Do we need to recreate AKS clusters forMS changes

Question

We've received notifications of two changes that Microsoft is making that sounds like we need to rebuild our existing AKS clusters. Specifically I'm talking about the Docker Bridge CIDR field (BV27-N88) and the SKU name and tier changes (BS5H-DZ8). We have two small 3 node clusters that both use the Docker Bridge CIDR field and have the SKU name Basic (automatically filled in when the clusters were created using Terraform). Do we need to rebuild the clusters in order to keep from having issues going forward?

Answer 1

@Christy, Kevin

Thanks for your question. I understand you received these notices from Azure and are concerned about the impact to your AKS clusters.

For Docker Bridge CIDR field please see this explanation from the PM. Key information: There is no action needed other than "when you update your templates or provisioning code (ARM, Bicep, SDK clients, etc.) to use the 2023-04-01 API version, you will need to stop sending this value if you are doing so today."

For AKS SKU parameters (BS5H-DZ8), this is similar. Your clusters will remain functioning, but you will need to update any automation or future deployments via Terraform to use the new values when using API version 2023-02-01 or newer.

I hope this helps clarify. Let me know if you still have questions. I am including the full text from the advisories below for others to reference:

BV27-N88

We've detected that one or more of your subscription(s) are using the Docker Bridge CIDR field in the AKS API. This field is currently ignored by default and not validated, as it was made redundant during our change from Docker to containerD in Kubernetes version 1.19. Starting from April 2023 with the release of the 2023-04-01 AKS API version, the Docker Bridge CIDR field functionality will be removed. However, it will still be supported in all preexisting API versions without new updates. The April API will be fully implemented and available by 26 May 2023.

Required action

We recommend transitioning from the Docker Bridge CIDR field as it's no longer being validated. If you continue using this field in an API version after it is removed (2023-04-01 API version or later), your API request may be rejected. Furthermore, if you update to use one of the Azure SDKs released after April 2023, your code may not compile.

BS5H-DZ8

You're receiving this notice because you use Azure Kubernetes Service (AKS).

As part of our efforts to improve AKS cluster and workload reliability, we're updating AKS pricing tiers. This includes removing the "Basic" parameter in ManagedClusterSKUName and the "Paid" parameter in ManagedClusterSKUTier in Azure API version 2023-02-01, which is a breaking change.

The "Basic" parameter in ManagedClusterSKUName was replaced by "Base". The "Paid" parameter in ManagedClusterSKUTier was replaced by "Standard", which has the uptime SLA enabled by default, plus:

Support for up to 5,000 nodes per cluster.

Improved cluster reliability and resources.

ManagedClusterSKU parameter changes in Azure API versions 2023-01-01 API or earlier

ManagedClusterSKUName: "Basic"

ManagedClusterSKUTier: "Free", "Paid"

ManagedClusterSKU parameter changes in Azure API versions Starting with 2023-02-01 API

ManagedClusterSKUName: "Base"

ManagedClusterSKUTier: "Free", "Standard"

Recommended action

To avoid disrupting your AKS workloads, update any automated scripts, CD pipelines, ARM templates, Terraform, or other third-party tooling that relies on the ManagedClusterSKUName and ManagedClusterSKUTier parameters that use "Basic" or "Paid" to use "Base" or "Standard" when you adopt Azure API version 2023-02-01 or newer.

---

Please don’t forget to "Accept the answer" and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.