NewRelicPS.Configuration.Policy.psm1

<#
.Synopsis
  Idempotently applies New Relic alert policy configurations
.Description
  Idempotently applies New Relic alert policy configurations
.Example
  Set-NRPolicyConfiguration -APIKey $AdminAPIKey -DefinedPolicies $Config.AlertPolicies
  Uses New Relic APIs to update alert policies to match the policies defined in $Config.AlertPolicies. Any existing policies that are not defined will be removed.
.Parameter APIKey
  Must be an admin user's API Key, not an account-level REST API Key. See more here: https://docs.newrelic.com/docs/apis/get-started/intro-apis/types-new-relic-api-keys
.Parameter DefinedPolicies
  An array of policy objects which define the desired configuration state for New Relic alert policies and conditions
#>

Function Set-NRPolicyConfiguration {
  [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSShouldProcess", '', Justification = "All CMDLets being called have ShouldProcess in place and the preference is passed to them." )]
  [CMDLetBinding(SupportsShouldProcess = $true)]
  Param (
    [Parameter (Mandatory = $true)]
    [string] $APIKey,
    [Parameter (Mandatory = $false)]
    [array] $DefinedPolicies
  )

  [System.Collections.ArrayList]$existingPolicies = @(Get-NRAlertPolicy -APIKey $APIKey)
  Write-Verbose "There are currently $($DefinedPolicies.count) defined policies and $($existingPolicies.count) existing policies."

  Foreach ($policy in $DefinedPolicies) {
    $CurrentConfig = $existingPolicies | Where-Object { $_.name -eq $policy.name }


    If ($CurrentConfig) {

      # Update policy if it already exists but needs a configuration update
      If ($CurrentConfig.incident_preference -ne $policy.incident_preference) {
        Write-Verbose "Updating policy ($policy.name)"
        $policyId = ($existingPolicies | Where-Object { $_.name -eq $policy.name }).id
        Update-NRAlertPolicy -APIKey $APIKey -PolicyId $policyId -Name $policy.name -IncidentPreference $policy.incident_preference -Whatif:$WhatIfPreference | Out-Null

      }

      # Any extra existing policies that are not defined will be removed later
      $existingPolicies.Remove($CurrentConfig)
    }
    Else {
      # Create the policy if it doesn't exist
      Write-Verbose "Creating policy $($policy.name)"
      New-NRAlertPolicy -APIKey $APIKey -Name $policy.name -IncidentPreference $policy.incident_preference -Whatif:$WhatIfPreference | Out-Null
    }
  }

  # Remove any existing policies that are not defined in the configuration
  If ($existingPolicies) {
      Write-Verbose "Removing policy $($policy.name -join (','))"
      $existingPolicies.Id | Remove-NRAlertPolicy -APIKey $APIKey -Whatif:$WhatIfPreference | Out-Null
  }
}