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ansiblejinja2

Ansible Jinja2: How to get nth value of nested dict?

My Playbook looks like this

- set_fact:
    vcenter_cluster: "{{ cluster_info.clusters.values[cluster_input.user_input] }}"   

- debug:
    var:  vcenter_cluster

The data in cluster_info.clusters looks like this

ok: [localhost] => {
    "cluster_info.clusters": {

        "DMZ": {
            "datacenter": "dc",

        },
        "K8S": {
            "datacenter": "dc",

        },
        "Win": {
            "datacenter": "dc",
        }
    }
}

My goal is to set vcenter_cluster to K8S when cluster_input.user_input is 1.

Solution

  • A minimal example playbook

    ---
- hosts: localhost
  become: false
  gather_facts: false

  vars:

    cluster_info:
      clusters:
        DMZ:
          datacenter: dc
        K8S:
          datacenter: dc
        WIN:
          datacenter: dc

    user_input: 1

  tasks:

  - name: Show
    debug:
      msg: "{{ (cluster_info.clusters | list)[user_input] }}"

    will result in the requested output of

    TASK [Show] ******
ok: [localhost] =>
  msg: K8S

    Please notice that under certain circumstances there might be a difference in where a list index can start counting with, 0 versus 1. As well that Ansible / Python probably will not maintain the order of the dictionary keys.

    Thanks To

    Further Reading

    regarding the order of dictionary keys