ansible/jinja extract multiple attributes from complex json return, rejecting specific matches

Question

I'm trying to extract multiple attributes from a complex payload returned from an API call while rejecting members that have a certain value in the 'name' field. Consider the following payload:

{
"npod_volumes": {
    "changed": false,
    "failed": false,
    "volumes": [
        {
            "accessible_by_host_uuids": [
                "9e8ba77c-8e09-4c69-b893-876742f83f34",
                "ad5a5431-17e1-4023-8373-a6cf64cc5151",
                "3333a278-414b-45d1-8972-611115c76f87",
                "1e36d01a-f936-4249-9045-28232bb103e7"
            ],
            "boot": false,
            "creation_time": "2022-01-26T18:25:46",
            "current_owner_host_uuid": "ad5a5431-17e1-4023-8373-a6cf64cc5151",
            "expiration_time": null,
            "lun_uuids": [
                "8cfe80b6-5773-41bd-b175-e6e495ca0023",
                "8e54f045-89dd-462a-bab4-552ed745ed24",
                "136d7028-2b20-41c7-8b30-e104d211242c",
                "4e7aac12-3b29-41c7-b016-36556feea9f1"
            ],
            "name": "VMware_Lenovo_VV7",
            "natural_backup_host_uuid": "9e8ba77c-8e09-4c69-b893-876742f83f34",
            "natural_backup_spu_serial": "xxxxxxxx",
            "natural_owner_host_uuid": "ad5a5431-17e1-4023-8373-a6cf64cc5151",
            "natural_owner_spu_serial": "xxxxxxxx",
            "npod_uuid": "4b60437a-f8dc-4c80-b4b2-51b64b790487",
            "read_only_snapshot": false,
            "size_bytes": 4000000000000,
            "snapshot_parent_uuid": null,
            "snapshot_uuids": null,
            "sync_state": "InSync",
            "uuid": "ed73e3a0-25e2-4672-8048-84ad4468c0d7",
            "wwn": "6f497c2006174fed000ab00000007000"
        },
        {
            "accessible_by_host_uuids": [
                "9e8ba77c-8e09-4c69-b893-876742f83f34",
                "1e36d01a-f936-4249-9045-28232bb103e7",
                "ad5a5431-17e1-4023-8373-a6cf64cc5151",
                "3333a278-414b-45d1-8972-611115c76f87"
            ],
            "boot": false,
            "creation_time": "2022-01-26T18:25:40",
            "current_owner_host_uuid": "9e8ba77c-8e09-4c69-b893-876742f83f34",
            "expiration_time": null,
            "lun_uuids": [
                "49e511b7-2b5f-4727-ac63-de12c4b6eb45",
                "2baba8a4-dd23-4be4-ad9d-47580efa60d2",
                "4ff844d6-c677-4c2a-a2e5-c13a5c062b3c",
                "21e7f0c8-5f1a-438f-b503-e568f3691c01"
            ],
            "name": "VMware_Lenovo_VV4",
            "natural_backup_host_uuid": "ad5a5431-17e1-4023-8373-a6cf64cc5151",
            "natural_backup_spu_serial": "xxxxxxxx",
            "natural_owner_host_uuid": "9e8ba77c-8e09-4c69-b893-876742f83f34",
            "natural_owner_spu_serial": "xxxxxxxx",
            "npod_uuid": "4b60437a-f8dc-4c80-b4b2-51b64b790487",
            "read_only_snapshot": false,
            "size_bytes": 4000000000000,
            "snapshot_parent_uuid": null,
            "snapshot_uuids": null,
            "sync_state": "InSync",
            "uuid": "cc3991e2-5443-4bd0-a75d-3e8341d26282",
            "wwn": "6f497c2006174fed000ab00000004000"
        },
        {
            "accessible_by_host_uuids": [
                "ad5a5431-17e1-4023-8373-a6cf64cc5151"
            ],
            "boot": true,
            "creation_time": "2022-01-26T18:25:46",
            "current_owner_host_uuid": "ad5a5431-17e1-4023-8373-a6cf64cc5151",
            "expiration_time": null,
            "lun_uuids": [
                "d5ce25a9-15d1-4e36-878e-5e645ef0c557"
            ],
            "name": "VMware_Lenovo_server-09.tme.nebulon.com_os",
            "natural_backup_host_uuid": "9e8ba77c-8e09-4c69-b893-876742f83f34",
            "natural_backup_spu_serial": "xxxxxxxx",
            "natural_owner_host_uuid": "ad5a5431-17e1-4023-8373-a6cf64cc5151",
            "natural_owner_spu_serial": "xxxxxxxx",
            "npod_uuid": "4b60437a-f8dc-4c80-b4b2-51b64b790487",
            "read_only_snapshot": false,
            "size_bytes": 20000000000,
            "snapshot_parent_uuid": null,
            "snapshot_uuids": null,
            "sync_state": "InSync",
            "uuid": "bdbce49d-834d-438e-a56d-9c384bc229c0",
            "wwn": "6f497c2006174fed000ab00000000000"
        }
    ]
}

}

From this return, I need to store the "name" and "wwn" fields for each volume. Additionally, I need to reject any volume that contains "_os" in the "name" field.

I can get the information using a json_query, but haven't figured out how to reject the volumes with "_os" in their names using this approach.

- name: Set volume name and WWN
  set_fact:
    volume_pairs: "{{ npod_volumes | json_query(volume_query) }}"
  vars: 
    volume_query: "volumes[].{name: name, wwn: wwn}"
  tags: volumes

This gives the following output which includes the unwanted "VMware_Lenovo_server-09.tme.nebulon.com_os" volume.

ok: [127.0.0.1] => {
"volume_pairs": [
    {
        "name": "VMware_Lenovo_VV7",
        "wwn": "6f497c2006187474000ab00000007000"
    },
    {
        "name": "VMware_Lenovo_VV4",
        "wwn": "6f497c2006187474000ab00000004000"
    },
    {
        "name": "VMware_Lenovo_server-09.tme.nebulon.com_os",
        "wwn": "6f497c2006187474000ab00000000000"
    }
]

}

Thanks in advance for your time and consideration!

score 0 · Answer 1 · answered Jan 27 '22 at 18:12

So I landed on this solution. Using 'rejectattr' I omit all volumes that contain "_os" in the name. Probably could be done in a more elegant way that excludes my needing to use a json query, but it gets the job done.

  - name: Filter out OS volumes
    set_fact:
      shared_volumes: "{{ npod_volumes.volumes | 
                        rejectattr('name', 'contains', '_os') | 
                        sort(attribute='name') | list }}"
    register: result
    tags: volumes  

  # This builds a list of volumes names and their WWNs
  - name: Set volume name and WWN
    set_fact:
      volume_pairs: "{{ shared_volumes | json_query(volume_query) }}"
    vars: 
      volume_query: "[].{name: name, wwn: wwn}"
    tags: volumes



# {
#     "volume_pairs": [
#         {
#             "name": "VMware_Lenovo_VV4",
#             "wwn": "6f497c2006187474000ab00000004000"
#         },
#         {
#             "name": "VMware_Lenovo_VV5",
#             "wwn": "6f497c2006187474000ab00000005000"
#         },
#         {
#             "name": "VMware_Lenovo_VV6",
#             "wwn": "6f497c2006187474000ab00000006000"
#         },
#         {
#             "name": "VMware_Lenovo_VV7",
#             "wwn": "6f497c2006187474000ab00000007000"
#         }
#     ]
# }

In most situation (e.g. later looping on the list of dicts), you most probably can drop the `json_query` step and directly use `shared_volumes` addressing only the needed attributes for each element (`name` and `wwn`). Mind that `json_query` already goes over your entire list to copy the reduced elements in a new variable. Using them in first place is probably better as far as processing resources usage is concerned. — Zeitounator, Jan 27 '22 at 22:55

ansible/jinja extract multiple attributes from complex json return, rejecting specific matches

1 Answers1