ansible: how to become a passwordless user - ansible

Question

I'm trying to achieve the following with ansible
create a user without a password
adduser test <-- ok and works on linux machine and works with ansible
change to user test
su test <-- works on linux machine, but fails with ansible. I get
incorrect password message
copy a file from location1 to location2 as a test user and change a file content.
cp loc1/testfile.txt loc2/testfile.txt && echo "hello" > testfile.txt
---
- name: This is a hello-world example
hosts: all
tasks:
- name: create a passwordless test user
action: user name=test state=present
become: yes
become_user: root
- name: Create a file called '/tmp/testfile.txt' with the content 'hello' using test user.
copy:
content: hello
dest: /tmp/testfile.txt
owner: test
group: test
become_user: test
primary conditions:
at a moment of execution the file testfile.txt is already created on linux machine and has a group root and user root. I want to override the file and assign different user and group.
I've tried various combination, including
copy:
content: hello
dest: /tmp/testfile.txt
owner: test
group: test
become: yes
become_user: test
copy:
content: hello
dest: /tmp/testfile.txt
owner: test
group: test
become: yes
become_user: test
become_method: su
copy:
content: hello
dest: /tmp/testfile.txt
owner: test
group: test
become: yes
copy:
content: hello
dest: /tmp/testfile.txt
owner: test
group: test
become_user: test
become_method: su
always getting a message about the password being incorrect. The awkward moment is that test user has no password
What am I doing wrong?
Updates:
Tried this
How to achieve sudo su - <user> and run all command in ansible <-- does not work
Found an answer - it is not possible
https://devops.stackexchange.com/questions/3588/how-do-you-simulate-sudo-su-user-in-ansible
What is the point?
to cite from Quora (source: https://www.quora.com/What-is-advantage-of-creating-passwordless-user-in-Linux)
I presume you mean processes such as a webserver, running as the
"apache" user with a locked password (shadow entry of '!!').
This is for security, in case a vulnerability is discovered in the
server code. Prior to the year 2000 or so, it was common for servers
to run as the root user, particularly as this privilege is required to
open network sockets on privileged ports (below 1024), such as 53
(DNS) or 80 (HTTP). As I recall, high-profile breaches of the bind and
sendmail servers caused developers to re-think this strategy. Since
then, services are started with root privilege, the socket opened, and
then privilege is dropped to a non-privileged user ID such as "apache"
or "named". This needs no password, since it is never intended that
anyone login. Rather, a process running as root executes a setuid()
system call to change effective user ID to this user. In the event of
a security breach, an attacker will be limited to the access lists of
this user; for instance, a vulnerable CGI script on a webserver would
be able to access the /tmp directory as the "apache" user, but be
unable to read /etc/shadow for instance, or to write an extra user
into /etc/passwd or modify system binaries in /sbin.

Answer 1

To avoid what is described in "password not being accepted for sudo user with ansible":
fatal: [testserver]: FAILED! => {"failed": true, "msg": "Incorrect su password"}
You might try using sudo, assuming you have given test user sudo rights:
# Debian systems (Ubuntu / Linux Mint / ElementryOS), add users to the sudo group
sudo usermod -aG sudo username
# On RHEL based systems (Fedora / CentOS), add users to the wheel group
sudo usermod -aG wheel username
Then:
become_user: test
become_method: sudo
Laucnhed with:
ansible-playbook -i inventory simple_playbook.yml --ask-become-pass
And enter the root password