EC2 Name Mapping

ec2_name_mapping.yml

---
- name: Build list of instance IDs by instance name
  ec2_instance_facts:
    region: "{{ region }}"
    filters:
      "tag:NightlyBackup": "Yes"
#      "tag:Name": "{{ groups['backup'] }}"
  register: ec2_facts

- debug:
    var: ec2_facts

- name: Set fact instances
  set_fact:
    instances: "{{ ec2_facts.instances | map(attribute='instance_id') | list }}"

- name: Map Name
  set_fact:
    map_name: "{{ ec2_facts.instances |  map(attribute='tags.Name') | list  }}"

- debug:
    var: map_name

#- name: Replace undefined
#  set_fact:
#    "{{ item[0] }}": "{{ item[1] }}"
#  when: item[0] == "Undefined"
#  with_together:
#    - "{{ map_name }}"
#    - "{{ instances }}"

- debug:
   var: instances

- meta: end_play

- name: List of instance IDs to be backed up
  debug:
    msg: "{{ item }}"
  loop: "{{ instances }}"

output.json

"ec2_facts": {
        "changed": false,
        "failed": false,
        "instances": [
            {
                "ami_launch_index": 0,
                "architecture": "x86_64",
                "block_device_mappings": [
                    {
                        "device_name": "/dev/sda1",
                        "ebs": {
                            "attach_time": "2018-06-07T23:24:18+00:00",
                            "delete_on_termination": true,
                            "status": "attached",
                            "volume_id": "vol-046b2e520c788971d"
                        }
                    }
                ],
                "client_token": "",
                "ebs_optimized": false,
                "ena_support": true,
                "hypervisor": "xen",
                "iam_instance_profile": {
                    "arn": "arn:aws:iam::229792048549:instance-profile/ec2-s3-full-access",
                    "id": "AIPAID3GG2QMCRY7TOW56"
                },
                "image_id": "ami-43a15f3e",
                "instance_id": "i-0468fc479c884d8b7",
                "instance_type": "t2.medium",
                "key_name": "general_key",
                "launch_time": "2018-07-01T01:48:30+00:00",
                "monitoring": {
                    "state": "disabled"
                },
                "network_interfaces": [
                    {
                        "attachment": {
                            "attach_time": "2018-06-07T23:24:16+00:00",
                            "attachment_id": "eni-attach-4a27dcef",
                            "delete_on_termination": true,
                            "device_index": 0,
                            "status": "attached"
                        },
                        "description": "Primary network interface",
                        "groups": [
                            {
                                "group_id": "sg-99882ad1",
                                "group_name": "sshd"
                            },
                            {
                                "group_id": "sg-fc64c6b4",
                                "group_name": "http+https"
                            }
                        ],
                        "ipv6_addresses": [],
                        "mac_address": "12:e6:a5:c2:d9:8a",
                        "network_interface_id": "eni-117ea387",
                        "owner_id": "229792048549",
                        "private_dns_name": "ip-172-31-95-229.ec2.internal",
                        "private_ip_address": "172.31.95.229",
                        "private_ip_addresses": [
                            {
                                "primary": true,
                                "private_dns_name": "ip-172-31-95-229.ec2.internal",
                                "private_ip_address": "172.31.95.229"
                            }
                        ],
                        "source_dest_check": true,
                        "status": "in-use",
                        "subnet_id": "subnet-66f7984a",
                        "vpc_id": "vpc-bc7408c5"
                    }
                ],
                "placement": {
                    "availability_zone": "us-east-1a",
                    "group_name": "",
                    "tenancy": "default"
                },
                "private_dns_name": "ip-172-31-95-229.ec2.internal",
                "private_ip_address": "172.31.95.229",
                "product_codes": [],
                "public_dns_name": "",
                "root_device_name": "/dev/sda1",
                "root_device_type": "ebs",
                "security_groups": [
                    {
                        "group_id": "sg-99882ad1",
                        "group_name": "sshd"
                    },
                    {
                        "group_id": "sg-fc64c6b4",
                        "group_name": "http+https"
                    }
                ],
                "source_dest_check": true,
                "state": {
                    "code": 80,
                    "name": "stopped"
                },
                "state_reason": {
                    "code": "Client.UserInitiatedShutdown",
                    "message": "Client.UserInitiatedShutdown: User initiated shutdown"
                },
                "state_transition_reason": "User initiated (2018-07-01 01:49:14 GMT)",
                "subnet_id": "subnet-66f7984a",
                "tags": {
                    "Name": "solomon-test-2",
                    "NightlyBackup": "Yes"
                },
                "virtualization_type": "hvm",
                "vpc_id": "vpc-bc7408c5"
            },
            {
                "ami_launch_index": 0,
                "architecture": "x86_64",
                "block_device_mappings": [
                    {
                        "device_name": "/dev/sda1",
                        "ebs": {
                            "attach_time": "2018-06-12T19:45:14+00:00",
                            "delete_on_termination": true,
                            "status": "attached",
                            "volume_id": "vol-0d7fc053396341fbc"
                        }
                    }
                ],
                "client_token": "",
                "ebs_optimized": false,
                "ena_support": true,
                "hypervisor": "xen",
                "iam_instance_profile": {
                    "arn": "arn:aws:iam::229792048549:instance-profile/ec2-s3-full-access",
                    "id": "AIPAID3GG2QMCRY7TOW56"
                },
                "image_id": "ami-43a15f3e",
                "instance_id": "i-04ff7bb389bdf86f0",
                "instance_type": "t2.xlarge",
                "key_name": "general_key",
                "launch_time": "2018-07-01T01:48:31+00:00",
                "monitoring": {
                    "state": "disabled"
                },
                "network_interfaces": [
                    {
                        "attachment": {
                            "attach_time": "2018-06-12T19:45:14+00:00",
                            "attachment_id": "eni-attach-140c66ab",
                            "delete_on_termination": true,
                            "device_index": 0,
                            "status": "attached"
                        },
                        "description": "",
                        "groups": [
                            {
                                "group_id": "sg-99882ad1",
                                "group_name": "sshd"
                            },
                            {
                                "group_id": "sg-fc64c6b4",
                                "group_name": "http+https"
                            }
                        ],
                        "ipv6_addresses": [],
                        "mac_address": "0e:2a:97:0c:aa:9a",
                        "network_interface_id": "eni-ce1c7154",
                        "owner_id": "229792048549",
                        "private_dns_name": "ip-172-31-32-142.ec2.internal",
                        "private_ip_address": "172.31.32.142",
                        "private_ip_addresses": [
                            {
                                "primary": true,
                                "private_dns_name": "ip-172-31-32-142.ec2.internal",
                                "private_ip_address": "172.31.32.142"
                            }
                        ],
                        "source_dest_check": true,
                        "status": "in-use",
                        "subnet_id": "subnet-9a2543c0",
                        "vpc_id": "vpc-bc7408c5"
                    }
                ],
                "placement": {
                    "availability_zone": "us-east-1c",
                    "group_name": "",
                    "tenancy": "default"
                },
                "private_dns_name": "ip-172-31-32-142.ec2.internal",
                "private_ip_address": "172.31.32.142",
                "product_codes": [],
                "public_dns_name": "",
                "root_device_name": "/dev/sda1",
                "root_device_type": "ebs",
                "security_groups": [
                    {
                        "group_id": "sg-99882ad1",
                        "group_name": "sshd"
                    },
                    {
                        "group_id": "sg-fc64c6b4",
                        "group_name": "http+https"
                    }
                ],
                "source_dest_check": true,
                "state": {
                    "code": 80,
                    "name": "stopped"
                },
                "state_reason": {
                    "code": "Client.UserInitiatedShutdown",
                    "message": "Client.UserInitiatedShutdown: User initiated shutdown"
                },
                "state_transition_reason": "User initiated (2018-07-01 01:49:14 GMT)",
                "subnet_id": "subnet-9a2543c0",
                "tags": {
                    "Name": "solomon-test",
                    "NightlyBackup": "Yes"
                },
                "virtualization_type": "hvm",
                "vpc_id": "vpc-bc7408c5"
            },
            {
                "ami_launch_index": 0,
                "architecture": "x86_64",
                "block_device_mappings": [
                    {
                        "device_name": "/dev/xvda",
                        "ebs": {
                            "attach_time": "2018-07-04T19:54:52+00:00",
                            "delete_on_termination": true,
                            "status": "attached",
                            "volume_id": "vol-0d6dbd54eeffd74e9"
                        }
                    }
                ],
                "client_token": "",
                "ebs_optimized": false,
                "ena_support": true,
                "hypervisor": "xen",
                "iam_instance_profile": {
                    "arn": "arn:aws:iam::229792048549:instance-profile/ec2-s3-full-access",
                    "id": "AIPAID3GG2QMCRY7TOW56"
                },
                "image_id": "ami-b70554c8",
                "instance_id": "i-05736d2c52da72184",
                "instance_type": "t2.micro",
                "key_name": "general_key",
                "launch_time": "2018-07-04T19:54:51+00:00",
                "monitoring": {
                    "state": "disabled"
                },
                "network_interfaces": [
                    {
                        "attachment": {
                            "attach_time": "2018-07-04T19:54:51+00:00",
                            "attachment_id": "eni-attach-444ae1fe",
                            "delete_on_termination": true,
                            "device_index": 0,
                            "status": "attached"
                        },
                        "description": "",
                        "groups": [
                            {
                                "group_id": "sg-99882ad1",
                                "group_name": "sshd"
                            },
                            {
                                "group_id": "sg-fc64c6b4",
                                "group_name": "http+https"
                            }
                        ],
                        "ipv6_addresses": [],
                        "mac_address": "12:90:09:b0:58:c6",
                        "network_interface_id": "eni-487c11eb",
                        "owner_id": "229792048549",
                        "private_dns_name": "ip-172-31-91-170.ec2.internal",
                        "private_ip_address": "172.31.91.170",
                        "private_ip_addresses": [
                            {
                                "primary": true,
                                "private_dns_name": "ip-172-31-91-170.ec2.internal",
                                "private_ip_address": "172.31.91.170"
                            }
                        ],
                        "source_dest_check": true,
                        "status": "in-use",
                        "subnet_id": "subnet-66f7984a",
                        "vpc_id": "vpc-bc7408c5"
                    }
                ],
                "placement": {
                    "availability_zone": "us-east-1a",
                    "group_name": "",
                    "tenancy": "default"
                },
                "private_dns_name": "ip-172-31-91-170.ec2.internal",
                "private_ip_address": "172.31.91.170",
                "product_codes": [],
                "public_dns_name": "",
                "root_device_name": "/dev/xvda",
                "root_device_type": "ebs",
                "security_groups": [
                    {
                        "group_id": "sg-99882ad1",
                        "group_name": "sshd"
                    },
                    {
                        "group_id": "sg-fc64c6b4",
                        "group_name": "http+https"
                    }
                ],
                "source_dest_check": true,
                "state": {
                    "code": 80,
                    "name": "stopped"
                },
                "state_reason": {
                    "code": "Client.UserInitiatedShutdown",
                    "message": "Client.UserInitiatedShutdown: User initiated shutdown"
                },
                "state_transition_reason": "User initiated (2018-07-05 04:27:10 GMT)",
                "subnet_id": "subnet-66f7984a",
                "tags": {
                    "NightlyBackup": "Yes"
                },
                "virtualization_type": "hvm",
                "vpc_id": "vpc-bc7408c5"
            }
        ]
    }
}

TASK [gather-ec2-facts : Set fact instances] **********************************************************************************************************************************************************************
ok: [localhost] => {"ansible_facts": {"instances": ["i-0468fc479c884d8b7", "i-04ff7bb389bdf86f0", "i-05736d2c52da72184"]}, "changed": false}

TASK [gather-ec2-facts : Map Name] ********************************************************************************************************************************************************************************
ok: [localhost] => {"ansible_facts": {"map_name": "[u'solomon-test-2', u'solomon-test', Undefined]"}, "changed": false}

TASK [gather-ec2-facts : debug] ***********************************************************************************************************************************************************************************
ok: [localhost] => {
    "map_name": "[u'solomon-test-2', u'solomon-test', Undefined]"
}

TASK [gather-ec2-facts : debug] ***********************************************************************************************************************************************************************************
ok: [localhost] => {
    "instances": [
        "i-0468fc479c884d8b7",
        "i-04ff7bb389bdf86f0",
        "i-05736d2c52da72184"
    ]
}

Thanks for bringing up an interesting puzzle.

My solution (without analyzing why you are doing and what) is:

  - name: Map Name
    set_fact:
      map_name: "{{ ec2_facts.instances |  map(attribute='tags.Name') | select('defined')|list  }}"

It uses select filter which passes only those element of the list which are match for an argument. I pass 'defined' filter to reject all undefined elements.

I hope this will help. Anyway, nice puzzle, thanks.

Hey thanks for the help! It's a good step forward but I really wanted to replace undefined with some sort of placeholder. Then I can iterate through the list and replace the placeholder with the corresponding i-#.

The end result I want is a list that says: [solomon-test-2, solomon-test, i-05736d2c52da72184]

Oh, that's simple too. There are filters map and default.

      map_name: "{{ ec2_facts.instances |  map(attribute='tags.Name') | map('default', 'foobar')|list  }}"

That's what I needed! I can manipulate the list like I wanted now! I looked up defaults in ansible and did not see this command. Thanks a lot.