get hostname from multihost

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1

Hello,

I try to automate MongoDB installation with Ansible, but i can’t create a replica set members automatically.

I want to get automatically 3 host’s hostnames and add to members. I tried to use setup module and with ansible_hostname and registered to variables but I failed.

Thanks in advance

  • name: get hostname
    setup:
    filter: ansible_hostname

  • name: debug
    debug:
    var: ansible_hostname
    register: mongodb1, mongodb2, mongodb3

  • name: replica set
    mongodb_replicaset:
    login_host: localhost
    login_user: admin
    login_password: test
    replica_set: rs0
    members:

  • {{ mongodb1 }}:27017

  • {{ mongodb2 }}:27017

  • {{ mongodb3 }}:27017
    when: groups.mongod.index(inventory_hostname) == 0

2

Hello,

I try to automate MongoDB installation with Ansible, but i can't create a replica set members automatically.

I want to get automatically 3 host's hostnames and add to members. I tried to use setup module and with ansible_hostname
and registered to variables but I failed.

Thanks in advance

Hello Azir,

it is unclear to me where these hostnames are coming from. And as far as I know you can only register one variable with
register:

Regards
         Racke

3

Hello Stefan,

I pasted here only part of my playbook. I have 3 remote servers and i want to get their hostnames and assign them to mongo replica set member section.

For example;

Server 1 hostname; test1

Server 2 hostname; test2

Server 3 hostname; test3

I want to register each hostname to one variable.

Test1 should assign to “mongodb1” variable

Test2 should assign to mongodb2 variable

Test3 should assign to mongosb3 variable

I hope i was able to explain what i want try to do.

Regards
Azir

Stefan Hornburg (Racke) <racke@linuxia.de> şunları yazdı (4 Şub 2020 23:58):

4

Let's assume we have the inventory

  $ cat hosts
  [rs0]
  test_01
  test_02
  test_03

The playbook below should do the job

  - hosts: rs0
    tasks:
      - set_fact:
          mongodb_members: "{{ [0,1,2]|map('extract', groups.rs0)|list }}"
        run_once: true
      - name: replica set
        mongodb_replicaset:
          login_host: localhost
          login_user: admin
          login_password: test
          replica_set: rs0
          members: "{{ mongodb_members }}"
        when: groups.rs0.index(inventory_hostname) == 0

Notes

1) See "Selecting values from arrays or hashtables"
   https://docs.ansible.com/ansible/devel/user_guide/playbooks_filters.html#selecting-values-from-arrays-or-hashtables
   First 3 members of the group rs0 are replicaset members.

2) See "mongodb_replicaset – Initialises a MongoDB replicaset"
   https://docs.ansible.com/ansible/latest/modules/mongodb_replicaset_module.html
   members:
   - A comma-separated string or a yaml list consisting of the replicaset
     members.
   - If a port number is not provided then 27017 is assumed.

3) The Ansible task "replica set" will run on the first member of the group
   rs0.

HTH,

  -vlado

5

Thanks Vladimir, I’ll check them out.

Vladimir Botka <vbotka@gmail.com>, 5 Şub 2020 Çar, 11:02 tarihinde şunu yazdı: