Switch context for specific reconciler

[dev-matil]

Hello,
I would like to know if it would be reasonable and worth a contribution to allow a controller to set up not only a namespace but also a context so one operator can listen to multiple clusters.

Would you be interested to discuss this?

[csviri]

Hi @dev-matil ,

Fun fact: about 3 years ago when we started the project we started it with multi cluster support, later removed it ( very early stages) :)

But would be interested in your use case. Isn't deploying the operator to every cluster solves your use case?

It can be not trivial to manage service accouts ( and related tokens ) cross cluster.

[csviri]

right, sounds reasonable.

One think to clarify, the relevant namespaces are replicas on those clusters? So the assumption is that, if we have a configuration for on namespaces on a cluster that will be the same on all other "runtime" clusters?

Or the assumption is that this is always cluster scoped operator?

[csviri]

Do I understand correctly that basically what we want to achieve here, is have controllers listening on events from multiple clusters, and do reconciliation for all resources from all clusters (of a certain kind of course) ?

[metacosm]

That's my understanding as well.

[bs-matil]

yes the latter. the namespaces not necessary relate. The control cluster has different ones. The "runtime" clusters will replicated the same namespaces for each cluster added.

Example.

Control Cluster
┌──────────────────────────────┐  Cluster A
│                              │ ┌──────────────────────────────────────────┐
│    Namespace-crds            │ │  Namespace-A            Namespace-B      │
│    ┌──────────────┐      ┌───┼─┤►┌─────────────┐       ┌─────────────┐    │
│    │              │      │   │ │ │             │       │             │    │
│    │ CRD-A        │      │   │ │ │ Deployment  │       │  Deployment │    │
│    │ CRD-B        │      │   │ │ │             │       │             │    │
│    │              │      │   │ │ └─────────────┘       └─────────────┘    │
│    └─────▲────────┘      │   │ │                                          │
│          │               │   │ └──────────────────────────────────────────┘
│          │ Reconcile     │   │
│          │               │   │  Cluster B
│     ┌────┴────────┬──────┘   │  ┌──────────────────────────────────────────┐
│     │             │          │  │  Namespace-A            Namespace-B      │
│     │  Operator   ├──────────┼──┤►┌─────────────┐       ┌─────────────┐    │
│     │             │  Create/ │  │ │             │       │             │    │
│     └─────────────┘  Reconcile  │ │ Deployment  │       │  Deployment │    │
│                              │  │ │             │       │             │    │
│                              │  │ └─────────────┘       └─────────────┘    │
│                              │  │                                          │
└──────────────────────────────┘  └──────────────────────────────────────────┘

[csviri]

make sense,

First of all my personal opinion is that such feature makes sense, on the other hand brings complexity to the core of the framework. I won't even consider this very exotic TBH.

This is also a good topic to discuss on a weekly meeting (maybe today?). @bs-matil if you could join would be perfect (zoom link on the home github page, code to join is 77777 )

So I'm up to creating a prototype, and see how it looks, what are the problem that we possibly not see at this moment, and see how much complexity it brings on the table. But not sure about the timeline, but if you would be able to work on this, with our support that might be an option too.

@bs-matil Could you also create an issue for this please?

[bs-matil]

This is now a Ticket #1308