Help Center/ Bare Metal Server/ User Guide/ Instance/ User Data and Metadata/ Retrieving Metadata
Updated on 2023-08-04 GMT+08:00
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Retrieving Metadata

Introduction

The BMS metadata includes BMS basic information on the cloud platform, such as the BMS ID, hostname, and network information. The BMS metadata can be retrieved using compatible OpenStack and EC2 APIs listed in Table 1.

Table 1 BMS metadata types

Metadata Type

Metadata Item

Description

OpenStack type

/meta_data.json

This interface is used to query BMS metadata.

For the key fields in the BMS metadata, see Table 2.

/password

This interface is used to query the BMS password.

If a key pair is selected during the creation of a Windows BMS, Cloudbase-Init is used to save the ciphertext password when the BMS is initialized.

/user_data

This interface is used to query BMS user data.

This metadata allows you to specify scripts and configuration files for initializing BMSs. For details, see Injecting User Data.

For password-authenticated Linux BMSs, save the password injection script.

/network_data.json

This interface is used to query network information of a BMS.

/securitykey

This interface is used to obtain temporary security credentials: Access Key ID (AK) and Secret Access Key (SK).

Before obtaining temporary AK/SK on a BMS, you need to create an agency for BMS on IAM and assign required resource permissions to BMS.

EC2 type

/meta-data/hostname

This interface is used to query the host name of a BMS.

To remove the suffix .novalocal from a BMS, see:

Is the BMS Host Name with Suffix novalocal Normal?

/meta-data/instance-type

This interface is used to query the flavor name of a BMS.

/meta-data/local-ipv4

This interface is used to query the fixed IP address of a BMS.

If there are multiple NICs, only the IP address of the primary NIC is displayed.

/meta-data/placement/availability-zone

This interface is used to query AZ information about a BMS.

/meta-data/public-ipv4

This interface is used to query the EIP of a BMS.

If there are multiple NICs, only the EIP of the primary NIC is displayed.

/meta-data/public-keys/0/openssh-key

This interface is used to query the public key of a BMS.

/user-data

This interface is used to query BMS user data.

/meta-data/security-groups

This interface is used to query the name of the security group of the BMS.
Table 2 Metadata key fields

Parameter

Type

Description

uuid

String

Specifies the BMS ID.

availability_zone

String

Specifies the AZ where the BMS is located.

meta

Dict

Specifies the metadata information, including the image name, image ID, and VPC ID.

hostname

String

Specifies the hostname of the BMS.

To remove the suffix .novalocal from a BMS, see:

Is the BMS Host Name with Suffix novalocal Normal?

vpc_id

String

Specifies the ID of the VPC where the BMS is located.

The following describes the URI and methods of using the supported BMS metadata.

Prerequisites

  • You have logged in to the BMS.
  • Security group rules in the outbound direction meet the following requirements:
    • Protocol: TCP
    • Port Range: 80
    • Remote End: 169.254.0.0/16

    If you use the default security group rules in the outbound direction, the preceding requirements are met, and the metadata can be accessed. The default outbound security group rule is as follows:

    • Protocol: Any
    • Port Range: Any
    • Remote End: 0.0.0.0/16

Metadata (OpenStack Metadata API)

This interface is used to query BMS metadata.

  • URI

    /169.254.169.254/openstack/latest/meta_data.json

  • Method

    Supports GET requests.

  • Example

    The following describes how to use the cURL tool to query the BMS metadata:

    curl http://169.254.169.254/openstack/latest/meta_data.json

    {
    "random_seed": "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",
    "uuid": "ca9e8b7c-f2be-4b6d-a639-f10b4d994d04",
    "availability_zone": "lt-test-1c",
    "hostname": "bms-ddd4-l00349281.novalocal",
    "launch_index": 0,
    "meta": {
        "metering.image_id": "3a64bd37-955e-40cd-ab9e-129db56bc05d",
        "metering.imagetype": "gold",
        "metering.resourcespeccode": "physical.s3.small",
        "metering.cloudServiceType": "service.type.ec2",
        "image_name": "CentOS 7.6 64bit",
        "os_bit": "64",
        "vpc_id": "3b6c201f-aeb3-4bce-b841-64756e66cb49",
        "metering.resourcetype": "1",
        "cascaded.instance_extrainfo": "pcibridge:2",
        "os_type": "Linux",
        "charging_mode": "0"
    },
    "project_id": "6e8b0c94265645f39c5abbe63c4113c6",
    "name": "ecs-ddd4-l00349281"
}

User Data (OpenStack Metadata API)

This interface is used to query BMS user data. The value is configured when you create a BMS. It cannot be changed after the configuration.

  • URI

    /169.254.169.254/openstack/latest/user_data

  • Method

    Supports GET requests.

  • Example

    curl http://169.254.169.254/openstack/latest/user_data

    ICAgICAgDQoiQSBjbG91ZCBkb2VzIG5vdCBrbm93IHdoeSBpdCBtb3ZlcyBpbiBqdXN0IHN1Y2ggYSBkaXJlY3Rpb24gYW5kIGF0IHN1Y2ggYSBzcGVlZC4uLkl0IGZlZWxzIGFuIGltcHVsc2lvbi4uLnRoaXMgaXMgdGhlIHBsYWNlIHRvIGdvIG5vdy4gQnV0IHRoZSBza3kga25vd3MgdGhlIHJlYXNvbnMgYW5kIHRoZSBwYXR0ZXJucyBiZWhpbmQgYWxsIGNsb3VkcywgYW5kIHlvdSB3aWxsIGtub3csIHRvbywgd2hlbiB5b3UgbGlmdCB5b3Vyc2VsZiBoaWdoIGVub3VnaCB0byBzZWUgYmV5b25kIGhvcml6b25zLiINCg0KLVJpY2hhcmQgQmFjaA==
    If user data is not injected during BMS creation, the query result is 404.
    Figure 1 404 Not Found

Network Data (OpenStack Metadata API)

This interface is used to query network information of a BMS.

  • URI

    /openstack/latest/network_data.json

  • Method

    Supports GET requests.

  • Example

    curl http://169.254.169.254/openstack/latest/network_data.json

    {
    "services": [{
        "type": "dns",
        "address": "100.125.1.250"
    },
    {
        "type": "dns",
        "address": "100.125.21.250"
    }],
    "networks": [{
        "network_id": "67dc10ce-441f-4592-9a80-cc709f6436e7",
        "type": "ipv4_dhcp",
        "link": "tap68a9272d-71",
        "id": "network0"
    }],
    "links": [{
        "type": "cascading",
        "vif_id": "68a9272d-7152-4ae7-a138-3ef53af669e7",
        "ethernet_mac_address": "fa:16:3e:f7:c1:47",
        "id": "tap68a9272d-71",
        "mtu": null
    }]
}

Security Key (OpenStack Metadata API)

This interface is used to obtain temporary security credentials: Access Key ID (AK) and Secret Access Key (SK).

  • To obtain temporary AK/SK on a BMS, you need to create an agency for BMS on IAM and assign required resource permissions to BMS. For details, see Identity and Access Management User Guide.
  • The temporary AK/SK pair expires an hour later but is updated 10 minutes ahead of the expiration time. During the 10 minutes, both the new and old temporary AK/SK pairs can be used.
  • When using temporary AK/SK, add 'X-Security-Token':securitytoken in the message header. securitytoken is the value returned when a call is made to the API.
  • URI

    /openstack/latest/securitykey

  • Method

    Supports GET requests.

  • Example

    curl http://169.254.169.254/openstack/latest/securitykey

User Data (EC2 Compatible API)

This interface is used to query BMS user data. The value is configured when you create a BMS. It cannot be changed after the configuration.

  • URI

    /169.254.169.254/latest/user-data

  • Method

    Supports GET requests.

  • Example

    curl http://169.254.169.254/latest/user-data

    ICAgICAgDQoiQSBjbG91ZCBkb2VzIG5vdCBrbm93IHdoeSBpdCBtb3ZlcyBpbiBqdXN0IHN1Y2ggYSBkaXJlY3Rpb24gYW5kIGF0IHN1Y2ggYSBzcGVlZC4uLkl0IGZlZWxzIGFuIGltcHVsc2lvbi4uLnRoaXMgaXMgdGhlIHBsYWNlIHRvIGdvIG5vdy4gQnV0IHRoZSBza3kga25vd3MgdGhlIHJlYXNvbnMgYW5kIHRoZSBwYXR0ZXJucyBiZWhpbmQgYWxsIGNsb3VkcywgYW5kIHlvdSB3aWxsIGtub3csIHRvbywgd2hlbiB5b3UgbGlmdCB5b3Vyc2VsZiBoaWdoIGVub3VnaCB0byBzZWUgYmV5b25kIGhvcml6b25zLiINCg0KLVJpY2hhcmQgQmFjaA==

Hostname (EC2 Compatible API)

This interface is used to query the name of the host accommodating a BMS. The .novalocal suffix will be added later.

  • URI

    /169.254.169.254/latest/meta-data/hostname

  • Method

    Supports GET requests.

  • Example

    curl http://169.254.169.254/latest/meta-data/hostname

    bms-test.novalocal

Instance Type (EC2 Compatible API)

This interface is used to query the flavor name of a BMS.

  • URI

    /169.254.169.254/latest/meta-data/instance-type

  • Method

    Supports GET requests.

  • Example

    curl http://169.254.169.254/latest/meta-data/instance-type

    physical.o2.medium

Local IPv4 (EC2 Compatible API)

This interface is used to query the fixed IP address of a BMS. If there are multiple NICs, only the IP address of the primary NIC is displayed.

  • URI

    /169.254.169.254/latest/meta-data/local-ipv4

  • Method

    Supports GET requests.

  • Example

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

    192.1.1.2

Availability Zone (EC2 Compatible API)

This interface is used to query AZ information about a BMS.

  • URI

    /169.254.169.254/latest/meta-data/placement/availability-zone

  • Method

    Supports GET requests.

  • Example

    curl http://169.254.169.254/latest/meta-data/placement/availability-zone

    az1.dc1

Public IPv4 (EC2 Compatible API)

This interface is used to query the EIP of a BMS. If there are multiple NICs, only the EIP of the primary NIC is displayed.

  • URI

    /169.254.169.254/latest/meta-data/public-ipv4

  • Method

    Supports GET requests.

  • Example

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

    46.1.1.2

Public Keys (EC2 Compatible API)

This interface is used to query the public key of a BMS.

  • URI

    /169.254.169.254/latest/meta-data/public-keys/0/openssh-key

  • Method

    Supports GET requests.

  • Example

    curl http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key

    ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDI5Fw5k8Fgzajn1zJwLoV3+wMP+6CyvsSiIc/hioggSnYu/AD0Yqm8vVO0kWlun1rFbdO+QUZKyVr/OPUjQSw4SRh4qsTKf/+eFoWTjplFvd1WCBZzS/WRenxIwR00KkczHSJro763+wYcwKieb4eKRxaQoQvoFgVjLBULXAjH4eKoKTVNtMXAvPP9aMy2SLgsJNtMb9ArfziAiblQynq7UIfLnN3VclzPeiWrqtzjyOp6CPUXnL0lVPTvbLe8sUteBsJZwlL6K4i+Y0lf3ryqnmQgC21yW4Dzu+kwk8FVT2MgWkCwiZd8gQ/+uJzrJFyMfUOBIklOBfuUENIJUhAB Generated-by-Nova
Parent topic: User Data and Metadata