Changing an ECS OS (Using an Image with Cloud-Init Installed)

Function

This API is used to change an ECS OS. During the system disk reinstallation using a new image, the data disks of the ECS remain unchanged.

After this API is called, the system uninstalls the system disk, uses the new image to create a system disk, and attaches it to the ECS. In this way, the OS is changed.

Constraints

  • You can only use an image with Cloud-Init or Cloudbase-Init installed.

  • Only a stopped ECS or an ECS on which reinstalling or changing the OS failed supports changing OS.

  • Only an ECS with a system disk supports changing OS.

  • You are not allowed to perform other operations when changing the OS. Otherwise, changing the OS will fail.

URI

POST /v2/{project_id}/cloudservers/{server_id}/changeos

Table 1 describes the parameters in the URI.

Table 1 Parameter description

Parameter

Mandatory

Description

project_id

Yes

Specifies the project ID.

server_id

Yes

Specifies the ECS ID.

Request

Table 2 describes the request parameters.

Table 2 Request parameters

Parameter

Mandatory

Type

Description

os-change

Yes

Object

Changes an ECS OS. For details, see Table 3.

Table 3 os-change field description

Parameter

Mandatory

Type

Description

keyname

Yes

String

Specifies the key pair name.

userid

No

String

Specifies the user ID. When the keyname parameter is being specified, the value of this parameter is used preferentially. If this parameter is left blank, the user ID in the token is used by default.

imageid

Yes

String

Specifies the ID of the new image in UUID format.

You can obtain the image ID from the console or by following the instructions provided in "Querying Images" in Image Management Service API Reference.

metadata

No

Object

Specifies the metadata of the ECS for which the OS is to be changed.

For more information, see Table 4.

Table 4 metadata field description

Parameter

Mandatory

Type

Description

BYOL

No

String

Specifies whether a user has the license of an image.

  • If this parameter is set to true, the license file delivered with the image is used, indicating that BYOL is used.

  • If this parameter is set to a value other than true, BYOL is not used, and the license file provided by the cloud service platform must be used.

The default value is not true, indicating that BYOL is not used.

user_data

No

String

Specifies the user data to be injected to the ECS during the creation. Text and text files can be injected.

Note

  • The content of user_data must be encoded with base64.

  • The maximum size of the content to be injected (before encoding) is 32 KB.

For more details, see "Injecting User Data into ECSs" in Elastic Cloud Server User Guide.

Examples

Before base64 encoding:

  • Linux

    #! /bin/bash
    echo user_test >> /home/user.txt
    
  • Windows

    rem cmd
    echo 111 > c:\aaa.txt
    

After base64 encoding:

  • Linux

    IyEgL2Jpbi9iYXNoDQplY2hvIHVzZXJfdGVzdCAmZ3Q7Jmd0OyAvaG9tZS91c2VyLnR4dA==
    
  • Windows

    cmVtIGNtZAplY2hvIDExMSA+IGM6XGFhYS50eHQ=
    

__system__encrypted

No

String

Specifies encryption in metadata. The value can be 0 (encryption disabled) or 1 (encryption enabled).

If this parameter does not exist, the system disk will not be encrypted by default.

__system__cmkid

No

String

Specifies the CMK ID, which indicates encryption in metadata. This parameter is used with __system__encrypted.

Note

For details about how to obtain the CMK ID, see "Querying the List of CMKs" in Key Management Service API Reference.

Response

See Responses (Task).

Example Request

  • Example URL request

    POST https://{endpoint}/v2/{project_id}/cloudservers/{server_id}/changeos
    
  • Example request 1 (using a password to remotely log in to an ECS with OS changed)

    {
        "os-change": {
    
            "userid": "7e25b1da389f4697a79df3a0e5bd494e",
            "imageid": "e215580f-73ad-429d-b6f2-5433947433b0"
        }
    }
    
  • Example request 2 (using a key to remotely log in to an ECS with OS changed)

    {
        "os-change": {
            "keyname": "KeyPair-350b",
            "userid": "7e25b1da389f4697a79df3a0e5bd494e",
            "imageid": "e215580f-73ad-429d-b6f2-5433947433b0"
        }
    }
    
  • Example request 3 (using a password to remotely log in a full-ECS-image-created ECS with OS changed and system disk encrypted)

    {
        "os-change": {
    
            "userid": "7e25b1da389f4697a79df3a0e5bd494e",
            "imageid": "e215580f-73ad-429d-b6f2-5433947433b0",
            "metadata": {
                  "__system__encrypted": "1",
                  "__system__cmkid": "83cdb52d-9ebf-4469-9cfa-e7b5b80da846"
            }
        }
    }
    

Example Response

See Responses (Task).

{
    "job_id": "70a599e0-31e7-49b7-b260-868f441e862b"
}

Returned Values

See Returned Values for General Requests.

Error Codes

See Error Codes.