Creating a comma separated string from a dictionary in Ansible - ansible

Question

I want to write an Ansible role to be able to alter a given Kafka topic. I am using a dictionary of key/value pairs.
The command module is then used to execute a Kafka script that take a string of comma separated values. For instance, use app_kafka_topic list:
---
app_kafka_topic:
cleanup.policy :
- "delete"
retention.ms :
- "146800000"
partitions :
- "6"
replication-factor :
- "2"
and create the string:
"cleanup.policy=delete,retention.ms=146800000,partitions=6,replication-factor=2"
This is what I have so far.
- name: Reading the Default Topic Properties
set_fact:
app_kafka_topic_properties_dicts: |
{% set res = [] -%}
{% for key in app_kafka_topic.keys() -%}
{% for value in app_kafka_topic[key] -%}
{% set ignored = res.extend([{'topic_property': key, 'value':value}]) -%}
{%- endfor %}
{%- endfor %}
{{ res }}
- name: Create Topic with Default Properties
command: "{{ kafka_bin_dir }}/{{ kafka_config_script }}
--zookeeper {{ prefix }}-kafka-{{ Kafka_node }}.{{ DNSDomain}}:{{ zookeeper_port }}
--entity-type topics
--alter
--entity-name {{ kafka_topic }}
--add-config
{{ properties }}"
with_items: "{{ app_kafka_topic_properties_dicts }}"
register: createdTopic
vars:
properties: |-
{% for key in app_kafka_topic.keys() %}
{% for value in app_kafka_topic[key] %}
"{{ key }}={{ value }}"
{%- endfor %}
{%- endfor %}
However, the properties variable is not concatenating the values to the end of a string. Is there a way to append the values to a string and separate them by a comma?

Answer 1

Is this the code that you're looking for?
play.yml
- hosts: localhost
gather_facts: no
vars:
string: ""
app_kafka_topic:
cleanup.policy :
- "delete"
retention_ms :
- "146800000"
partitions :
- "6"
replication_factor :
- "2"
tasks:
- set_fact:
string: "{{ string }}{{ (index > 0)|ternary(',','') }}{{ item.key }}={{ item.value[0] }}"
loop: "{{ app_kafka_topic|dict2items }}"
loop_control:
index_var: index
- debug:
var: string
$ ansible-playbook play.yml | grep string
"string": "retention_ms=146800000,cleanup.policy=delete,replication_factor=2,partitions=6"