Ansible: How to Print Debug Message Result Variable

ansibleansible-playbookdebugvariables

I have a simple task that I cannot overcome.

I have a playbook that returns AWS EC2 instance configuration. I need to only print (display) private_ip_address.

Here my playbook

---
- hosts: local
  connection: local
  gather_facts: false
  become: yes
  become_method: enable

  tasks:

  - name: gather-info-ec2
    community.aws.ec2_instance_info:
      instance_ids:
        - i-XXXXXAAAAAA

    register: ec2

  - debug: msg="{{ ec2.instances.network_interfaces.private_ip_address }}"

When I run it like this, I get the following error.

fatal: [localhost]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'list object' has no attribute 'network_interfaces'\n\nThe error appears to be in '/etc/ansible/playbooks/AWSLinuxMigration/gather_ec2_info.yaml': line 16, column 5, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n  - debug: msg=\"{{ ec2.instances.network_interfaces.private_ip_address }}\"\n    ^ here\nWe could be wrong, but this one looks like it might be an issue with\nmissing quotes. Always quote template expression brackets when they\nstart a value. For instance:\n\n    with_items:\n      - {{ foo }}\n\nShould be written as:\n\n    with_items:\n      - \"{{ foo }}\"\n"}

When I execute it without DEBUG section and with -vvv it displays the below result. How to I extract and print this address? I shortened it a bit, but you get an idea

ok: [localhost] => {
    "msg": {
        "changed": false,
        "failed": false,
        "instances": [
            {
                "ami_launch_index": 0,
                "architecture": "x86_64",
                "block_device_mappings": [
                    {
                        "device_name": "/dev/xvda",
                        "ebs": {
                            "attach_time": "2020-04-15T16:11:19+00:00",
                            "delete_on_termination": true,
                            "status": "attached",
                            "volume_id": "xxxxxx"
                        }
                    }
                ],
                "capacity_reservation_specification": {
                    "capacity_reservation_preference": "open"
                },
                "client_token": "",
                "cpu_options": {
                    "core_count": 1,
                    "threads_per_core": 2
                },
                "ebs_optimized": true,
                "ena_support": true,
                "enclave_options": {
                    "enabled": false
                },
                "hibernation_options": {
                    "configured": false
                },
                "hypervisor": "xen",
                "iam_instance_profile": {
                    "arn": "xxxxxx",
                    "id": "xxxxxx"
                },
                "image_id": "xxxxx",
                "instance_id": "xxxxx",
                "instance_type": "t3.medium",
                "key_name": "xxxxx",
                "launch_time": "2021-04-21T00:01:25+00:00",
                "metadata_options": {
                    "http_endpoint": "enabled",
                    "http_put_response_hop_limit": 1,
                    "http_tokens": "optional",
                    "state": "applied"
                },
                "monitoring": {
                    "state": "disabled"
                },
                "network_interfaces": [
                    {
                        "association": {
                            "ip_owner_id": "xxxx",
                            "public_dns_name": "xxxxx",
                            "public_ip": "xxxx"
                        },
                        "attachment": {
                            "attach_time": "2020-04-15T16:11:18+00:00",
                            "attachment_id": "xxxxx",
                            "delete_on_termination": true,
                            "device_index": 0,
                            "network_card_index": 0,
                            "status": "attached"
                        },
                        "description": "Primary network interface",
                        "groups": [
                            {
                                "group_id": "xxxxx",
                                "group_name": "xxxxx"
                            }
                        ],
                        "interface_type": "interface",
                        "ipv6_addresses": [],
                        "mac_address": "xxxxx",
                        "network_interface_id": "xxxx",
                        "owner_id": "xxxxx",
                        "private_dns_name": "ip-10-0-1-161.ec2.internal",
                        "private_ip_address": "10.0.1.161",
                        "private_ip_addresses": [
                            {
                                "association": {
                                    "ip_owner_id": "xxxxx",
                                    "public_dns_name": "xxxx.compute-1.amazonaws.com",
                                    "public_ip": "2.2.2.2"
                                },
                                "primary": true,
                                "private_dns_name": "ip-333333.ec2.internal",
                                "private_ip_address": "1.1.1.1."
                            }
                        ],
                        "source_dest_check": true,
                        "status": "in-use"

                    }
                ]
        ]
    }
}

Best Answer

Both attributes instances and network_interfaces are lists. Use json_query, e.g.

    - debug:
        msg: "{{ ec2.instances|
                 json_query('[].network_interfaces[].private_ip_address') }}"

The result will be a list too because there might be more network interfaces and more addresses. In your case, you might want to select the first one, e.g.

    - debug:
        msg: "{{ ec2.instances|
                 json_query('[].network_interfaces[].private_ip_address')|
                 first }}"