There is a command group 'az_vm_extension_image'. This group of commands could 'find the available vm extensions for a subscription and region'. The group of commands has global parameter '--debug' which means 'Increase logging verbosity to show all debug logs.'. The group of commands has global parameter '--help -h' which means 'Show this help message and exit.'. The group of commands has global parameter '--only-show-errors' which means 'Only show errors, suppressing warnings.'. The group of commands has global parameter '--output -o' which means 'Output format.'. The group of commands has global parameter '--query' which means 'JMESPath query string. See <a href="http://jmespath.org/">http://jmespath.org/</a> for more information and examples.'. The group of commands has global parameter '--subscription' which means 'Name or ID of subscription. You can configure the default subscription using `az account set -s NAME_OR_ID`.'. The group of commands has global parameter '--verbose' which means 'Increase logging verbosity. Use --debug for full debug logs.'. This group contains a child command 'az_vm_extension_image_list'.The syntax is: az vm extension image list [--latest]
                           [--location]
                           [--name]
                           [--publisher]
                           [--version]. The 1th example of the child command would be to use it to 'list the unique publishers for extensions', the syntax is: az vm extension image list --query "[].publisher" -o tsv | sort -u. The 2th example of the child command would be to use it to 'find extensions with  docker  in the name', the syntax is: az vm extension image list --query "[].name" -o tsv | sort -u | grep Docker. The 3th example of the child command would be to use it to 'list extension names where the publisher name starts with  microsoft azure app', the syntax is: az vm extension image list --query \
    "[?starts_with(publisher, 'Microsoft.Azure.App')].publisher" \
    -o tsv | sort -u | xargs -I{} az vm extension image list-names --publisher {} -l westus. The parameter '--latest' is optional. show the latest version only.. The parameter '--location -l' is optional. image location.. The parameter '--name -n' is optional. image name.. The parameter '--publisher -p' is optional. image publisher name.. The parameter '--version' is optional. extension version.. 