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kubernetesopenshiftwso2-api-managerkubernetes-pod

Determine if a pod should connect to KeyManager1 or KeyManager2

I am currently trying to create an architecture as shown in the diagram below.

For the first deployment of the pods it's quite simple, as I always have an even number, I put the first half on KeyManager1 and the other half on KeyManager2.

My problem is when a pod needs to be replaced.
I need to be able to determine if the new pod should go on KM1 or KM2.

Ideally, I would like to count the number of connections a KM can have from GW pods. If a KM1 has 3 connections and KM2 has 2 connections, the new GW should connect to KM2.

I really don't see how to do this.

scheme of my achitechture

Edit : I was wrong, when a pod is to be deleted, it is deleted before the new one is created.

Can I put something in the preStop to change the deployment file to use for the replacement?

Something like :

if connected to km1
    use deployment-1
else deployment-2
Solution

  • I finally found a solution to my problem. It's not very "clean" but that's all I found.

    To explain quickly, I created 2 files on a PV. When a pod (GW) is created it will read the files. If the 2 files contain 0 the GW points to KM1 and writes 1 to the file, if there is 1 in the KM1 file and 0 in the KM2 file, the GW points to KM2 and writes 1 to the file. We increment like that alternately. When the pod is deleted I decrement with the preStop.