github.com/argoproj/argo-cd/v2@v2.10.9/applicationset/examples/clusterDecisionResource/README.md (about)

     1  # How the Cluster Decision Resource generator works for clusterDecisionResource
     2  1. The Cluster Decision Resource generator reads a configurable status format:
     3  ```yaml
     4  status:
     5    clusters:
     6    - name: cluster-01
     7    - name: cluster-02
     8  ```
     9  This is a common status format.  Another format that could be read looks like this:
    10  ```yaml
    11  status:
    12    decisions:
    13    - clusterName: cluster-01
    14      namespace: cluster-01
    15    - clusterName: cluster-02
    16      namespace: cluster-02
    17  ```
    18  2. Any resource that has a list of key / value pairs, where the value matches ArgoCD cluster names can be used.
    19  3. The key / value pairs found in each element of the list will be available to the template. As well, `name` and `server` will still be available to the template.
    20  4. The Service Account used by the ApplicationSet controller must have access to `Get` the resource you want to retrieve the duck type definition from
    21  5. A configMap is used to identify the resource to read status of generated ArgoCD clusters from. You can use multiple resources by creating a ConfigMap for each one in the ArgoCD namespace.
    22  ```yaml
    23  apiVersion: v1
    24  kind: ConfigMap
    25  metadata:
    26    name: my-configmap
    27  data:
    28    apiVersion: group.io/v1
    29    kind: mykinds
    30    statusListKey: clusters
    31    matchKey: name
    32  ```
    33    * `apiVersion`    - This is the apiVersion of your resource
    34    * `kind`          - This is the plural kind of your resource
    35    * `statusListKey` - Default is 'clusters', this is the key found in your resource's status that is a list of ArgoCD clusters.
    36    * `matchKey`      - Is the key name found in the cluster list, `name` and `clusterName` are the keys in the examples above.
    37  
    38  # Applying the example
    39  1. Connect to a cluster with the ApplicationSet controller running
    40  2. Edit the Role for the ApplicationSet service account, and grant it permission to `list` the `placementdecisions` resources, from apiGroups `cluster.open-cluster-management.io/v1alpha1`
    41  ```yaml
    42  - apiGroups:
    43    - "cluster.open-cluster-management.io/v1alpha1"
    44    resources:
    45    - placementdecisions
    46    verbs:
    47    - list
    48  ```
    49  3. Apply the following controller and associated ManagedCluster CRD's:
    50  https://github.com/open-cluster-management/placement
    51  4. Now apply the PlacementDecision and an ApplicationSet:
    52  ```bash
    53  kubectl apply -f ./placementdecision.yaml
    54  kubectl apply -f ./configMap.yaml
    55  kubectl apply -f ./ducktype-example.yaml
    56  ```
    57  5. For now this won't do anything until you create a controller that populates the `Status.Decisions` array.