Can I simplify my PowerShell Azure runbook to gather soon to expire secrets and certs (vs repeating code) from all KV's in subscription and send a formatted table in an e-mail?
The current runbook runs fine with the associated modules configured to the automation account in the subscription but I'm positive there is a much cleaner way to run this and have a formatted email go out to stakeholders periodically.
Param(
[string]$SubscriptionID = "",
[int]$DaysNearExpiration = "30",
[string]$VaultName
)
Get-AzureRmSubscription -SubscriptionId $SubscriptionID | Select-AzureRmSubscription | Format-Table -Autosize
$ExpiredSecrets = @()
$NearExpirationSecrets = @()
#gather all key vaults from subscription
if ($VaultName) {
$KeyVaults = Get-AzureRmKeyVault -VaultName $VaultName
}
else {
$KeyVaults = Get-AzureRmKeyVault
}
#check date which will notify about expiration
$ExpirationDate = (Get-Date (Get-Date).AddDays($DaysNearExpiration) -Format yyyyMMdd)
$CurrentDate = (Get-Date -Format yyyyMMdd)
# iterate across all key vaults in subscription
foreach ($KeyVault in $KeyVaults) {
# gather all secrets in each key vault
$SecretsArray = Get-AzureKeyVaultSecret -VaultName $KeyVault.VaultName
foreach ($secret in $SecretsArray) {
# check if expiration date is set
if ($secret.Expires) {
$secretExpiration = Get-date $secret.Expires -Format yyyyMMdd
# check if expiration date set on secret is before notify expiration date
if ($ExpirationDate -gt $secretExpiration) {
# check if secret did not expire yet but will expire soon
if ($CurrentDate -lt $secretExpiration) {
$NearExpirationSecrets += New-Object PSObject -Property @{
Name = $secret.Name;
Category = 'SecretNearExpiration';
KeyVaultName = $KeyVault.VaultName;
ExpirationDate = $secret.Expires;
}
}
# secret is already expired
else {
$ExpiredSecrets += New-Object PSObject -Property @{
Name = $secret.Name;
Category = 'SecretNearExpiration';
KeyVaultName = $KeyVault.VaultName;
ExpirationDate = $secret.Expires;
}
}
}
}
}
}
Write-Output "Total number of expired secrets: $($ExpiredSecrets.Count)"
$ExpiredSecrets
Write-Output "Total number of secrets near expiration: $($NearExpirationSecrets.Count)"
$NearExpirationSecrets
$ExpiredCertificates = @()
$NearExpirationCertificates = @()
#gather all key vaults from subscription
if ($VaultName) {
$KeyVaults = Get-AzureRmKeyVault -VaultName $VaultName
}
else {
$KeyVaults = Get-AzureRmKeyVault
}
#check date which will notify about expiration
$ExpirationDate = (Get-Date (Get-Date).AddDays($DaysNearExpiration) -Format yyyyMMdd)
$CurrentDate = (Get-Date -Format yyyyMMdd)
# iterate across all key vaults in subscription
foreach ($KeyVault in $KeyVaults) {
# gather all certificates in each key vault
$CertificatesArray = Get-AzureKeyVaultCertificate -VaultName $KeyVault.VaultName
foreach ($Certificate in $CertificatesArray) {
# check if expiration date is set
if ($certificate.Expires) {
$certificateExpiration = Get-date $certificate.Expires -Format yyyyMMdd
# check if expiration date set on certificate is before notify expiration date
if ($ExpirationDate -gt $certificateExpiration) {
# check if secret did not expire yet but will expire soon
if ($CurrentDate -lt $certificateExpiration) {
$NearExpirationCertificates += New-Object PSObject -Property @{
Name = $certificate.Name;
Category = 'CertificateNearExpiration';
KeyVaultName = $KeyVault.VaultName;
ExpirationDate = $certificate.Expires;
}
}
# secret is already expired
else {
$ExpiredCertificates += New-Object PSObject -Property @{
Name = $certificate.Name;
Category = 'CertificateNearExpiration';
KeyVaultName = $KeyVault.VaultName;
ExpirationDate = $certificate.Expires;
}
}
}
}
}
}
Write-Output "Total number of expired certificates: $($ExpiredCertificates.Count)"
$ExpiredCertificates
Write-Output "Total number of certificates near expiration: $($NearExpirationCertificates.Count)"
$NearExpirationCertificates
Here is a possible refactoring (untested):
Param(
[string]$SubscriptionID = "",
[int]$DaysNearExpiration = "30",
[string]$VaultName
)
Get-AzureRmSubscription -SubscriptionId $SubscriptionID | Select-AzureRmSubscription | Format-Table -Autosize
$ExpiredSecrets = [System.Collections.Generic.List[PSCustomObject]] @()
$NearExpirationSecrets = [System.Collections.Generic.List[PSCustomObject]] @()
#gather all key vaults from subscription
$KeyVaultArgs = if( $VaultName ) { @{ VaultName = $VaultName } } else { @{} }
# In PS 7+ you could write:
# $KeyVaultArgs = $VaultName ? @{ VaultName = $VaultName } : @{}
$KeyVaults = Get-AzureRmKeyVault @KeyVaultArgs
#check date which will notify about expiration
$ExpirationDate = (Get-Date (Get-Date).AddDays($DaysNearExpiration) -Format yyyyMMdd)
$CurrentDate = (Get-Date -Format yyyyMMdd)
# iterate across all key vaults in subscription
foreach ($KeyVault in $KeyVaults) {
# gather all secrets in each key vault
$SecretsArray = Get-AzureKeyVaultSecret -VaultName $KeyVault.VaultName | Where-Object Expires
foreach ($secret in $SecretsArray) {
# check if expiration date is set
$secretExpiration = Get-date $secret.Expires -Format yyyyMMdd
# check if expiration date set on secret is before notify expiration date
if ($ExpirationDate -gt $secretExpiration) {
$secret = [PSCustomObject]@{
Name = $secret.Name
Category = 'SecretNearExpiration'
KeyVaultName = $KeyVault.VaultName
ExpirationDate = $secret.Expires
}
# check if secret did not expire yet but will expire soon
if ($CurrentDate -lt $secretExpiration) {
$NearExpirationSecrets.Add( $secret )
}
# secret is already expired
else {
$ExpiredSecrets.Add( $secret )
}
}
}
}
# omitted unmodified code ...
Changes:
[System.Collections.Generic.List[PSCustomObject]] instead of plain array. This is much more efficient when the array can grow large. Powershell recreates a plain array to size +1 whenever operator += is used. A list's internal array will be resized only in multiples of two instead.$KeyVaultArgs = if ... uses conditional assignment to create the parameters as a hashtable and then uses splatting to need only a single call to Get-AzureRmKeyVault.$SecretsArray = Get-AzureKeyVaultSecret -VaultName $KeyVault.VaultName | Where-Object Expires lets us get rid of the if ($secret.Expires) within the foreach, reducing nesting level.$secret = [PSCustomObject]@{ to remove duplicate code from the if/else construct below. Also slightly cleaner syntax than New-Object PSObject.$NearExpirationSecrets.Add( $secret ) and $ExpiredSecrets.Add( $secret ) are required because list doesn't support the += operator.