auto-remediation-mca.ps1

param(
    [Parameter(Mandatory = $true)]
    [string]$rootManagementGroup
)

# Define the policies to remediate and the appropriate management groups to remediate them in
$policies = @( 'WortellMcaPolicyInitiative' )

#region create a variable to make sure no errors have occurred during the run.
$problemsOccurred = $false
#endregion

#region load functions
# Function to trigger remediation for a single policy
Function Start-PolicyRemediation {
    Param(
        [Parameter(Mandatory = $true)] [string] $managementGroupName,
        [Parameter(Mandatory = $true)] [string] $policyAssignmentName,
        [Parameter(Mandatory = $true)] [string] $polassignId,
        [Parameter(Mandatory = $false)] [string] $policyDefinitionReferenceId
    )
    $guid = New-Guid
    #create remediation for the individual policy
    $uri = "https://management.azure.com/providers/Microsoft.Management/managementGroups/$($managementGroupName)/providers/Microsoft.PolicyInsights/remediations/$($policyName)-$($guid)?api-version=2021-10-01"
    $body = @{
        properties = @{
            policyAssignmentId = "$polassignId"
        }
    }
    if ($policyDefinitionReferenceId) {
        $body.properties.policyDefinitionReferenceId = $policyDefinitionReferenceId
    }
    $body = $body | ConvertTo-Json -Depth 10
    Invoke-AzRestMethod -Uri $uri -Method PUT -Payload $body
}

#Function to get the policy assignments in the management group scope
function Get-PolicyType {
    Param (
        [Parameter(Mandatory = $true)] [string] $managementGroupName,
        [Parameter(Mandatory = $true)] [string] $policyName
    )

    #Validate that the management group exists through the Azure REST API
    $uri = "https://management.azure.com/providers/Microsoft.Management/managementGroups/$($managementGroupName)?api-version=2021-04-01"
    $result = (Invoke-AzRestMethod -Uri $uri -Method GET).Content | ConvertFrom-Json -Depth 100
    if ($result.error) {
        throw "Management group $managementGroupName does not exist, please specify a valid management group name"
    }

    # Getting custom policySetDefinitions
    $uri = "https://management.azure.com/providers/Microsoft.Management/managementGroups/$($managementGroupName)/providers/Microsoft.Authorization/policySetDefinitions?&api-version=2023-04-01"
    $initiatives = (Invoke-AzRestMethod -Uri $uri -Method GET).Content | ConvertFrom-Json -Depth 100

    #Get policy assignments at management group scope
    $assignmentFound = $false
    $uri = "https://management.azure.com/providers/Microsoft.Management/managementGroups/$($managementGroupName)/providers/Microsoft.Authorization/policyAssignments?`$filter=atScope()&api-version=2022-06-01"
    $result = (Invoke-AzRestMethod -Uri $uri -Method GET).Content | ConvertFrom-Json -Depth 100

    #iterate through the policy assignments
    $result.value | ForEach-Object {
        #check if the policy assignment is for the specified policy set definition
        If ($($PSItem.properties.policyDefinitionId) -match "/providers/Microsoft.Authorization/policySetDefinitions/$policyName") {
            # Go to enumerating policy set
            $assignmentFound = $true
            Enumerate-PolicySet -managementGroupName $managementGroupName -policyAssignmentObject $PSItem
        } Elseif ($($PSItem.properties.policyDefinitionId) -match "/providers/Microsoft.Authorization/policyDefinitions/$policyName") {
            # Go to handling individual policy
            $assignmentFound = $true
            Enumerate-Policy -managementGroupName $managementGroupName -policyAssignmentObject $PSItem
        } Else {
            # Getting parent initiative for unassigned individual policies
            If ($initiatives) {
                $parentInitiative = $initiatives.value | Where-Object {($_.properties.policyType -eq 'Custom') -and ($_.properties.metadata -like '*_deployed_by_amba*')} | Where-Object {$_.properties.policyDefinitions.policyDefinitionReferenceId -eq $policyname}

                # Getting the assignment of the parent initiative
                If ($parentInitiative) {
                    If ($($PSItem.properties.policyDefinitionId) -match "/providers/Microsoft.Authorization/policySetDefinitions/$($parentInitiative.name)") {
                        # Invoking policy remediation
                        $assignmentFound = $true
                        Start-PolicyRemediation -managementGroupName $managementGroupName -policyAssignmentName $PSItem.name -polassignId $PSItem.id -policyDefinitionReferenceId $policyName
                    }
                }
            }
        }
    }

    #if no policy assignments were found for the specified policy name, throw an error
    If (!$assignmentFound) {
        throw "No policy assignments found for policy $policyName at management group scope $managementGroupName"
    }
}

# Function to enumerate the policies in the policy set and trigger remediation for each individual policy
function Enumerate-PolicySet {
    param (
        [Parameter(Mandatory = $true)] [string] $managementGroupName,
        [Parameter(Mandatory = $true)] [object] $policyAssignmentObject
    )
    #extract policy assignment information
    $policyAssignmentObject
    $polassignId = $policyAssignmentObject.id
    $name = $policyAssignmentObject.name
    $policySetId = $policyAssignmentObject.properties.policyDefinitionId
    $policySetId
    $psetUri = "https://management.azure.com$($policySetId)?api-version=2021-06-01"
    $policySet = (Invoke-AzRestMethod -Uri $psetUri -Method GET).Content | ConvertFrom-Json -Depth 100
    $policySet
    $policies = $policySet.properties.policyDefinitions
    #iterate through the policies in the policy set
    Foreach ($policy in $policies) {
        $policyDefinitionId = $policy.policyDefinitionId
        $policyDefinitionReferenceId = $policy.policyDefinitionReferenceId
        #trigger remediation for the individual policy
        Start-PolicyRemediation -managementGroupName $managementGroupName -policyAssignmentName $name -polassignId $polassignId -policyDefinitionReferenceId $policyDefinitionReferenceId
    }
}

#Function to get specific information about a policy assignment for a single policy and trigger remediation
function Enumerate-Policy {
    param (
        [Parameter(Mandatory = $true)] [string] $managementGroupName,
        [Parameter(Mandatory = $true)] [object] $policyAssignmentObject
    )
    #extract policy assignment information
    $polassignId = $policyAssignmentObject.id
    $name = $policyAssignmentObject.name
    $policyDefinitionId = $policyAssignmentObject.properties.policyDefinitionId
    Start-PolicyRemediation -managementGroupName $managementGroupName -policyAssignmentName $name -polassignId $polassignId
}
#endregion

#region connect to Azure
Connect-AzAccount -Identity
#endregion

#region run policy remediation

foreach ($policy in $policies) {
    $managementGroupName = $rootManagementGroup

    Write-Host "Processing policy: $policy" -ForegroundColor Cyan
    # If remediating the Alerting-ServiceHealth initiative, we will remediate the ALZ_ServiceHealth_ActionGroups first,
    # wait for 5 minutes and then remediate the entire Alerting-ServiceHealth initiative.
    If ($policy -eq 'Alerting-ServiceHealth') {
        try {
            Get-PolicyType -managementGroupName $managementGroupName -policyName 'ALZ_ServiceHealth_ActionGroups'
        } catch {
            write-error "Policy 'ALZ_ServiceHealth_ActionGroups' not found.`n$_"
            $problemsOccurred = $true
            continue
        }
            
        Write-Host " Waiting for 5 minutes while remediating the 'Deploy Service Health Action Group' policy before continuing." -ForegroundColor Cyan
        Start-Sleep -Seconds 360
        try {
            Get-PolicyType -managementGroupName $managementGroupName -policyName $policy
        } catch {
            write-error "Policy $policy not found.`n$_"
            $problemsOccurred = $true
            continue
        }
    }
    # Otherwise we just remediate everything passed in
    Else {
        write-output "find policy $policy and remediate"
        try {
            Get-PolicyType -managementGroupName $managementGroupName -policyName $policy
        } catch {
            write-error "Policy $policy not found.`n$_"
            $problemsOccurred = $true
            continue
        }
    }
}

if ($problemsOccurred) {
    "One or more policies failed to remediate"
    throw
}
#endregion