Fn::FindInMap
The intrinsic function Fn::FindInMap
returns the value corresponding to keys in
a two-level map that's declared in the Mappings
section.
For more information on enhancements to the Fn::FindInMap
intrinsic function
when using the AWS::LanguageExtensions
transform, see Fn::FindInMap enhancements.
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
]
Note
You can't nest two instances of two functions in short form.
Parameters
- MapName
-
The logical name of a mapping declared in the Mappings section that contains the keys and values.
- TopLevelKey
-
The top-level key name. Its value is a list of key-value pairs.
- SecondLevelKey
-
The second-level key name, which is set to one of the keys from the list assigned to
TopLevelKey
.
Return value:
The value that's assigned to SecondLevelKey
.
Example
The following example shows how to use Fn::FindInMap
for a template with a
Mappings
section that contains a single map, RegionMap
, that
associates AMIs with AWS Regions.
-
The map has 5 top-level keys that correspond to various AWS Regions.
-
Each top-level key is assigned a list with two second level keys,
"HVM64"
and"HVMG2"
, that correspond to the AMI's architecture. -
Each of the second-level keys is assigned an appropriate AMI name.
The example template contains an AWS::EC2::Instance
resource whose
ImageId
property is set by the FindInMap
function.
MapName
is set to the map of interest, "RegionMap"
in this example.
TopLevelKey
is set to the Region where the stack is created, which is determined by using the
"AWS::Region"
pseudo parameter. SecondLevelKey
is set to the desired architecture,
"HVM64"
for this example.
FindInMap
returns the AMI assigned to FindInMap
. For a HVM64
instance in us-east-1, FindInMap
would return
"ami-0ff8a91507f77f867"
.
JSON
{ ... "Mappings" : { "RegionMap" : { "us-east-1" : { "HVM64" : "ami-0ff8a91507f77f867", "HVMG2" : "ami-0a584ac55a7631c0c" }, "us-west-1" : { "HVM64" : "ami-0bdb828fd58c52235", "HVMG2" : "ami-066ee5fd4a9ef77f1" }, "eu-west-1" : { "HVM64" : "ami-047bb4163c506cd98", "HVMG2" : "ami-0a7c483d527806435" }, "ap-southeast-1" : { "HVM64" : "ami-08569b978cc4dfa10", "HVMG2" : "ami-0be9df32ae9f92309" }, "ap-northeast-1" : { "HVM64" : "ami-06cd52961ce9f0d85", "HVMG2" : "ami-053cdd503598e4a9d" } } }, "Resources" : { "myEC2Instance" : { "Type" : "AWS::EC2::Instance", "Properties" : { "ImageId" : { "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "HVM64" ] }, "InstanceType" : "m1.small" } } } }
YAML
Mappings: RegionMap: us-east-1: HVM64: "ami-0ff8a91507f77f867" HVMG2: "ami-0a584ac55a7631c0c" us-west-1: HVM64: "ami-0bdb828fd58c52235" HVMG2: "ami-066ee5fd4a9ef77f1" eu-west-1: HVM64: "ami-047bb4163c506cd98" HVMG2: "ami-31c2f645" ap-southeast-1: HVM64: "ami-08569b978cc4dfa10" HVMG2: "ami-0be9df32ae9f92309" ap-northeast-1: HVM64: "ami-06cd52961ce9f0d85" HVMG2: "ami-053cdd503598e4a9d" Resources: myEC2Instance: Type: "AWS::EC2::Instance" Properties: ImageId: !FindInMap - RegionMap - !Ref 'AWS::Region' - HVM64 InstanceType: m1.small
Supported functions
You can use the following functions in a Fn::FindInMap
function:
-
Fn::FindInMap
-
Ref