Cleanup of Azure Container Reigstry repository to remove unused layers.

AzureContainerRegistryImageCleanup.ps1

# The MIT License
# Copyright 2019 Jakub Vaňák
# Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
# The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

# The procedure will remove all unreferenced layers from a repository hosted in Azure Container Registry.
# !!! Don't use in the case you pull images by manifest digest !!!
# More details here: https://docs.microsoft.com/en-us/azure/container-registry/container-registry-delete

param(
  [Parameter(Mandatory=$true)]
  [String]$acrRepo
)

az acr repository list -n $acrRepo -o tsv | %{ `
  $acrImg = $_
  Write-Host " => Processing image $acrImg"
  az acr repository show-manifests -n $acrRepo --repository $acrImg --query "`"[?!(tags[?'*'])].digest`"" -o tsv | %{ 
    Write-Host " ===> Processing digest $acrImg@$_"
    az acr repository delete --name $acrRepo --image $acrImg@$_ --yes 
  } 
}

The procedure will remove all unreferenced layers from a repository hosted in Azure Container Registry.
More details here: https://docs.microsoft.com/en-us/azure/container-registry/container-registry-delete

To run the script, copy and paste into your ACR CLI. You will need to specify name of the repository. E.g. in the case your repo URI is foo.azurecr.io the parameter value will be foo.

$acrRepo = 'foo'

---

!!! Don't use in the case you pull images by manifest digest !!!