Loop isn't iterating over last line of list - loops

Question

I have created a template within a playbook which I want to iterate through with a list of hashes. The output of this I want to add to another var to use in a following module.
The template works and the loop looks like it works, but it never adds the last item in the list. I have recreated it in a test play.
---
- hosts: localhost
tasks:
- name: Init
set_fact:
foo: []
fqdn: "test.com"
template: []
- name: portlist
set_fact:
portlist:
- { port: 9091, index: 1 }
- { port: 9092, index: 2 }
- { port: 9093, index: 3 }
- { port: 9094, index: 4 }
- name: generate policy
set_fact:
template:
- name: "traffic to {{ item.port }}"
index: "{{ item.index }}"
match:
desc: "[{{ item.port }}]" # The field needs to be passed as a list
name: "{{ fqdn }}_{{ item.port }}"
port: "{{ item.port }}"
foo: "{{ foo + template }}"
loop: "{{ portlist }}"
- debug:
var: foo
I understand I can make this play smaller with defaults rather than initializing vars but this felt easier to read for troubleshooting.
The play results in a list of hashes which then I can input into a policy module. However it only ever gives me 3 items in the list and misses off the last item in the portlist.
TASK [debug] ***************************************************
ok: [localhost] => {
"foo": [
{
"action": {
"ref": "test.com_9091",
"this": true
},
"enable": true,
"index": "1",
"match": {
"port": {
"criteria": "IS_IN",
"port": [
9091
]
}
},
"name": "traffic to 9091"
},
{
"action": {
"ref": "test.com_9092",
"this": true
},
"enable": true,
"index": "2",
"match": {
"port": {
"criteria": "IS_IN",
"port": [
9092
]
}
},
"name": "traffic to 9092"
},
{
"action": {
"ref": "test.com_9093",
"this": true
},
"enable": true,
"index": "3",
"match": {
"port": {
"criteria": "IS_IN",
"port": [
9093
]
}
},
"name": "traffic to 9093"
}
]
}

Answer 1

Your problem is caused by the fact that variables defined via set_fact aren't available until after the set_fact task has finished. This means that when you set:
foo: "{{ foo + template }}"
You see the value of template from the previous loop iteration.
One way of dealing with this is to rewrite your set_fact task to set foo directly:
---
- hosts: localhost
gather_facts: false
vars:
fqdn: "test.com"
portlist:
- {port: 9091, index: 1}
- {port: 9092, index: 2}
- {port: 9093, index: 3}
- {port: 9094, index: 4}
tasks:
- name: generate policy
set_fact:
foo: >-
{{
foo + [{
'name': 'traffic to {}'.format(item.port),
'index': item.index,
'match': {
'desc': "[{}]".format(item.port),
'name': '{}_{}'.format(fqdn, item.port),
'port': item.port
}
}]
}}
vars:
foo: []
loop: "{{ portlist }}"
- debug:
var: foo
This will output:
TASK [debug] *********************************************************************************************************************************************************************************
ok: [localhost] => {
"foo": [
{
"index": 1,
"match": {
"desc": "[9091]",
"name": "test.com_9091",
"port": 9091
},
"name": "traffic to 9091"
},
{
"index": 2,
"match": {
"desc": "[9092]",
"name": "test.com_9092",
"port": 9092
},
"name": "traffic to 9092"
},
{
"index": 3,
"match": {
"desc": "[9093]",
"name": "test.com_9093",
"port": 9093
},
"name": "traffic to 9093"
},
{
"index": 4,
"match": {
"desc": "[9094]",
"name": "test.com_9094",
"port": 9094
},
"name": "traffic to 9094"
}
]
}
If you find your template-based solution more readable, you could rewrite it using two set_fact tasks like this:
---
- hosts: localhost
gather_facts: false
vars:
fqdn: "test.com"
portlist:
- {port: 9091, index: 1}
- {port: 9092, index: 2}
- {port: 9093, index: 3}
- {port: 9094, index: 4}
tasks:
- name: generate policy
set_fact:
template:
name: "traffic to {{ item.port }}"
index: "{{ item.index }}"
match:
desc: "[{{ item.port }}]" # The field needs to be passed as a list
name: "{{ fqdn }}_{{ item.port }}"
port: "{{ item.port }}"
loop: "{{ portlist }}"
register: foo
- set_fact:
foo: "{{ foo.results | map(attribute='ansible_facts.template') | list }}"
- debug:
var: foo