Identify unused managed identity via Azure cli

To identify unused managed identities, you can use the following script:

$identities = az identity list --query "[?type=='SystemAssigned']. [name], [?type=='UserAssigned']. [name]" -o tsv

$unusedIdentities = @ ()

foreach ($identity in $identities) {
$resourceGroup = (az resource show --name $identity --query "resourceGroup" -o tsv)
$date = (az resource show --name $identity --query "properties.creationTime" -o tsv)

if (! $resourceGroup -or (New-TimeSpan -Start $date). Days -gt 30) {
$unusedIdentities += $identity
}
}

$unusedIdentities

This script lists all managed identities that have not been used in the last 30 days. You can modify the number of days as per your requirement. The script first lists all managed identities and then loops through each identity to check if it has been used in the last 30 days. If not, it adds the identity to the list of unused identities.

Removing Unused Managed Identities
Once you have identified unused managed identities, you can remove them using the following commands:

System-assigned managed identity: To remove a system-assigned managed identity, you can simply delete the resource that the identity is assigned to. The identity will be deleted automatically.
User-assigned managed identity: To remove a user-assigned managed identity, you can use the following command:

az identity delete –name

Managed identities in Azure provide an easy way to manage identity and access for applications running on Azure services.
Azure CLI can be used to list all managed identities and identify unused managed identities.
Unused managed identities can be removed to reduce clutter and manage costs.
References
Managed identities for Azure resources overview
az identity – List managed identities
az resource – Show resource details
az identity – Delete a managed identity

https://devcodef1.com/news/1459599/identify-unused-managed-identity