Ansible loop with vars_prompt and with_sequence - ansible

Question

I have a question, can we pass a range of inputs with vars_prompt.
Can we achieve with_sequence
example:
From the below playbook, i am able to pass multiple port numbers split by ",".
prompt: Please enter the port name: 0/1,0/2,0/3,0/4,0/5
But when I want to pass the input of ports in a range.
prompt: Please enter the port name: 0/1-0/5
Do we have option how to run, will that works with nested loop
- hosts: localhost
gather_facts: no
vars_prompt:
- name: port_name
prompt: Please enter the port name
private: no
tasks:
- add_host:
name: "{{port_name}}"
groups: dynamically_created_hosts
with_items: "{{port_name.split(',')}}"
- name: Change port speed
port_speed_change:
switch_ip: "{{ip_address}}"
user: "{{user}}"
password: "{{password}}"
checkmode: "{{ansible_check_mode}}"
name: "{{items}}"
speed: "{{port_speed}}"

Answer 1

I think that's not possible directly with a library, however, you can achieve your purpose in several ways, one is using lists and loops.
Please consider two elements in your input:
I1/S1-I2/S2
I=Interface
S=Subport
In order to achieve this without errors it is necesary to run 3 loops:
Add elements in a list from your I1/S1 to I1/S_Max
Add middle elements from I_middle/0 to I_middle/S_Max
Add last elements I2/0 to I2/S2
First of all you collect your port_name variable, it is really important that you respect the sinxtax of input string:
- name: port_name
prompt: Please enter port name (format X/Y-X/Z, e.g 0/1-0/5)
private: no
Create 1st loop:
####1st cycle, first port first sub_loop
#1st sub_loop, first entry subport to maximum subport
- set_fact: port_sub_loop={{port_sub_loop|default([]) | union([item]) }}
with_sequence: start="{{ S1 }}" end="{{ S_MAX }}"
- name: Add first elements (first interface, first sub_loop)
set_fact: ports="{{ ports|default([]) | union([item.0+'/'+item.1]) }}"
with_nested:
- "{{ I1 }}"
- "{{ port_sub_loop }}"
2nd block is tricky, because it has to escape in case I1 >= I2 -2, you cannot use when condition with loops, so I decided to use a block with a rescue:
####2nd cycle, middle elements, subports are from 0 to S_MAX... There is a rescue because you cannot add a condition "with_sequence", in case I1 >= I2 -2 it will continue with rescue
#Set port interfaces loop ignoring first and last port
- name: run middle loop
block:
- set_fact: port_interfaces_middle={{port_interfaces_middle|default([]) | union([item]) }}
with_sequence: start="{{ I1|int + 1 }}" end="{{ I2|int - 1 }}"
#Set complete port sub_interfaces loop from 0 to S_MAX
- set_fact: port_sub={{port_sub|default([]) | union([item]) }}
with_sequence: start="0" end="{{ S_MAX }}"
# - name: Add middle elements (next ports starting from subport 0)
- set_fact: ports="{{ ports|default([]) | union([item.0+'/'+item.1]) }}"
with_nested:
- "{{ port_interfaces_middle }}"
- "{{ port_sub }}"
rescue:
- debug: msg='Not executed middle block'
Last part add elements for last I2:
#Set last interface sub_loop, from 0 to S2
- set_fact: port_sub_last={{port_sub_last|default([]) | union([item]) }}
with_sequence: start="0" end="{{ S2 }}"
- name: Add last elements (from last_interface)
set_fact: ports="{{ ports|default([]) | union([item.0+'/'+item.1]) }}"
with_nested:
- "{{ I2 }}"
- "{{ port_sub_last }}"
FINAL SCRIPT
vars_prompt:
- name: port_name
prompt: Please enter port name (format X/Y-X/Z, e.g 0/1-0/5)
private: no
tasks:
#Get first interface
- set_fact: I1={{ port_name | regex_search("^\d+") | int }}
#Get second interface
- set_fact: I2={{ port_name | regex_search("\-\d+") | regex_replace('^\-', '') | int }}
#Get first sub_interface
- set_fact: S1={{ port_name | regex_search("\d+\-") | regex_replace('\-$', '') | int }}
#Get second sub_interface
- set_fact: S2={{ port_name | regex_search("\d+$") | int }}
#Set highest/lowest subinterface value
- set_fact: S_MAX="{{ S1 if (S1 >= S2) else S2 }}"
- set_fact: S_MIN="{{ S1 if (S1 <= S2) else S2 }}"
####1st cycle, first port first sub_loop
#1st sub_loop, first entry subport to maximum subport
- set_fact: port_sub_loop={{port_sub_loop|default([]) | union([item]) }}
with_sequence: start="{{ S1 }}" end="{{ S_MAX }}"
- name: Add first elements (first interface, first sub_loop)
set_fact: ports="{{ ports|default([]) | union([item.0+'/'+item.1]) }}"
with_nested:
- "{{ I1 }}"
- "{{ port_sub_loop }}"
####2nd cycle, middle elements, subports are from 0 to S_MAX... There is a rescue because you cannot add a condition "with_sequence", in case I1 >= I2 -2 it will continue with rescue
#Set port interfaces loop ignoring first and last port
- name: run middle loop
block:
- set_fact: port_interfaces_middle={{port_interfaces_middle|default([]) | union([item]) }}
with_sequence: start="{{ I1|int + 1 }}" end="{{ I2|int - 1 }}"
#Set complete port sub_interfaces loop from 0 to S_MAX
- set_fact: port_sub={{port_sub|default([]) | union([item]) }}
with_sequence: start="0" end="{{ S_MAX }}"
# - name: Add middle elements (next ports starting from subport 0)
- set_fact: ports="{{ ports|default([]) | union([item.0+'/'+item.1]) }}"
with_nested:
- "{{ port_interfaces_middle }}"
- "{{ port_sub }}"
rescue:
- debug: msg='Not executed middle block'
####3rd cycle, last port until last element
#Set last interface sub_loop, from 0 to S2
- set_fact: port_sub_last={{port_sub_last|default([]) | union([item]) }}
with_sequence: start="0" end="{{ S2 }}"
- name: Add last elements (from last_interface)
set_fact: ports="{{ ports|default([]) | union([item.0+'/'+item.1]) }}"
with_nested:
- "{{ I2 }}"
- "{{ port_sub_last }}"
- debug: msg="{{ ports }}"
I don't add port_speed_change cause it must be a local library, I don't know how you are using it.
Regards