Azure ACR automatic cleaning

Question

Hello,

Currently we are configuring Azure ACR and it has some repositories each of repository consists of images.

Images are locked and tagged in incremental by numbers. Every time developers push their code, an image is created in Azure ACR repository.

We need to configure cleaning of this image, but we can't delete everything because there is a chance that image will contain some information needed for development.

1. Is there possibility to monitor used space by repository? - I can see used space on all Azure ACR, but I need to see and repository instead.
2. How could I automate repository image cleaning? - for steps would be (1. unlock image, 2. un-tag image 3. purge image 4. purge is initiated by date) - this probably is not possible from azure UI interface? Azure CLI?
3. How could I identify that I could remove this Image and that would not damage all production environment?
4. Also this should be monitored by used space and make alerting to notify users, that it's time to clean up some space in repo.

Thanks.

Answer 1

@Eduards , thank you for your question.

1. Is there possibility to monitor used space by repository? - I can see used space on all Azure ACR, but I need to see and repository instead.

At the time of writing, there is no out of the box metric for spaced used by an ACR repository granularly. The available metrics in the Container registry standard metrics namespace are:

Metric	Exportable via Diagnostic Settings?	Unit	Aggregation Type	Description	Dimensions
AgentPoolCPUTime	Yes	Seconds	Total	CPU time used by ACR tasks running on dedicated agent pools	None
RunDuration	Yes	Milliseconds	Total	Duration of ACR tasks runs	None
StorageUsed	No	Bytes	Average	Storage used by the container registry. Sum of storage for unique and shared layers, manifest files, and replica copies in all repositories**	Geolocation
SuccessfulPullCount	Yes	Count	Total	Successful pulls of container images and other artifacts from the registry	None
SuccessfulPushCount	Yes	Count	Total	Successful pushes of container images and other artifacts to the registry	None
TotalPullCount	Yes	Count	Total	Total pulls of container images and other artifacts from the registry	None
TotalPushCount	Yes	Count	Total	Total pushes of container images and other artifacts to the registry	None

**Because of layer sharing, registry storage used may be less than the sum of storage for individual repositories. When you delete a repository or tag, you recover only the storage used by manifest files and the unique layers referenced.

For more information please check here.

2. How could I automate repository image cleaning? - for steps would be (1. unlock image, 2. un-tag image 3. purge image 4. purge is initiated by date) - this probably is not possible from azure UI interface? Azure CLI?

Again, there is no out of the box automation mechanism for all of this from Azure. However, you can write your own steps in scripts using Azure CLI. Following are the references:

• Unlock image
• Untag image
• Purge Image

.

3. How could I identify that I could remove this Image and that would not damage all production environment?

Please check out the Recommendations for tagging and versioning container images.

4. Also this should be monitored by used space and make alerting to notify users, that it's time to clean up some space in repo.

From 1. currently, there is no out of the box metric for spaced used by an ACR repository granularly. However, here's an example of how to Send email alert when registry storage used exceeds a value

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Hope this helps.

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