CfnIntrinsicFunctions.ps1
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function Use-CfnBase64Function { <# .SYNOPSIS The intrinsic function Fn::Base64 returns the Base64 representation of the input string. This function is typically used to pass encoded data to Amazon EC2 instances by way of the UserData property. .LINK http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-base64.html #> param( [Parameter(Mandatory,Position=0)] [string]$ValueToEncode ) return @{ "Fn::Base64" = $ValueToEncode } } Set-Alias -Name Fn-Base64 -Value Use-CfnBase64Function function Use-CfnFindInMapFunction { <# .SYNOPSIS The intrinsic function Fn::FindInMap returns the value corresponding to keys in a two-level map that is declared in the Template Mappings section. .LINK http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-findinmap.html #> param( [Parameter(Mandatory,Position=0)] [object]$MapName, [Parameter(Mandatory,Position=1)] [object]$TopLevelKey, [Parameter(Mandatory,Position=2)] [object]$SecondLevelKey ) return @{ "Fn::FindInMap" = @( $MapName, $TopLevelKey, $SecondLevelKey ) } } Set-Alias -Name Fn-FindInMap -Value Use-CfnFindInMapFunction function Use-CfnGetAttFunction { <# .SYNOPSIS The intrinsic function Fn::GetAtt returns the value of an attribute from a resource in the template. .LINK http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-getatt.html #> param( [Parameter(Mandatory,Position=0)] [object]$ResourceName, [Parameter(Mandatory,Position=1)] [object]$AttributeName ) return @{ "Fn::GetAtt" = @( $ResourceName, $AttributeName ) } } Set-Alias -Name Fn-GetAtt -Value Use-CfnGetAttFunction function Use-CfnGetAZsFunction { <# .SYNOPSIS The intrinsic function Fn::GetAZs returns an array that lists Availability Zones for a specified region. .DESCRIPTION Because customers have access to different Availability Zones, the intrinsic function Fn::GetAZs enables template authors to write templates that adapt to the calling user's access. That way you don't have to hard-code a full list of Availability Zones for a specified region. Note For the EC2-Classic platform, the Fn::GetAZs function returns all Availability Zones for a region. For the EC2-VPC platform, the Fn::GetAZs function returns only Availability Zones that have a default subnet unless none of the Availability Zones has a default subnet; in that case, all Availability Zones are returned. IAM permissions The permissions that you need in order to use the Fn::GetAZs function depend on the platform in which you're launching Amazon EC2 instances. For both platforms, you need permissions to the Amazon EC2 DescribeAvailabilityZones and DescribeAccountAttributes actions. For EC2-VPC, you also need permissions to the Amazon EC2 DescribeSubnets action. .LINK http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-getavailabilityzones.html #> param( [Parameter(Position=0)] [object]$Region="" ) return @{ "Fn::GetAZs" = $Region } } Set-Alias -Name Fn-GetAZs -Value Use-CfnGetAZsFunction function Use-CfnJoinFunction { <# .SYNOPSIS The intrinsic function Fn::Join appends a set of values into a single value, separated by the specified delimiter. If a delimiter is the empty string, the set of values are concatenated with no delimiter. .LINK http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-join.html #> param( [Parameter(Mandatory,Position=0)] [object]$Delimiter, [Parameter(Mandatory,Position=1)] [array]$Values=@() ) return @{ "Fn::Join" = @( $Delimiter, $Values ) } } Set-Alias -Name Fn-Join -Value Use-CfnJoinFunction function Use-CfnSelectFunction { <# .SYNOPSIS The intrinsic function Fn::Select returns a single object from a list of objects by index. .DESCRIPTION Important Fn::Select does not check for null values or if the index is out of bounds of the array. Both conditions will result in a stack error, so you should be certain that the index you choose is valid, and that the list contains non-null values. .LINK http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-select.html #> param( [Parameter(Mandatory,Position=0)] [object]$Index, [Parameter(Mandatory,Position=1)] [array]$List=@() ) return @{ "Fn::Select" = @( $Index, $List ) } } Set-Alias -Name Fn-Select -Value Use-CfnSelectFunction function Use-CfnRefFunction { <# .SYNOPSIS The intrinsic function Ref returns the value of the specified parameter or resource. .DESCRIPTION * When you specify a parameter's logical name, it returns the value of the parameter. * When you specify a resource's logical name, it returns a value that you can typically use to refer to that resource, such as a physical ID. When you are declaring a resource in a template and you need to specify another template resource by name, you can use the Ref to refer to that other resource. In general, Ref returns the name of the resource. Tip You can also use Ref to add values to Output messages. .LINK http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-ref.html #> param( [Parameter(Mandatory,Position=0)] [string]$LogicalName ) return @{ "Ref" = $LogicalName } } Set-Alias -Name Fn-Ref -Value Use-CfnRefFunction |