Automatically copying resources to downstream clusters

warning

This is an experimental feature.

From Fleet v0.14.0 onwards, Fleet supports propagating external resources to downstream clusters.

This simplifies dealing with dependencies of charts, such as values coming from external resources. See also valuesFrom.

How it works

HelmOps support a new downstreamResources field, which can be used to reference resources by kind and name. Those resources must:

• Be either secrets or config maps. No other kinds are currently supported.
• Exist before being referenced from the HelmOp, and live in the same namespace as the HelmOp referencing them.

Example:

apiVersion: fleet.cattle.io/v1alpha1
kind: HelmOp
[...] # metadata
spec:
  helm:
    [...] # Helm options
  downstreamResources:
    - kind: Secret
      name: my-secret
    - kind: ConfigMap
      name: my-config

This instructs the Fleet controller to copy those resources to each targeted downstream cluster, before deploying the workload (in this case specified through a Helm chart) to said downstream cluster.

When a cluster is not targeted anymore, the Fleet agent will delete those resources from the cluster as well. They will remain on the upstream cluster, though.

note

If resources referenced through downstreamResources should stay on downstream clusters even after they are no longer targeted, keepResources should be set to true on the HelmOp.

Limitations

Fleet does not monitor resources referenced by downstreamResources for changes. This means that changes to secrets and config maps referenced for downstream copy will only be applied when a HelmOp is updated.