To improve the stability of DNS resolution in Container Service for Kubernetes (ACK) clusters, we recommend that you update CoreDNS to the latest version. This topic describes how to update CoreDNS.

Background information

The following issues exist in CoreDNS versions earlier than 1.7.0 and may affect the stability of DNS resolution in ACK clusters:

Update methods

Before you update CoreDNS, we recommend that you read CoreDNS release notes and CoreDNS community changelog to learn the update details and notes.

You can update CoreDNS automatically or manually:
  • Automatic update: Navigate to the Add-ons page in the ACK console. If the Upgrade button is displayed next to the CoreDNS component, it indicates that the component can be automatically updated. For more information, see Configure ACK to automatically update CoreDNS.
  • Manual update: Navigate to the Add-ons page in the ACK console. If the Upgrade button is not displayed next to the CoreDNS component, it indicates that the current component version is outdated. This also indicates that the Kubernetes version of your cluster is outdated and discontinued. In this case, you cannot update CoreDNS to the latest version. To resolve this issue, you must update CoreDNS to 1.6.2 and then update the Kubernetes version of your cluster. Then, you can automatically update CoreDNS to the latest version. For more information about how to manually update CoreDNS, see Manually update CoreDNS.