Problem with delegate_to to group in inventory

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1

Hi guys.

I’m trying to use the “delegate_to”, to only run a certain task to a group in my inventory.

inventory file:

[zabbixprimary]
localhost ansible_port=2235 # zabbix primary

[zabbixslave]
localhost ansible_port=2236 # zabbix secondary

[zabbix:children]
zabbixprimary
zabbixslave

main.yml:

  • name: Setup Zabbix and Grafana
    hosts: zabbix
    become: yes
    become_user: root
    gather_facts: False

task.yml:

  • name: Enable Zabbix HA - primary
    run_once: true
    ansible.builtin.shell: sed -i ‘s/# HANodeName=/HANodeName={{ hostname_secondary }}/g’ /etc/zabbix/zabbix_server.conf && sed -i ‘s/# NodeAddress=localhost:10051/NodeAddress={{ hostname_primary }}:10051/g’ /etc/zabbix/zabbix_server.conf
    when: not ansible_check_mode and zabbix_ha
    delegate_to: zabbixprimary

  • name: Enable Zabbix HA - secondary
    run_once: true
    ansible.builtin.shell: sed -i ‘s/# NodeAddress=localhost:10051/NodeAddress={{ hostname_secondary }}:10051/g’ /etc/zabbix/zabbix_server.conf
    when: not ansible_check_mode and zabbix_ha
    delegate_to: zabbixslave

But I get an error:
fatal: [localhost → zabbixprimary]: UNREACHABLE! => {“changed”: false, “msg”: “Failed to connect to the host via ssh: ssh: Could not resolve hostname zabbixprimary: nodename nor servname provided, or not known”, “unreachable”: true}

Am i doing it right? I couldn’t find much information online about how to achieve this.

Thanks!
Lucas

2

My bad… managed to get it working by using: inventory_hostname in groups[‘zabbixslave’]

Cheers!

3

Well… Didn’t quite get it, actually.

My task.yml looks like this:

  • name: Enable Zabbix HA - primary
    ansible.builtin.shell: sed -i ‘s/# HANodeName=/HANodeName={{ hostname_secondary }}/g’ /etc/zabbix/zabbix_server.conf && sed -i ‘s/# NodeAddress=localhost:10051/NodeAddress={{ hostname_primary }}:10051/g’ /etc/zabbix/zabbix_server.conf
    when: inventory_hostname in groups[‘zabbixprimary’] and zabbix_ha and not ansible_check_mode
    delegate_to: “{{ item }}”
    delegate_facts: true
    with_items: “{{ groups[‘zabbixprimary’] }}”

  • name: Enable Zabbix HA - secondary
    ansible.builtin.shell: sed -i ‘s/# NodeAddress=localhost:10051/NodeAddress={{ hostname_secondary }}:10051/g’ /etc/zabbix/zabbix_server.conf
    when: inventory_hostname in groups[‘zabbixslave’] and zabbix_ha and not ansible_check_mode
    delegate_to: “{{ item }}”
    delegate_facts: true
    with_items: “{{ groups[‘zabbixslave’] }}”

However, looks like only one of the hosts is updated. Am I doing it right?

4

>>
>> inventory file:
>> [zabbixprimary]
>> localhost ansible_port=2235 # zabbix primary
>>
>> [zabbixslave]
>> localhost ansible_port=2236 # zabbix secondary
>>
>> [zabbix:children]
>> zabbixprimary
>> zabbixslave
>>
>> - name: Enable Zabbix HA - primary
>> ansible.builtin.shell: sed -i 's/# HANodeName=/HANodeName={{
>> ...
>> delegate_to: zabbixprimary
>>
>> fatal: [localhost -> zabbixprimary]: UNREACHABLE! => {"changed": false,
>> "msg": "Failed to connect to the host via ssh: ssh: Could not resolve
>> hostname zabbixprimary: nodename nor servname provided, or not known",
>> "unreachable": true}

It's not possible to delegate a task to a group. Delegate to a host
instead. Change the inventory. For example

  > cat hosts
  zabbixprimary ansible_host=localhost ansible_port=2235
  zabbixslave ansible_host=localhost ansible_port=2236

  [zabbix]
  zabbixprimary
  zabbixslave

You should be able to delegate to the hosts. For example

  - hosts: zabbix
    tasks:
      - shell: echo OK
        delegate_to: zabbixprimary
        run_once: true
      - shell: echo OK
        delegate_to: zabbixslave
        run_once: true

should work as expected

  TASK [shell] *********************************************
  changed: [zabbixprimary -> zabbixprimary]

  TASK [shell] *********************************************
  changed: [zabbixprimary -> zabbixslave]

5

Interesting! And can I use the “delegate_to” command to more than one host at a time?

Cheers!
Lucas

6

It’s not possible to delegate a task to a group. Delegate to a host
instead. Change the inventory. For example

cat hosts
zabbixprimary ansible_host=localhost ansible_port=2235
zabbixslave ansible_host=localhost ansible_port=2236

[zabbix]
zabbixprimary
zabbixslave

You should be able to delegate to the hosts. For example

  • hosts: zabbix
    tasks:
  • shell: echo OK
    delegate_to: zabbixprimary
    run_once: true
  • shell: echo OK
    delegate_to: zabbixslave
    run_once: true

should work as expected

TASK [shell] *********************************************
changed: [zabbixprimary → zabbixprimary]

TASK [shell] *********************************************
changed: [zabbixprimary → zabbixslave]

–
Vladimir Botka

Interesting! And can I use the “delegate_to” command to more than one host at a time?

Yes, I can! Using:

delegate_to: “{{ item }}”
delegate_facts: true
loop:

  • zabbixslave
  • zabbixslave02
7

[zabbix]
zabbixprimary ansible_host=IP_ADDRESS ansible_port=PORT
zabbixslave ansible_host=IP_ADDRESS ansible_port=PORT

[zabbix:vars]
ansible_python_interpreter=/usr/bin/python3
ansible_user=login
ansible_password=password

Good luck.

среда, 15 декабря 2021 г. в 09:06:17 UTC+3, drum....@gmail.com:

8

BTW, your initial problem was that you had

delegate_to: zabbixprimary
where you needed

delegate_to: “{{ zabbixprimary }}”

But you’re well past that now.

As my old CompSci prof. used to say, “Don’t let these little things confuse you. Try to get confused on a higher level.”