Custom networking annotations Innovation Release

When you create or edit a cluster, the Networking setting normally offers Private or Public connectivity, and Hybrid Manager (HM) applies its own default Kubernetes load balancer service annotations for whichever cloud or platform you're deployed on. Custom networking replaces that default behavior: you supply the load balancer service annotations yourself, and HM applies exactly what you provide, without adding any annotations of its own.

Why use custom networking

Custom networking is useful whenever the built-in Private/Public behavior doesn't fit your environment, for example:

• On-premises deployments with MetalLB. Platforms without a native cloud load balancer, such as Red Hat OpenShift or Rancher Kubernetes Engine, rely on MetalLB to hand out routable IP addresses. Custom annotations let you select which MetalLB IP address pool a cluster's load balancer draws from, request a specific address, or share an address across services.
• Disabling Azure Private Link Service (PLS) on private AKS clusters. By default, HM's private networking creates a PLS resource for every load balancer service. Azure enforces a hard limit of 8 PLS per load balancer, so clusters with many services, such as distributed high-availability clusters, can exhaust that quota. Custom annotations let you disable PLS creation and rely on VNet peering for private connectivity instead.
• Any other load-balancer or cloud-provider-specific behavior that HM doesn't configure automatically, such as AWS or GCP annotations for your own network setup.

Requirements

Custom networking must be enabled for your deployment location by your HM administrator. It's available under any load balancer mode other than disabled. See Load balancer controller for the full mapping of modes to available connectivity types. If custom networking isn't enabled for your location, Custom doesn't appear as a connectivity type option.

How it works

When a cluster uses custom networking, HM skips its own cloud-provider annotation logic entirely and applies only the annotation key/value pairs you provide to the cluster's Kubernetes load balancer service. The underlying platform (MetalLB, the Azure cloud controller, or another load balancer controller) then reads those annotations to decide how to provision the service.

Custom networking is available for single-node, high-availability, and distributed high-availability clusters (including witness groups). You can set it independently for a cluster's primary connection and for its read-only connection.

Setting custom annotations

Using the HM console

1. On the Cluster Settings tab (when creating a cluster) or the cluster's Edit page, under Networking, set Connectivity Type to Custom.
2. Select + Add Annotation and enter a Key and Value.
3. Repeat to add as many annotations as you need, then continue configuring your cluster as usual.

Using edbctl

Set networking: custom and list your annotations under serviceAnnotations in the cluster's YAML configuration:

networking: custom
serviceAnnotations:
  - key: metallb.universe.tf/address-pool
    value: "production-pool"

Then create or patch the cluster as usual, for example:

edbctl cluster create -F cluster.yaml -y

You can also set serviceAnnotations under a cluster's readOnlyConnection.configuration to apply custom annotations to the read-only endpoint. See Cluster templates for the full configuration reference.

Examples

Select a MetalLB IP address pool:

Disable Azure Private Link Service: