case "${KUBERNETES_CNI:-}" in 

    "calico")
      echo "Installing Calico CNI"
      install_calico "" "$(dirname "$CONFIG")"
      ;;

    "")
      # perfectly fine, we accepted the default KinD CNI
      ;;

    *)
      # we don't know what to do but we've got no CNI, return non-zero
      echo "${KUBERNETES_CNI} is not recognized. Supported options are \"calico\" or do not set the variable to use default."

The details for the deployment & installation of this plugin were pretty much lifted directly from the
[Calico CNI plugin](https://github.com/projectcalico/cni-plugin).

Specifically:

- The CNI installation script is containerized and deployed as a daemonset in k8s.  The relevant calico k8s manifests were used as the model for the istio-cni plugin's manifest:

    logLevel: debug

    # Configuration file to insert istio-cni plugin configuration
    # by default this will be the first file found in the cni-conf-dir
    # Example
    # cniConfFileName: 10-calico.conflist

    # CNI bin and conf dir override settings
    # defaults:
    cniBinDir: "" # Auto-detected based on version; defaults to /opt/cni/bin.
    cniConfDir: /etc/cni/net.d
    cniConfFileName: ""

  name: speaker
  namespace: metallb-system
---
apiVersion: v1
data:
  excludel2.yaml: |
    announcedInterfacesToExclude: ["^docker.*", "^cbr.*", "^dummy.*", "^virbr.*", "^lxcbr.*", "^veth.*", "^lo$", "^cali.*", "^tunl.*", "^flannel.*", "^kube-ipvs.*", "^cni.*", "^nodelocaldns.*"]
kind: ConfigMap
metadata:
  name: metallb-excludel2
  namespace: metallb-system
---
apiVersion: v1
kind: Secret
metadata:

* Updates Calico version to v2.6.7 (Fixed a bug where Felix would crash when parsing a NetworkPolicy with a named port. See https://github.com/projectcalico/calico/releases/tag/v2.6.7) ([#59130](https://github.com/kubernetes/kubernetes/pull/59130), [@caseydavenport](https://github.com/caseydavenport))