creating dictionary with ansible - loops

Question

I want to create a dictionary in ansible from a list; using some variables for the value in the key-value pair of the dictionary, but it seems to be not working.
I've simplified just to the problem and created a sample playbook to reproduce the issue, can someone help me out. Thanks!
here is my playbook
---
- name: create dictionary test
hosts: all
connection: local
gather_facts: False
vars:
ports: [80, 443]
server_base: "org.com"
tasks:
- name: print the ports
debug:
msg: "ports: {{ports}}"
- name: create a dictionary
set_fact:
#server_rules: "{{server_rules|default([]) + [{'server': '{{server_base}}-{{item}}', 'port': item}]}}"
server_rules: "{{server_rules|default([]) + [{'server': '{{server_base}}', 'port': item}]}}"
loop: "{{ports|flatten(1)}}"
- name: output
debug:
msg: "server_rules: {{server_rules}}"
With the above it works, the output as below:
$ansible-playbook -i "localhost," dicttest.yaml
PLAY [create dictionary test] ***************************************************************************************************************************************
TASK [print the ports] **********************************************************************************************************************************************
ok: [localhost] => {
"msg": "ports: [80, 443]"
}
TASK [create a dictionary] ******************************************************************************************************************************************
ok: [localhost] => (item=80)
ok: [localhost] => (item=443)
TASK [output] *******************************************************************************************************************************************************
ok: [localhost] => {
"msg": "server_rules: [{'server': 'org.com', 'port': 80}, {'server': 'org.com', 'port': 443}]"
}
PLAY RECAP **********************************************************************************************************************************************************
localhost : ok=3 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
But when I change set fact to (uncomment the one commented line and comment the other one)
server_rules: "{{server_rules|default([]) + [{'server': '{{server_base}}-{{item}}', 'port': item}]}}"
it fails with the following error
$ansible-playbook -i "localhost," dicttest.yaml
PLAY [create dictionary test] ***************************************************************************************************************************************
TASK [print the ports] **********************************************************************************************************************************************
ok: [localhost] => {
"msg": "ports: [80, 443]"
}
TASK [create a dictionary] ******************************************************************************************************************************************
ok: [localhost] => (item=80)
ok: [localhost] => (item=443)
TASK [output] *******************************************************************************************************************************************************
fatal: [localhost]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'item' is undefined\n\nThe error appears to be in '/Users/dev/dicttest.yaml': line 22, column 7, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n - name: output\n ^ here\n"}
PLAY RECAP **********************************************************************************************************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0
Can someone explain how to get this working.

Answer 1

Q: Given the data
ports: [80, 443]
server_base: org.com
create a list of dictionaries
server_rules:
- port: 80
server: org.com-80
- port: 443
server: org.com-443
A: The task below gives the expected result
- name: create a list of dictionaries
set_fact:
server_rules: "{{ server_rules|default([]) +
[{'server': server_base + '-' + item|string,
'port': item}] }}"
loop: "{{ ports }}"
It's not necessary to iterate the list in a task. The declaration of the variables below does the same job
servers: "{{ [server_base]|
product(ports)|
map('join', '-')|
map('community.general.dict_kv', 'server')|
list }}"
server_rules: "{{ servers|
zip(ports|map('community.general.dict_kv', 'port'))|
map('combine')|
list }}"
Notes:
Double braces "{{ }}" can't be nested. The expression below is wrong
"{{ var1 + ['{{server_base}}-'] }}"
Correct
"{{ var1 + [server_base + '-'] }}"
In YAML, the operator plus "+" is used both to concatenate strings and lists. This is because a string in YAML is technically a list of characters. It's recommended to use "~" to concatenate strings
Also correct
"{{ var1 + [server_base ~ '-'] }}"
Use var attribute in debug. The output is more readable with stdout_callback = yaml
- debug:
var: server_rules
The created variable server_rules is a list. The items are dictionaries. Hence, it's a list of dictionaries.
The variable ports is a simple list. There is no need to use the filter flatten.
The combination of "hosts: all" and "connection: local" would make to run all hosts at the localhost
hosts: all
connection: local
Use "hosts: localhost" if you want to run the playbook at the localhost. In this case "connection: local" is the default
hosts: localhost
If you want to run a task at the localhost, but still want the play to read the variables for all hosts, use "delegate_to: localhost" and limit the task to "run_once: true". For example
- hosts: all
tasks:
- copy:
content: "{{ ansible_play_hosts|to_nice_yaml }}"
dest: /tmp/ansible_play_hosts.yml
delegate_to: localhost
run_once: true

Answer 2

got an answer from another person outside of stackoverflow, posting here just to make sure anyone looking at this, gets the solution as well
changing as follows fixes the problem
server_rules: "{{server_rules|default([]) + [{'server': '{{server_base}}-' + item|string, 'port': item}]}}"
The complete working playbook
---
- name: create dictionary test
hosts: all
connection: local
gather_facts: False
vars:
ports: [80, 443]
server_base: "org.com"
tasks:
- name: print the ports
debug:
msg: "ports: {{ports}}"
- name: create a dictionary
set_fact:
server_rules: "{{server_rules|default([]) + [{'server': '{{server_base}}-' + item|string, 'port': item}]}}"
loop: "{{ports|flatten(1)}}"
- name: output
debug:
msg: "server_rules: {{server_rules}}"