ansible - example of getting snapshot_ids from ami_find results for tagging

00_play.yml

---
- hosts: localhost
  gather_facts: False
  connection: local
  # don't need these with the power of jmespath
  #vars:
  #  snapshot_ids: []
  tasks:
    # I'm not actually running ami_find, i just happen to have a json file handy
    - set_fact:
        ami_find_results: "{{ lookup('file', '01_foo.json') | from_json }}"

    - debug:
        var: ami_find_results

    # little bit of json query + with_items
    #- set_fact:
    #    snapshot_ids: "{{ snapshot_ids|union(item|json_query('block_device_mapping.*.snapshot_id')|list) }}"
    #  with_items: "{{ ami_find_results }}"

    # or just use the full power of json_query, which we need to sum at the end to flatten
    # might be able to remove that too if jmespath is tweaked
    # what this is actually doing (see http://jmespath.org/tutorial.html and other docs for full info)
    # []                    - the top level of ami_find_results is a list
    # .block_device_mapping - pretty obvious, access the block_device_mapping key per list item
    # .*                    - wildcard
    # .snapshot_id          - find the snapshot_id
    # sum(start=[]), jinja way of flattening lists. needed because we get a list of snapshot_ids per item in the results
    - set_fact:
        snapshot_ids: "{{ ami_find_results|json_query('[].block_device_mapping.*.snapshot_id')|sum(start=[]) }}"
        
    - debug:
        var: snapshot_ids

01_foo.json

[ 
    {
        "ami_id": "abc123",
        "architecture": "x86_64",
        "block_device_mapping": {
            "/dev/sda1": {
                "delete_on_termination": true,
                "encrypted": true,
                "size": 40,
                "snapshot_id": "snap-abc123",
                "volume_type": "gp2"
            },
            "/dev/sdb": {
                "delete_on_termination": true,
                "encrypted": true,
                "size": 50,
                "snapshot_id": "snap-efg123",
                "volume_type": "gp2"
            },
            "/dev/sdc": {
                "delete_on_termination": true,
                "encrypted": true,
                "size": 50,
                "snapshot_id": "snap-hij123",
                "volume_type": "gp2"
            }
        },
        "description": "redacted",
        "hypervisor": "xen",
        "is_public": false,
        "location": "redacted",
        "name": "redactedl",
        "owner_id": "redacted",
        "platform": null,
        "root_device_name": "/dev/sda1",
        "root_device_type": "ebs",
        "state": "available",
        "tags": {
            "Name": "redacted"
        },
        "virtualization_type": "hvm"
    },
    {
        "ami_id": "efg123",
        "architecture": "x86_64",
        "block_device_mapping": {
            "/dev/sda1": {
                "delete_on_termination": true,
                "encrypted": true,
                "size": 40,
                "snapshot_id": "blahblah",
                "volume_type": "gp2"
            },
            "/dev/sdb": {
                "delete_on_termination": true,
                "encrypted": true,
                "size": 50,
                "snapshot_id": "blahblah123",
                "volume_type": "gp2"
            },
            "/dev/sdc": {
                "delete_on_termination": true,
                "encrypted": true,
                "size": 50,
                "snapshot_id": "blahblah456",
                "volume_type": "gp2"
            },
            "/dev/sdd": {
                "delete_on_termination": true,
                "encrypted": true,
                "size": 8,
                "snapshot_id": "blahblah789",
                "volume_type": "gp2"
            }
        },
        "description": "redacted",
        "hypervisor": "xen",
        "is_public": false,
        "location": "redacted",
        "name": "redacted",
        "owner_id": "redacted",
        "platform": null,
        "root_device_name": "/dev/sda1",
        "root_device_type": "ebs",
        "state": "available",
        "tags": {
            "Name": "redacted"
        },
        "virtualization_type": "hvm"
    }
]

02_output

...

TASK [debug] *******************************************************************************************************************************************************************************************************************************************************************
ok: [localhost] => {
    "snapshot_ids": [
        "snap-efg123",
        "snap-abc123",
        "snap-hij123",
        "blahblah789",
        "blahblah123",
        "blahblah",
        "blahblah456"
    ]
}

PLAY RECAP *********************************************************************************************************************************************************************************************************************************************************************
localhost                  : ok=4    changed=0    unreachable=0    failed=0