Setup Valkey (Open Source Redis) Prerequisites in AKS

 Valkey is the open source redis alternative. We have discussed getting AKS instance ready for Valkey in the post "Create AKS Cluster to Setup Valkey Cluster (Open Source Redis)". Let's look at the prerequisites for setting up Valkey.

First step is setting up a namespace for valkey in the AKS cluster.

# Namespace in aks_vnet for Valkey

---

apiVersion: v1

kind: Namespace

metadata:

  name: valkey

  labels:

    shared-gateway-access: "true"

Identifying VM Sizes Available for AKS in a Given Azure Region

 We sometimes come across issues such as shown below while trying to deploy AKS clusters. It could be due to diffrent reasons. One such case is the below one where there is no availability for the VM size in zone 2 in the region but it has availability in other two regions.

performing CreateOrUpdate: unexpected status 400 (400 Bad Request) with response: {

│   "code": "AvailabilityZoneNotSupported",

│   "details": null,

│   "message": "The zone(s) '2' for resource 'vkdefault' is not supported. The supported zones for location 'eastus2' are '1,3'",

│   "subcode": "",

│   "target": "agentPoolProfile.availabilityZone"

│  }

Get Pod Counts via Kubectl in WSL

 It would be usefull to figure out how many pods running in a given AKS cluster sometimes for various diagnostic needs. In this post let's see how we can use kubectl command to get pod count in diffrent combinations.

Below are some examples.

Create AKS Cluster to Setup Valkey Cluster (Open Source Redis)

 Since bitnami redis images have gone commercial now the best open source redis cluster setup option is to use Valkey, which is guranteed to be open source forever. The source code repos for Valkey is here. We have discussed deploying redis cluster on AKS with bitnami in "Setup Redis Cluster with JSON and Search Modules on AKS with Binami Redis Using Custom Image" However, if we want to deploy Valkey/Redis in cluster in AKS and want to access the Valkey/Redis from outside the AKS cluster, we have to setup AKS networking in a way that each pod is allocated with an IP from the Azure virtual network subnet. In this post let's explore how to setup such an AKS cluster correctly.

Why we need pods in AKS to have IPs from virtual network subnet to deploy Valkey?

When we connect to a Valkey/Redis cluster it always provide diffrent IPs of master nodes to client. Therefore, clients need to acess to IPs of Valkey node pods.

We cannot use Azure CNI overlay for this AKS cluster as it would setup internal network CIDR for pod IPs. Such IPs are not visible outside of AKS. Therefore it is not possible use Azure CNI overlay for AKS clsuter, if we are to deploy Valkey clsuter that should be allowed to access outside of AKS.

We can Azure node subnet mode. But this is not ideal as we have to have a large subnet planned to support boith the node needs as well as pods IP requirement.

The best option is to use Azure CNI Pod Subnet, which would be really useful for this need.