debugging module invocations in playbooks

[amenonsen]

Issue type: Feature idea
Ansible version: NA
Ansible configuration: NA
Environment: NA
Summary:

I find myself often building up complex module invocations, e.g. for the ec2 module:

# Create EC2 instances using the VPC subnets and security groups and
# access key we configured above.

- name: Set up EC2 instances
  ec2:
    exact_count: 1
    count_tag: "{{ cluster_tags }}"
    image: "{{ item.0.image }}"
    region: "{{ item.0.region }}"
    group_id: "{{ item.2.group_id }}"
    instance_type: "{{ item.0.type }}"
    vpc_subnet_id: "{{ item.1.subnets[0].id }}"
    instance_tags: "{{ cluster_tags | merge(item.0.tags) }}"
    key_name: "{{ ec2_key_name }}"
    assign_public_ip: yes
    volumes: "{{ item.0.volumes }}"
    wait: yes
  with_together:
    - instances
    - vpcs.results
    - security_groups.results
  register: ec2_instances

…and then, when something goes wrong, adding a bunch of debug: tasks above this to see what's actually getting passed in. It would be enormously and outrageously useful to be able to just add debug: to the beginning of this task and have it dump the arguments. If it's hard to deal with debug: ec2: … for some reason, I would be equally happy with debug: [no ec2:, but original args]. (Related to this is that debug ignores arguments it doesn't understand and just prints "here we are".)

Steps to reproduce: NA
Expected results: NA
Actual results: NA

[sheldonh]

I would prefer

- name: Set up EC2 instances
  debug_args: true
  ec2:
    exact_count: 1
    ...

[amenonsen]

Note: just returning dict(failed=True, msg=str(self._task.args)) from plugins/action/debug.py does most of what I wanted, and adding debug to the list of RAW_PARAM_MODULES in parsing/mod_args.py makes it possible to debug tasks like command, which take raw args.