The process to generate a valid CephExternalMultiConfig entry [1] from config-download when deploying storage on the Edge is cumbersome and error prone. 

As per bz 1808424 we can (and should) validate the entry syntactically, but there should also be a tool to generate to generate a yaml file with the necessary entries itself. Producing such a tool should be tracked in this BZ.

The tool would follow the same pattern as the work done for bz 1766711


[1]

  CephExternalMultiConfig:
    - cluster: 'ceph2'
      fsid: 'af25554b-42f6-4d2b-9b9b-d08a1132d3e8'
      external_cluster_mon_ips: '172.18.0.5,172.18.0.6,172.18.0.7'
      keys:
        - name: "client.openstack"
          caps:
            mgr: "allow *"
            mon: "profile rbd"
            osd: "osd: profile rbd pool=volumes, profile rbd pool=backups, profile rbd pool=vms, profile rbd pool=images"
          key: "AQCwmeRcAAAAABAA6SQU/bGqFjlfLro5KxrB1Q=="
          mode: "0600"
      dashboard_enabled: false
    - cluster: 'ceph3'
      fsid: 'e2cba068-5f14-4b0f-b047-acf375c0004a'
      external_cluster_mon_ips: '172.18.0.8,172.18.0.9,172.18.0.10'
      keys:
        - name: "client.openstack"
          caps:
            mgr: "allow *"
            mon: "profile rbd"
            osd: "osd: profile rbd pool=volumes, profile rbd pool=backups, profile rbd pool=vms, profile rbd pool=images"
          key: "AQCwmeRcAAAAABAA6SQU/bGqFjlfLro5KxrB2Q=="
          mode: "0600"
      dashboard_enabled: false