Describes the  user data of an ECS instance.


  • The returned user data is encoded by the means of Base64.
  • If the user data does not exist, a null value is returned.

Request parameters

Name Type Required Description
Action String Yes The name of this interface. Value: DescribeUserdata
RegionId String Yes The region ID of the instance. You can call DescribeRegions View the latest list of Alibaba Cloud regions.
InstanceId String Yes The ID of the specified instance.

Return parameters

Name Type Description
UserData String The user data of the instance, displayed in the Base64 code.
InstanceId String The instance ID.
RegionId String The region ID


Request example
&<Common request parameters> DescribeUserdata
&<Common request parameters>
Response sample

XML format

    <InstanceId> i-instance1</InstanceId>
    <RegionId> cn-shenzhen </RegionId>
JSON format
    "RequestId": "473469C7-AA6F-4DC5-B3DB-A3DC0DE3C83E"
    "UserData": "userdata1"
    "InstanceId": "i-instance1"
    "RegionId": "cn-shenzhen"

Error codes

Error codes specific to this interface are as follows. For more error codes, see API Error Center.

Error code Error message HTTP status code  Note
InvalidRegionId.NotFound The specified RegionId does not exist. 404 The specified RegionId does not exist.
InvalidInstanceId.NotFound The specified InstanceId does not exist. 404 The specified InstanceId does not exist.