How can I print all extra-vars before playbook is started - variables

Question

I have wired problem with running ansible
I'd like to print to log or anywhere else the extra-vars I'm executing the playbook with.
I am running the following command:
ansible-playbook /foo/main.yml --extra-vars "main_playbook=app_install start_path=work" --extra-vars {"db_config":{"db_multi_config":["value1","value2"]}}'
with the following main.yml playbook
- name: start playbook
import_playbook: "{{ playbook_dir }}/{{ main_playbook}}/{{ start_path}}.yml"
I'd like to print the values of all extra-vars passed on the command line before it gets to main.yml. Is there any way to do this?

Answer 1

You can get this information in the output running ansible in full debug mode:
Given the following test.yml playbook:
- hosts: localhost
gather_facts: false
and running it with the command:
ansible-playbook test.yml -vvvv -e toto=bla -e '{"test1":2}'
I get the following result (see the debug lines for playbook before play starts)
ansible-playbook [core 2.11.3]
config file = None
configured module search path = ['/home/user/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
ansible python module location = /usr/local/lib/python3.8/dist-packages/ansible
ansible collection location = /home/user/.ansible/collections:/usr/share/ansible/collections
executable location = /usr/local/bin/ansible-playbook
python version = 3.8.10 (default, Jun 2 2021, 10:49:15) [GCC 9.4.0]
jinja version = 2.11.3
libyaml = True
No config file found; using defaults
The vault password file /home/user/bin/vault-keyring-client is a client script.
Executing vault password client script: /home/user/bin/vault-keyring-client --vault-id avaultid1
The vault password file /home/user/bin/vault-keyring-client is a client script.
Executing vault password client script: /home/user/bin/vault-keyring-client --vault-id avaultid2
The vault password file /home/user/bin/vault-keyring-client is a client script.
Executing vault password client script: /home/user/bin/vault-keyring-client --vault-id avaultid3
setting up inventory plugins
host_list declined parsing /etc/ansible/hosts as it did not pass its verify_file() method
script declined parsing /etc/ansible/hosts as it did not pass its verify_file() method
auto declined parsing /etc/ansible/hosts as it did not pass its verify_file() method
Parsed /etc/ansible/hosts inventory source with ini plugin
Loading callback plugin default of type stdout, v2.0 from /usr/local/lib/python3.8/dist-packages/ansible/plugins/callback/default.py
Skipping callback 'default', as we already have a stdout callback.
Skipping callback 'minimal', as we already have a stdout callback.
Skipping callback 'oneline', as we already have a stdout callback.
PLAYBOOK: test.yml **********************************************************************************************************************
Positional arguments: test.yml
verbosity: 4
connection: smart
timeout: 10
become_method: sudo
tags: ('all',)
inventory: ('/etc/ansible/hosts',)
extra_vars: ('toto=bla', '{"test1":2}')
forks: 5
1 plays in test.yml
PLAY [all] ******************************************************************************************************************************
skipping: no hosts matched
PLAY RECAP ******************************************************************************************************************************

Answer 2

You can't separate extra vars from all other vars, because they are merged. But you can see all variables for the host. (except for setup facts, which you can browse separately with -m setup).
The trick is to print all variables from hostvars group for 'itself', ansible_host:
ansible -i inventory -e extra_vars_here -m debug -a 'msg={{hostvars[inventory_hostname]}}' all
(replace all with specific hostname if you wish).
If you are overwhelmed, you can filter it with .keys(): hostvars[inventory_hostname].keys().