CODEWITHSUNDEEP
ansible
TieDad
TieDad

Reputation: 9889

How to deal with two lists in Ansible?

I'm going to use Ansible script to create Kafka topics. I define a YAML Hash var for topics to create as:

topics:
  topic1:
    partitions: 1
    replication_factor: 2
  topic2:
    partitions: 1
    replication_factor: 2

Before create them, I need first check if a topic has existed. I can use kafka-topics.sh --list --zookeeper localhost:2181 to get the list of existing topic names, then compare with topics hash to get a list of topics to create, then call kafka-topics.sh --create --topic name to create topics.

How to implement this?

Upvotes: 0

Views: 619

Answers (2)

TieDad
TieDad

Reputation: 9889

Thanks for linuxdynasty's answer. But I don't want to write a module just for this simple task. Finally I worked out the following solution. I'm posting here for people referencing.

---
- name: Get existing topic list
  become_user: root
  become: yes
  become_method: sudo
  shell: /opt/kafka/bin/kafka-topics.sh --list --zookeeper localhost:2181
  register: existings

- name: Print existing topic list
  debug: msg="{{existings.stdout | regex_replace("\\n", " ")}}"

- name: Create topics
  become_user: root
  become: yes
  become_method: sudo
  shell: >
    if [[ `echo "{{existings.stdout}}" | grep {{item.key}}` != {{item.key}} ]]; then
    /opt/kafka/bin/kafka-topics.sh --create --zookeeper localhost:2181
    --topic {{item.key}} --partitions {{item.value.partitions}}
    --replication-factor {{item.value.replication_factor}};
    fi
  with_dict: "{{kafka_topics}}"

Upvotes: 1

linuxdynasty
linuxdynasty

Reputation: 376

It seems like you will need to create a kafka facts module. The module would be called something like this kafaka_topics_facts. The module will return the topics and than from there you can create the topics that do not exist. Please read this Developing Ansible Modules

Upvotes: 0

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