Created
February 17, 2018 13:26
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Builds an AWS CloudFormation mapping for the latest version of an AMI in all accessible regions.
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| <# | |
| .SYNOPSIS | |
| Build a CloudFormation mapping for the latest version of an AMI in all accessible regions. | |
| .DESCRIPTION | |
| Given an AMI search filter, the script enumerates all known regions looking for the newest AMI that matches the criteria | |
| Depending on where you are and your account permissions, some regions will not return a value e.g. China and Gov Cloud. | |
| Ensure you have the latest version of AWSPowerShell if AWS has recently added new regions. | |
| .PARAMETER ImageName | |
| Name of image to search for (may include wildcards). | |
| .PARAMETER Filter | |
| Filter in Amazon filter syntax to more accurately specify an image to search for. | |
| .PARAMETER MappingName | |
| Name of the mapping to generate. | |
| .OUTPUTS | |
| A hashtable of hashtables which can be piped to ConvertTo-Json to get a block of code that can be pasted into a CF template. | |
| If you have installed a YAML converter like https://github.com/cloudbase/powershell-yaml, then the output can also be piped to ConvertTo-Yaml. | |
| Or you can use the result object itself in some other process. | |
| .EXAMPLE | |
| Get-LatestAMI -ImageName 'amzn-ami-vpc-nat-hvm*' -MappingName 'NatAMI' | ConvertTo-Json | |
| Gets the latest Amazon Linux NAT instance AMIs. | |
| .EXAMPLE | |
| Get-LatestAMI -Filter @{'Name' = 'name'; Values = 'amzn-ami-vpc-nat-hvm*'} -MappingName 'NatAMI' | ConvertTo-Json | |
| Gets the latest Amazon Linux NAT instance AMIs using a filter expression. | |
| #> | |
| param | |
| ( | |
| [Parameter(ParameterSetName='ByName', Mandatory=$true)] | |
| [string]$ImageName, | |
| [Parameter(ParameterSetName='ByFilter', Mandatory=$true)] | |
| $Filter, | |
| [Parameter(Mandatory=$true)] | |
| [string]$MappingName | |
| ) | |
| if ($PSCmdLet.ParameterSetName -ieq 'ByName') | |
| { | |
| # Set a filter from the user supplied name | |
| $Filter = @( | |
| @{'Name' = 'name'; Values = $ImageName} | |
| ) | |
| } | |
| # Create hashtable for results. Key: Region name, Value = AMI definition | |
| $regionsHash = @{} | |
| # Iterate all regions. Ensure you have latest AWSPowerShell installed to cover any new regions. | |
| [Amazon.RegionEndpoint]::EnumerableAllRegions.SystemName | | |
| foreach { | |
| $region = $_ | |
| Write-Host -NoNewLine "$region ... " | |
| try | |
| { | |
| # Get newest AMI matching filter condition for this region | |
| $ami = Get-EC2Image -Filter $Filter -Region $region | sort CreationDate -Descending | select -First 1 | |
| if ($ami) | |
| { | |
| # Add the found AMI to the regions hash | |
| $regionsHash.Add($region, @{'AMI' = $ami.ImageId }) | |
| Write-Host -ForegroundColor Green "$($ami.ImageId) ($($ami.Name))" | |
| } | |
| else | |
| { | |
| # Nothing found matching filters | |
| Write-Host -ForegroundColor Yellow "No match" | |
| } | |
| } | |
| catch | |
| { | |
| # Most likely this is a region to which your account doesn't have access, e.g. GovCloud. | |
| Write-Host -ForegroundColor Red $_.Exception.Message | |
| } | |
| } | |
| # Wrap up with the mapping name and emit result | |
| @{$MappingName = $regionsHash } |
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