isabella232 / placement

Controller to make placement decisions based on Placement APIs

Placement

With Placement, you can select a set of ManagedClusters from the ManagedClusterSets bound to the placement namespace.

Community, discussion, contribution, and support

Check the CONTRIBUTING Doc for how to contribute to the repo.

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Getting Started

Prerequisites

You have at least one running kubernetes cluster;

Clone this repo

git clone https://github.com/open-cluster-management-io/placement.git
cd placement

Deploy the placement controller

Set environment variables.

export KUBECONFIG=</path/to/kubeconfig>

Build the docker image to run the placement controller.

go install github.com/openshift/imagebuilder/cmd/[email protected]
make images
export IMAGE_NAME=<placement_image_name> # export IMAGE_NAME=quay.io/open-cluster-management/placement:latest

If your are using kind, load image into the kind cluster.

kind load docker-image <placement_image_name> # kind load docker-image quay.io/open-cluster-management/placement:latest

And then deploy placement manager on the cluster.

make deploy-hub

What is next

After a successful deployment, check on the cluster and see the placement controller has been deployed.

kubectl -n open-cluster-management-hub get pods
NAME                                                  READY   STATUS    RESTARTS   AGE
cluster-manager-placement-controller-cf9bbd6c-x9dnd   1/1     Running   0          2m16s

Here is an example.

Create a ManagedClusterSet.

cat <<EOF | kubectl apply -f -
apiVersion: cluster.open-cluster-management.io/v1alpha1
kind: ManagedClusterSet
metadata:
  name: clusterset1
EOF

Create a ManagedCluster and assign it to clusterset clusterset1.

cat <<EOF | kubectl apply -f -
apiVersion: cluster.open-cluster-management.io/v1
kind: ManagedCluster
metadata:
  name: cluster1
  labels:
    cluster.open-cluster-management.io/clusterset: clusterset1
    vendor: OpenShift
spec:
  hubAcceptsClient: true
EOF

Create a ManagedClusterSetBinding to bind the ManagedClusterSet to the default namespace.

cat <<EOF | kubectl apply -f -
apiVersion: cluster.open-cluster-management.io/v1alpha1
kind: ManagedClusterSetBinding
metadata:
  name: clusterset1
  namespace: default
spec:
  clusterSet: clusterset1
EOF

Now create a Placement:

cat <<EOF | kubectl apply -f -
apiVersion: cluster.open-cluster-management.io/v1alpha1
kind: Placement
metadata:
  name: placement1
  namespace: default
spec:
  predicates:
    - requiredClusterSelector:
        labelSelector:
          matchLabels:
            vendor: OpenShift
EOF

Check the PlacementDecision created for this placement. It contains all selected clusters in status.

kubectl get placementdecisions
NAME                    AGE
placement1-decision-1   2m27s

kubectl describe placementdecisions placement1-decision-1
......
Status:
  Decisions:
    Cluster Name:  cluster1
    Reason:
Events:            <none>

Clean up

Undeploy placement controller from the cluster.

make undeploy-hub