Ansible getent module's loop output results parsing - ansible

Question

I am trying to check if a number of users are present or not in the managed node using getent module and create a list of users who are not present.
The piece of code is:
- getent:
database: passwd
key: "{{ item }}"
fail_key: no
register: x
loop:
- "user1"
- "user2"
- debug: var=x.results
- set_fact:
fail_list: "{{ x.results | }}"
I am stuck at this point.
Is there any way I can save the users who are not present to the variable fail_list as a list?
In the above example, user1 is not present and user2 is present in the managed node.
The ansible version I am using is 2.9 and the debug output is a list of dicts as below:
"x.results": [
{
"ansible_facts": {
"getent_passwd": {
"user1": null
}
},
"ansible_loop_var": "item",
"changed": false,
"failed": false,
"invocation": {
"module_args": {
"database": "passwd",
"fail_key": false,
"key": "user1",
"service": null,
"split": null
}
},
"item": "user1",
"msg": "One or more supplied key could not be found in the database."
},
{
"ansible_facts": {
"discovered_interpreter_python": "/usr/bin/python",
"getent_passwd": {
"user2": [
"x",
"0",
"0",
"user2",
"/home/user2",
"/bin/bash"
]
}
},
"ansible_loop_var": "item",
"changed": false,
"failed": false,
"invocation": {
"module_args": {
"database": "passwd",
"fail_key": false,
"key": "user2",
"service": null,
"split": null
}
},
"item": "user2"
},

Answer 1

Run getent once and search the list of users. For example
- hosts: localhost
tasks:
- getent:
database: passwd
- debug:
msg: User {{ item }} exists.
loop:
- root
- user1
- user2
when: item in my_users
vars:
my_users: "{{ getent_passwd.keys()|list }}"
gives
ok: [localhost] => (item=root) => {
"msg": "User root exists."
}
skipping: [localhost] => (item=user1)
skipping: [localhost] => (item=user2)