Variable is empty or no defined in Ansible - ansible

Question

When I run my playbook I see the following error:
fatal: [localhost]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: list object has no element 0\n\nThe e
rror appears to be in '/etc/ansible/loyalty/tasks/create_ec2_stage.yaml': line 63, column 7, but may\nbe elsewhere in the file depending on the exac
t syntax problem.\n\nThe offending line appears to be:\n\n register: ec2_metadata\n - name: Parse < JSON >\n ^ here\n"}
I run the playbook this way:
/usr/bin/ansible-playbook -i hosts --extra-vars "CARRIER=xx" tasks/create_ec2_stage.yaml
Here is my playbook:
---
- name: New EC2 instances
hosts: localhost
gather_facts: no
vars_files:
- /etc/ansible/loyalty/vars/vars.yaml
tasks:
- name: Run EC2 Instances
amazon.aws.ec2_instance:
name: "new-{{ CARRIER }}.test"
aws_secret_key: "{{ ec2_secret_key }}"
aws_access_key: "{{ ec2_access_key }}"
region: us-east-1
key_name: Kiu
instance_type: t2.medium
image_id: xxxxxxxxxxxxx
wait: yes
wait_timeout: 500
volumes:
- device_name: /dev/xvda
ebs:
volume_type: gp3
volume_size: 20
delete_on_termination: yes
vpc_subnet_id: xxxxxxxxxxxx
network:
assign_public_ip: no
security_groups: ["xxxxxxxxxx", "xxxxxxxxxxx", "xxxxxxxxxxxxxx"]
tags:
Enviroment: TEST
count: 1
- name: Pause Few Seconds
pause:
seconds: 20
prompt: "Please wait"
- name: Get Information for EC2 Instances
ec2_instance_info:
region: us-east-1
filters:
"tag:Name": new-{{ CARRIER }}.test
register: ec2_metadata
- name: Parse JSON
set_fact:
ip_addr: "{{ ec2_metadata.instances[0].network_interfaces[0].private_ip_address }}"
If I create a slightly smaller playbook to query the private IP address of an existing instance, I don’t see any error.
---
- name: New EC2 Instances
hosts: localhost
gather_facts: no
vars_files:
- /etc/ansible/loyalty/vars/vars.yaml
vars:
pwd_alias: "{{ lookup('password', '/dev/null length=15 chars=ascii_letters') }}"
CARRIER_UPPERCASE: "{{ CARRIER | upper }}"
tasks:
- set_fact:
MY_PASS: "{{ pwd_alias }}"
- name: Get EC2 info
ec2_instance_info:
region: us-east-1
filters:
"tag:Name": new-{{ CARRIER }}.stage
register: ec2_metadata
- name: Parsing JSON
set_fact:
ip_addr: "{{ ec2_metadata.instances[0].network_interfaces[0].private_ip_address }}"
- name: Show Result
debug:
msg: "{{ ip_addr }}"
Results in
TASK [Show Result] ******************************************************
ok: [localhost] => {
"msg": "172.31.x.x"
}
I am creating an EC2 instance on Amazon and querying the private IP to use that IP on other services like router53 and Cloudflare, other tasks do not add them because the error is in the fact.

Answer 1

You don't have to query AWS with the ec2_instance_info module since the module amazon.aws.ec2_instance already returns you the newly created EC2 when the parameter wait is set to yes, as it is in your case.
You just need to register the return of this task.
So, given the two tasks:
- name: Run EC2 Instances
amazon.aws.ec2_instance:
name: "new-{{ CARRIER }}.test"
aws_secret_key: "{{ ec2_secret_key }}"
aws_access_key: "{{ ec2_access_key }}"
region: us-east-1
key_name: Kiu
instance_type: t2.medium
image_id: xxxxxxxxxxxxx
wait: yes
wait_timeout: 500
volumes:
- device_name: /dev/xvda
ebs:
volume_type: gp3
volume_size: 20
delete_on_termination: yes
vpc_subnet_id: xxxxxxxxxxxx
network:
assign_public_ip: no
security_groups: ["xxxxxxxxxx", "xxxxxxxxxxx", "xxxxxxxxxxxxxx"]
tags:
Enviroment: TEST
count: 1
register: ec2
- set_fact:
ip_addr: "{{ ec2.instance[0].private_ip_address }}"
You should have the private IP address of the newly created EC2 instance.