Federation

Establishing the federation between clusters A -> B via admiralty

Create a service account in cluster B that you will run under:

kubectl create serviceaccount sa

Create the source in the same namespace:

apiVersion: multicluster.admiralty.io/v1alpha1
kind: Source
metadata:
  name: cluster-a
spec:
  serviceAccountName: sa

In the cluster A we need to create the secret holding credentials to access the cluster B:

apiVersion: v1
data:
  config: <Base64-encoded config file to access the target cluster>
kind: Secret
metadata:
  name: cluster-b
type: Opaque

To create the config file, get the service account token from the corresponding secret. Then use the normal config file to access the cluster, but replace the user section with something similar to:

users:
- name: default
  user:
    token: <Base64-decoded token>

Then we create the Target in cluster A, referencing the secret we just created:

apiVersion: multicluster.admiralty.io/v1alpha1
kind: Target
metadata:
  name: cluster-b
spec:
  kubeconfigSecret:
    name: cluster-b

After that we can label the namespace in cluster A as being federated:

kubectl label ns fed-namespace multicluster-scheduler=enabled

And try running a federated pod by adding the annotation:

apiVersion: v1
kind: Pod
metadata:
  annotations:
    multicluster.admiralty.io/elect: ""
  name: test-pod
spec:
  containers:
  - name: mypod
    image: centos:centos7
    resources:
      limits:
        memory: 100Mi
        cpu: 100m
      requests:
        memory: 100Mi
        cpu: 100m
    command: ["sh", "-c", "echo 'Im a new pod' && sleep infinity"]