Public/Update-PSCFNStack.ps1
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function Update-PSCFNStack { <# .SYNOPSIS Updates a stack. .DESCRIPTION Updates a stack via creation and application of a changeset. DYNAMIC PARAMETERS Once the -TemplateLocation argument has been suppied on the command line the function reads the template and creates additional command line parameters for each of the entries found in the "Parameters" section of the template. These parameters are named as per each parameter in the template and defaults and validation rules created for them as defined by the template. Thus, if a template parameter has AllowedPattern and AllowedValues properties, the resultant function argument will permit TAB completion of the AllowedValues, assert that you have entered one of these, and for AllowedPattern, the function argument will assert the regular expression. Template parameters with no default that are not specified on the command line will be passed to the stack as Use Previous Value. .PARAMETER StackName Name of the stack to update. .PARAMETER TemplateLocation Location of the template. This may be - Path to a local file - s3:// URL pointing to template in a bucket - https:// URL pointing to template in a bucket .PARAMETER Capabilities If the stack requires IAM capabilities, TAB auctocompletes between the capability types. .PARAMETER Wait If set, wait for stack update to complete before returning. .PARAMETER Force If set, do not ask for confirmation of the changeset before proceeding. .INPUTS System.String You can pipe the stack name or ARN to this function .OUTPUTS System.String ARN of the stack .EXAMPLE Update-PSCFNStack -StackName MyStack -TemplateLocation .\mystack.json -Capabilities CAPABILITY_IAM -Wait -VpcCidr 10.1.0.0/16 Updates an existing stack of the same name or ARN from a local template file and waits for it to complete. This template would have 'VpcCidr' defined within its parameter block A changeset is created and displayed, and you are asked for confirmation befre proceeding. .EXAMPLE Update-PSCFNStack -StackName MyStack -TemplateLocation https://s3-eu-west-1.amazonaws.com/mybucket/mystack.json -Capabilities CAPABILITY_IAM -Wait -VpcCidr 10.1.0.0/16 As per the first example, but with the template located in S3. .EXAMPLE Update-PSCFNStack -StackName MyStack -TemplateLocation s3://mybucket/mystack.json -Capabilities CAPABILITY_IAM -Wait -VpcCidr 10.1.0.0/16 As per the first example, but using an S3 URL. Caveat to this mechanism is that you must have a default region set in the curent shell. The bucket is assumed to be in this region and the stack will also be built in this region. .EXAMPLE Update-PSCFNStack -StackName MyStack -TemplateLocation .\mystack.json -Capabilities CAPABILITY_IAM -Wait -VpcCidr 10.1.0.0/16 -Force As per the first example, but it begins the update without you being asked to confirm the change .NOTES This cmdlet genenerates additional dynamic command line parameters for all parameters found in the Parameters block of the supplied CloudFormation template #> [CmdletBinding()] param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true, Position = 0)] [string]$StackName, [Parameter(Mandatory = $true)] [string]$TemplateLocation, [ValidateSet('CAPABILITY_IAM', 'CAPABILITY_NAMED_IAM')] [string]$Capabilities, [switch]$Wait, [switch]$Force ) DynamicParam { #Create the RuntimeDefinedParameterDictionary New-Object System.Management.Automation.RuntimeDefinedParameterDictionary | New-CredentialDynamicParameters | New-TemplateDynamicParameters -TemplateLocation $TemplateLocation } begin { $stackParameters = Get-CommandLineStackParameters -CallerBoundParameters $PSBoundParameters $credentialArguments = Get-CommonCredentialParameters -CallerBoundParameters $PSBoundParameters } end { try { $stack = Get-CFNStack -StackName $StackName @credentialArguments } catch { throw "Stack $StackName does not exist" } # Add any parameters not present on command line # as Use Previous Value $stack.Parameters | ForEach-Object { if ($stackParameters.ParameterKey -inotcontains $_.ParameterKey) { $stackParameters += $( $p = New-Object Amazon.CloudFormation.Model.Parameter $p.ParameterKey = $_.ParameterKey $p.UsePreviousValue = $true $p ) } } $changesetName = '{0}-{1}' -f [IO.Path]::GetFileNameWithoutExtension($MyInvocation.MyCommand.Module.Name), [int](([datetime]::UtcNow) - (get-date "1/1/1970")).TotalSeconds Write-Host "Creating change set $changesetName" $stackArgs = New-StackOperationArguments -StackName $StackName -TemplateLocation $TemplateLocation -Capabilities $Capabilities -StackParameters $stackParameters $csArn = New-CFNChangeSet -ChangeSetName $changesetName @stackArgs @credentialArguments $cs = Get-CFNChangeSet -ChangeSetName $csArn @credentialArguments while (('CREATE_COMPLETE', 'FAILED') -inotcontains $cs.Status) { Start-Sleep -Seconds 1 $cs = Get-CFNChangeSet -ChangeSetName $csArn @credentialArguments } if ($cs.Status -ieq 'FAILED') { Write-Host -ForegroundColor Red -BackgroundColor Black "Changeset $changesetName failed to create: $($cs.StatusReason)" throw "Changeset failed to create" } Write-Host ($cs.Changes.ResourceChange | Select-Object Action, LogicalResourceId, PhysicalResourceId, ResourceType | Format-Table | Out-String) if (-not $Force) { $choice = $host.ui.PromptForChoice( 'Begin the stack update now?', $null, @( New-Object System.Management.Automation.Host.ChoiceDescription ('&Yes', "Start rebuild now." ) New-Object System.Management.Automation.Host.ChoiceDescription ('&No', 'Abort operation.') ), 0 ) if ($choice -ne 0) { throw "Aborted." } } Write-Host "Updating stack $StackName" $updateStart = [DateTime]::Now $arn = (Get-CFNStack -StackName $StackName @credentialArguments).StackId Start-CFNChangeSet -StackName $StackName -ChangeSetName $changesetName @credentialArguments if ($Wait) { Write-Host "Waiting for update to complete" $stack = Wait-CFNStack -StackName $arn -Timeout ([TimeSpan]::FromMinutes(60).TotalSeconds) -Status @('UPDATE_COMPLETE', 'UPDATE_ROLLBACK_IN_PROGRESS') @credentialArguments if ($stack.StackStatus -like '*ROLLBACK*') { Write-Host -ForegroundColor Red -BackgroundColor Black "Update failed: $arn" Write-Host -ForegroundColor Red -BackgroundColor Black ( Get-StackFailureEvents -StackName $arn -CredentialArguments $credentialArguments | Where-Object { $_.Timestamp -ge $updateStart } | Sort-Object -Descending Timestamp | Out-String ) throw $stack.StackStatusReason } # Emit ARN $arn } else { # Emit ARN $arn } } } |