How to get ec2 instance id tag when it's in an autoscaling group - a Jinja2 escaping problem?

[Stephen Tan]

Sounds simple, but it isn't.

I want to create a variable called "instance_role" which is set to the aws:autoscaling:groupName on the instance. 

However, there is a formatting problem as the colons are used by Jinja and I can't figure out how to escape them. 

The role: 

---

- name: Get our facts

  action: ec2_facts

- name: Using the instance ID, we can get our tags

  ec2_tag:

    resource: "{{ ansible_ec2_instance_id }}"

    state: list

    region: "{{ ansible_ec2_placement_region }}"

  register: instance_tags

- debug: var=instance_tags

# example output for reference

#ok: [localhost] => {

#    "instance_tags": {

#        "changed": false,

#        "invocation": {

#            "module_args": "",

#            "module_name": "ec2_tag"

#        },

#        "tags": {

#            "Name": "trainsmart-openvpnas-prod",

#            "aws:autoscaling:groupName": "openvpnas",

#            "environment": "access",

#            "region": "eu-west-1",

#            "stage": "prod"

#        }

#    }

#}

- name: Extract our instance role tag - ie aws:autoscaling:groupName value

  set_fact:

    instance_role: "{{ instance_tags.tags.aws:autoscaling:groupName }}"

- debug: var=instance_role

Outputs the following result:

root@ip-172-16-0-227:~/ansible# ansible-playbook local.yml  -t get_role_tags

PLAY [Base config and return register for instance roles for final config] ****

GATHERING FACTS ***************************************************************

ok: [localhost]

TASK: [get_role_tags | Get our facts] *****************************************

ok: [localhost]

TASK: [get_role_tags | Using the instance ID, we can get our tags] ************

ok: [localhost]

TASK: [get_role_tags | debug var=instance_tags] *******************************

ok: [localhost] => {

    "instance_tags": {

        "changed": false,

        "invocation": {

            "module_args": "",

            "module_name": "ec2_tag"

        },

        "tags": {

            "Name": "trainsmart-openvpnas-prod",

            "aws:autoscaling:groupName": "openvpnas",

            "environment": "access",

            "org": "trainsmart",

            "region": "eu-west-1",

            "stage": "prod"

        }

    }

}

TASK: [get_role_tags | Extract our instance role tag - ie aws:autoscaling:groupName value] ***

fatal: [localhost] => template error while templating string: expected token 'end of print statement', got ':'

[Stephen Tan]

OK - someone called halberom on freenode #ansible gave me the answer:

    # A better way of referencing dict elements to avoid escaping issues

    instance_role: "{{ instance_tags['tags']['aws:autoscaling:groupName'] }}"

this is a cleaner way of getting to the dictionary.