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Resource Orchestration Service:Fn::FindInMap

Last Updated:Jun 17, 2026

Fn::FindInMap returns the value that corresponds to keys in a two-level mapping declared in the Mappings section.

Declaration

JSON

{
  "Fn::FindInMap": [
      "MapName",
      "TopLevelKey",
      "SecondLevelKey"
  ]
}

YAML

Syntax for the full function name:

Fn::FindInMap:
  - MapName
  - TopLevelKey
  - SecondLevelKey

Syntax for the short form:

!FindInMap [MapName,TopLevelKey,SecondLevelKey]

Parameters

MapName: the name of a mapping declared in the Mappings section. For more information, see Mappings.
TopLevelKey: the top-level key. The value consists of key-value pairs.
SecondLevelKey: the second-level key. The value is a string or a number.

Return value

The value assigned to SecondLevelKey.

Examples

The following example specifies the ImageId property for a resource named WebServer. It uses regionParam in the Parameters section to specify regions and RegionMap in the Mappings section to map each region to an ImageId. Fn::FindInMap looks up the ImageId in RegionMap based on the specified region.

The MapName parameter is set to RegionMap.
The TopLevelKey parameter is set to the region where the stack is created. In this example, the parameter is determined by using ! Ref regionParam. For more information, see Ref.
The SecondLevelKey parameter is set to the desired architecture. In this example, "32" is used.

YAML

ROSTemplateFormatVersion: '2015-09-01'
Parameters:
  regionParam:
    Description: the region where you want to create the ECS instance
    Type: String
    AllowedValues:
      - hangzhou
      - beijing
Mappings:
  RegionMap:
    hangzhou:
      '32': m-25l0rcfjo
      '64': m-25l0rcfj1
    beijing:
      '32': m-25l0rcfj2
      '64': m-25l0rcfj3
Resources:
  WebServer:
    Type: ALIYUN::ECS::Instance
    Properties:
      ImageId: !FindInMap [RegionMap, !Ref regionParam, "32"]
      InstanceType: ecs.t1.small
      SecurityGroupId: sg-25zwc****
      ZoneId: cn-beijing-b
      Tags:
        - Key: key1
          Value: value1
        - Key: key2
          Value: value2

JSON

{
  "ROSTemplateFormatVersion": "2015-09-01",
  "Parameters": {
    "regionParam": {
      "Description": "the region where you want to create the ECS instance",
      "Type": "String",
      "AllowedValues": [
        "hangzhou",
        "beijing"
      ]
    }
  },
  "Mappings": {
    "RegionMap": {
      "hangzhou": {
        "32": "m-25l0rcfjo",
        "64": "m-25l0rcfj1"
      },
      "beijing": {
        "32": "m-25l0rcfj2",
        "64": "m-25l0rcfj3"
      }
    }
  },
  "Resources": {
    "WebServer": {
      "Type": "ALIYUN::ECS::Instance",
      "Properties": {
        "ImageId": {
          "Fn::FindInMap": [
            "RegionMap",
            {
              "Ref": "regionParam"
            },
            "32"
          ]
        },
        "InstanceType": "ecs.t1.small",
        "SecurityGroupId": "sg-25zwc****",
        "ZoneId": "cn-beijing-b",
        "Tags": [
          {
            "Key": "key1",
            "Value": "value1"
          },
          {
            "Key": "key2",
            "Value": "value2"
          }
        ]
      }
    }
  }
}

Supported functions