How to output loop.index in jinja

Question

I want to be able to output the loop.index iteration to my template , i am using ansible and i have template file.j2 and inventory file have the below group

[all_servers]
app01 ansible_host=10.10.1.100
app02 ansible_host=10.10.1.102
app03 ansible_host=10.10.1.103
app04 ansible_host=10.10.1.104
app05 ansible_host=10.10.1.105
app06 ansible_host=10.10.1.106

I have jinja file inside this file value

/kafka_certification/kafka.server01.keystore.jk

So i want copy this jinja file to all nodes and i want use loop.index in part of [ server0{{ loop.index }} ] because each node have different jinja file for example kafka.server02.keystore for app02 kafka.server03.keystore for app03 kafka.server04.keystore for app04 kafka.server05.keystore for app05 kafka.server06.keystore for app06 .. loop depend on my inventory host group [all_servers]

how i can do this

ansible loop index for ansible template

no i want to user {{loop.index}} but i dont know how it this case — MuhammedOmar, May 17 '23 at 07:44
i want to change 01 only to be 02 03 04 05 05 depend on host group all_servers — MuhammedOmar, May 17 '23 at 08:06

Vladimir Botka · Accepted Answer · 2023-05-17T09:53:36.870

The play below shows how you can use the index

- hosts: all

  tasks:

    - debug:
        msg: "Copy {{ file }} to {{ item }}"
      loop: "{{ ansible_play_hosts_all }}"
      loop_control:
        extended: true
      vars:
        index: "{{ '%02d' % ansible_loop.index }}"
        file: "/kafka_certification/kafka.server{{ index }}.keystore.jk"
      run_once: true
      delegate_to: localhost

gives (abridged)

  msg: Copy /kafka_certification/kafka.server01.keystore.jk to app01
  msg: Copy /kafka_certification/kafka.server02.keystore.jk to app02
  msg: Copy /kafka_certification/kafka.server03.keystore.jk to app03
  msg: Copy /kafka_certification/kafka.server04.keystore.jk to app04
  msg: Copy /kafka_certification/kafka.server05.keystore.jk to app05
  msg: Copy /kafka_certification/kafka.server06.keystore.jk to app06

There is a simpler approach. The play below gives the same result without iteration

- hosts: all

  tasks:

    - debug:
        msg: "Copy {{ file }} to {{ inventory_hostname }}"
      vars:
        idx: "{{ ansible_play_hosts_all.index(inventory_hostname) + 1 }}"
        index: "{{ '%02d' % idx|int }}"
        file: "/kafka_certification/kafka.server{{ index }}.keystore.jk"

This option complies with the Ansible context. See Plays:

... playbook object maps managed nodes (hosts) to tasks.

Q: "Copy file to all nodes. Use loop.index on inventory host group [all_servers]"

A: In this particular case the play below gives the same result

- hosts: all_servers

  tasks:

    - debug:
        msg: "Copy {{ file }} to {{ inventory_hostname }}"
      vars:
        idx: "{{ groups.all_servers.index(inventory_hostname) + 1 }}"
        index: "{{ '%02d' % idx|int }}"
        file: "/kafka_certification/kafka.server{{ index }}.keystore.jk"

^{PLAY [all_servers] ****************************************************************************

TASK [debug] **********************************************************************************
ok: [app02] =>
msg: Copy /kafka_certification/kafka.server02.keystore.jk to app02
ok: [app01] =>
msg: Copy /kafka_certification/kafka.server01.keystore.jk to app01
ok: [app04] =>
msg: Copy /kafka_certification/kafka.server04.keystore.jk to app04
ok: [app03] =>
msg: Copy /kafka_certification/kafka.server03.keystore.jk to app03
ok: [app05] =>
msg: Copy /kafka_certification/kafka.server05.keystore.jk to app05
ok: [app06] =>
msg: Copy /kafka_certification/kafka.server06.keystore.jk to app06

PLAY RECAP ************************************************************************************
app01: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
app02: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
app03: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
app04: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
app05: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
app06: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0}

How to output loop.index in jinja

1 Answers1