, this response is only returned when one of the metadata parameters is modified. By default, false.
last_etag: The ETag value from the previous response to a similar request. Use it when wait_for_change="true".
timeout_sec: Maximum request timeout. Use it when wait_for_change="true".

Request examples

Find out the ID of a VM from inside it:

curl -H Metadata-Flavor:Google 169.254.169.254/computeMetadata/v1/instance/id

Get metadata in JSON format:

curl -H Metadata-Flavor:Google 169.254.169.254/computeMetadata/v1/instance/?recursive=true

Get metadata in an easy-to-read format. Use the jq utility:

curl -H Metadata-Flavor:Google 169.254.169.254/computeMetadata/v1/instance/?recursive=true | jq -r '.'

List of returned elements

List of elements available for this request:

attributes/: User-defined metadata provided in the metadata field when creating or updating the VM.
attributes/ssh-keys: List of public SSH keys provided in the metadata field through the ssh-keys value when creating the VM.
description: Text description provided when creating or updating the VM.
disks/: Disks attached to the VM.
hostname: FQDN assigned to the VM.
id: VM ID. The ID is generated automatically when the VM is being created and is unique within Yandex Cloud.
name: Name that was provided when creating or updating the VM.
networkInterfaces/: Network interfaces connected to the VM.
service-accounts: Service accounts linked to the VM.
service-accounts/default/token: Yandex Identity and Access Management token of the linked service account.

Other elements, such as project, which are used for backward compatibility and remain empty.

Amazon EC2

The Yandex Cloud metadata service lets you return metadata in Amazon EC2 format.

This format has no support for user-defined metadata fields.

HTTP request

GET http://169.254.169.254/latest/meta-data/<element>

Where <element> stands for the path to the element you want to get. If the element is omitted, the response returns a list of available elements.

List of returned elements

List of elements that are available for this request.

Note

The angle brackets contain parameters that need to be replaced with values. For example, instead of <mac>, you should insert the MAC address of the network interface.

hostname: VM's hostname.
instance-id: VM ID.
local-ipv4: Internal IPv4 address.
local-hostname: VM's hostname.
mac: MAC address of the VM's network interface.
network/interfaces/macs/<mac>/ipv6s: Internal IPv6 addresses associated with the network interface.
network/interfaces/macs/<mac>/local-hostname: Hostname associated with the network interface.
network/interfaces/macs/<mac>/local-ipv4s: Internal IPv4 addresses associated with the network interface.
network/interfaces/macs/<mac>/mac: MAC address of the VM's network interface.
public-ipv4: External IPv4 address.

Request examples

Getting an internal IP address from inside a VM:

curl http://169.254.169.254/latest/meta-data/local-ipv4

Setting up metadata service parameters for a VM instance

You can set up metadata service parameters when creating or updating VMs.

You can use the following settings:

aws-v1-http-endpoint provides access to metadata using AWS format (IMDSv1). Acceptable values: enabled, disabled.
aws-v1-http-endpoint provides access to Identity and Access Management credentials using AWS format (IMDSv1). Acceptable values: enabled, disabled.

Note

The IMDSv1 format has certain drawbacks in terms of security, which is why the aws-v1-http-token parameter is disabled by default. The most severe drawback of IMDSv1 is its high risk of certain attacks, e.g., SSRF. You can read more about it in the AWS official blog. To change the default behavior of this parameter, contact support.

The safest method to obtain the token in Yandex Cloud is to use Google Compute Engine format, which uses an extra header for protection against SSRF.
gce-http-endpoint provides access to metadata using Google Compute Engine format. Acceptable values: enabled, disabled.
gce-http-token provides access to Identity and Access Management credentials using Google Compute Engine format. Acceptable values: enabled, disabled.

To set up metadata service parameters for a VM instance:

CLI

API

Terraform

If you don't have the Yandex Cloud command line interface yet, install and initialize it.

The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name or --folder-id parameter.

View a description of the CLI command for updating VM parameters:
```
yc compute instance update --help
```
Get a list of VMs in the default folder:
```
yc compute instance list
```
Select the ID or NAME of the relevant VM instance.

Set the metadata service settings using the --metadata-options parameter:

yc compute instance update <VM instance ID> \
  --metadata-options gce-http-endpoint=enabled

Use the update REST API method for the Instance resource or the InstanceService/Update gRPC API call.

For more information about Terraform, see our documentation.

With Terraform, you can quickly create a cloud infrastructure in Yandex Cloud and manage it by configuration files. They store the infrastructure description in HashiCorp Configuration Language (HCL). Terraform and its providers are distributed under the Mozilla Public License.

For more information about the provider resources, see the documentation on the Terraform site or mirror site.

If you change the configuration files, Terraform automatically determines which part of your configuration is already deployed and what should be added or removed.

Open the Terraform configuration file and change the metadata_options parameter in the VM description:
```
...
resource "yandex_compute_instance" "test-vm" {
  metadata_options {
    gce-http-endpoint = "enabled"
  }
}
...
```
For more information about the yandex_compute_instance resource parameters in Terraform, see the provider documentation.
Check the configuration using this command:
```
terraform validate
```
If the configuration is correct, you will get this message:
```
Success! The configuration is valid.
```
Run this command:
```
terraform plan
```
The terminal will display a list of resources with parameters. No changes are made at this step. If the configuration contains any errors, Terraform will point them out.
Apply the configuration changes:
```
terraform apply
```
Confirm the changes: type yes into the terminal and press Enter.

Getting information about a VM

Getting information from outside a VM

Getting information from inside a VM

Google Compute Engine

HTTP request

Request examples

List of returned elements

Amazon EC2

HTTP request

List of returned elements

Request examples

Setting up metadata service parameters for a VM instance

Was the article helpful?