How to pass multiple lines as value to Ansible - ansible

Question

I'm trying to pass multiple lines as a value to my Ansible file But it's only just passing the first line.
cat slot_number.txt
slot4
slot2
slot1
slot3
My ansible file as below
update_bios.yml
tasks:
- name: Powering off slot number
command: "/usr/local/bin/power-util {{slot_number}} off"
- name: Starting to update BIOS
command: "/usr/bin/fw-util {{slot_number}} --update --bios"
ansible-playbook -l myhosts update_bios.yml -e "slot_number=$(cat slot_number.txt)"
I want to run my command like below:
/usr/local/bin/power-util slot1 off
/usr/local/bin/power-util slot2 off
/usr/local/bin/power-util slot3 off

Answer 1

Edit after understanding the question details:
Map the slot numbers to a host:
cat slot_numbers.yml
slot_numbers:
server1:
-slot4
-slot2
server2:
-slot1
-slot3
After that distinguish between hosts in the playbook as follows,
tasks:
- name: Powering off slot number
command: "/usr/local/bin/power-util {{ item }} off"
loop: "{{ slot_numbers[inventory_hostname] }}"
- name: Starting to update BIOS
command: "/usr/bin/fw-util {{ item }} --update --bios"
loop: "{{ slot_numbers[inventory_hostname] }}"
In this approach we are doing the mapping between hosts and slots in the slot_numbers variable file. Alternatively, you can define the variables as host variables also.
Previous answer:
Ansible understands yaml and json.
Also, playbook needs to handle what happens with the data available to it via variables. So, if you want to loop through a list of slot numbers you have to tell your playbook to do exactly that.
Define your slot number file as follows:
In this file, you are creating a list of slot numbers and assigning it to the key 'slot_numbers'
cat slot_numbers.yml
slot_numbers:
-slot4
-slot2
-slot1
-slot3
Modify your update_bios.yml to loop through the slot numbers you are passing,
tasks:
- name: Powering off slot number
command: "/usr/local/bin/power-util {{ item }} off"
loop: "{{ slot_numbers }}"
- name: Starting to update BIOS
command: "/usr/bin/fw-util {{ item }} --update --bios"
loop: "{{ slot_numbers }}"
then use:
ansible-playbook -l myhosts update_bios.yml -e "#slot_numbers.yml"
Detailed documentation of how to use variables and playbooks can be found here

Answer 2

Something like this should work.
vars:
slot_numbers: "{{ lookup('file', './slot_number.txt').splitlines() }}"
tasks:
- name: Powering off slot number
command: "/usr/local/bin/power-util {{ item }} off"
loop: "{{ slot_numbers }}"
- name: Starting to update BIOS
command: "/usr/bin/fw-util {{ item }} --update --bios"
loop: "{{ slot_numbers }}"