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Fn::FindInMap
The intrinsic function Fn::FindInMap returns the value corresponding
to keys into a two-level map declared in the Mappings section.
Declaration
"Fn::FindInMap" : [ "MapName",
"TopLevelKey",
"SecondLevelKey"]
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. It's 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 is 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,
"32"and"64", that correspond to the AMI's architecture.Each of the second-level keys is assigned an appropriate AMI name.
{
...
"Mappings" : {
"RegionMap" : {
"us-east-1" : { "32" : "ami-6411e20d", "64" : "ami-7a11e213" },
"us-west-1" : { "32" : "ami-c9c7978c", "64" : "ami-cfc7978a" },
"eu-west-1" : { "32" : "ami-37c2f643", "64" : "ami-31c2f645" },
"ap-southeast-1" : { "32" : "ami-66f28c34", "64" : "ami-60f28c32" },
"ap-northeast-1" : { "32" : "ami-9c03a89d", "64" : "ami-a003a8a1" }
}
},
"Resources" : {
"myEC2Instance" : {
"Type" : "AWS::EC2::Instance",
"Properties" : {
"ImageId" : { "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "32"]},
"InstanceType" : "m1.small"
}
}
}
}The example template contains an AWS::EC2::Instance resource whose
ImageId property is set by the FindInMap function.
MapNameis set to the map of interest,"RegionMap"in this example.TopLevelKeyis set to the region where the stack is created, which is determined by using the"AWS::Region"pseudo parameter.SecondLevelKeyis set to the desired architecture,"32"for this example.
FindInMap returns the AMI assigned to
FindInMap. For a 32-bit instance in us-east-1,
FindInMap would return "ami-6411e20d".
