Score:0

Server

How to set a task to run for a specific inventory group?

Hiddai

12/12/22, 10:01 PM

The following task:

- name: Download Jfrog Artifcats
  ansible.windows.win_shell: |
    $ENV:JFROG_CLI_OFFER_CONFIG="false"
    jfrog rt download ...
  when: ???

should run only for machines that are located under center in the appservers group

---
all:
  children:
    root:
      children:
        center:
          children:
            appservers:
              hosts:
                vm1.domain.com:
            qservers:
              hosts:
                vm2.domain.com:
            dbservers:
              hosts:
                vm3.domain.com:
        mobilefarms:
          hosts:
          children:
            gateways:
              hosts:
        south:
          children:
            brooklyn:
              hosts:
                vm4.domain.com:
              children:
                clients:
                  hosts:
                    vm5.domain.com:
                    vm6.domain.com:
        north:
          children:
            new_york:
              hosts:
                vm8.domain.com:
              children:
                clients:
                  hosts:
                    vm9.domain.com:

What should I type as a condition under when in order to accomplish this? Also, What is the principle behind this configuration option?

3695

1 + 2

configuration

ansible

Semicolon

12/13/22, 12:32 AM

when: inventory_hostname in appservers Not sure what you mean by "what is the principle behind this"

Hiddai

12/13/22, 3:27 AM

@Semicolon, I want to know how am I reach to a wanted group. For example: ```appservers``` under ```center```, or ```gateways``` under ```mobilefarms```, or all machines under ```north``` and so on...

Score:2

Server

Semicolon

12/13/22, 3:58 AM

In order to use group membership in a conditional for a task, play or block, you would use the format:

when: inventory_hostname in groups["<group name>"]

Specifically to your initial question:

when: inventory_hostname in groups["appservers"]

To reach all machines under north, you would simply change it to: when: inventory_hostname in groups["north"]

In regards to your follow up clarification (specifying a group in a particular "location"), as group names must be unique in ansible, there's no need to distinguish which appservers group you're referring to, as appservers can only ever be in one location.

If you attempt to create two appservers groups, only the first one would actually be parsed by the ansible engine; any subsequent group of the same name will be ignored. So, if you were planning to (in the future) have an appservers group under north and an appservers group under south, you'll find that only members in the first group will be included.

In ansible, how we achieve this (my assumption of what you may want in the future), the ansible way to proceed is to add the hosts to multiple groups like so, and adjust your limit or conditional appropriately:

all:
  children:
    north:
      hosts:
        a.domain.com:
        b.domain.com:
    south:
      hosts:
        y.domain.com:
        z.domain.com:
    appservers:
      hosts:
        a.domain.com:
        y.domain.com:
    dbservers:
      hosts:
        b.domain.com:
        z.domain.com:

In this example, if you wanted all app servers, you would just target appservers. If you wanted only appservers in the north region, then you would set your limit on the play to north:&appservers, or alternatively use the conditional

when:
  - inventory_hostname in groups["appservers"]
  - inventory_hostname in groups["north"]

In any event, I think you might need a refresher in how inventory is structured in ansible, for that I would recommend the user guide; there are also some great resources on various training sites that can go into much greater detail.

For further information about more complex targeting using multiple groups (combinations, unions, and exclusions, etc), I suggest you review this other user guide.

On a personal note, initially I thought the setup was tedious and limited, but as I have become more familiar with using it, I actually find it more dynamic than the alternative.

0 + 5

Hiddai

12/13/22, 1:11 PM

Thank. ```when: "'appservers' in group_names"``` - This is the only format I succeed with. But, still cannot manage to focus the condition only on ```appservers``` inside ```center``` main group. I need this focus, because some labs include ```appservers``` under ```mobilefarms``` main gourp - and those machine shouldn't include the artifact...

Zeitounator

12/14/22, 8:30 PM

@Hiddai A group `Sub1` wherever you define it is **one** group. If you give several definitions of `Sub1` as a children of several parent groups. the result will be a concatenation of all host/children defined anywhere. As a result, the group `Sub1` as a children of group `A` will contain exactly the same hosts as when it is a children of group `B`. See [this question/answers](https://stackoverflow.com/questions/68746910/).

Zeitounator

12/14/22, 8:36 PM

@Semicolon: did you mean `when: inventory_hostname in groups[<group_name>]` which translates to `when: inventory_hostname in groups['appservers']` in OP's case ? Your solution cannot work as is anyway unless the user has himself defined the var `appservers` (else you get a `appservers` is undefined error). –

Hiddai

12/15/22, 7:32 AM

@Semicolon, @Zeitounator - I succeed now. After reading carefully @Semicolon's answer: "group names must be unique in ansible". when I change particullary center's ```appservers``` group to something like ```center_appservers``` name - It started to work like a magic. thanks.

Semicolon

12/16/22, 10:45 PM

@Zeitounator, indeed you are correct. I had just finished writing a series of tasks looking for a string in a hostname and just kept typing along. I've updated with the correct syntax -- using your note, but essentially just copying from an open screen I had.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: How to set a task to run for a specific inventory group?

TH: จะกำหนดงานให้เรียกใช้สำหรับกลุ่มสินค้าคงคลังเฉพาะได้อย่างไร?

RO: Cum să setați o sarcină să ruleze pentru un anumit grup de inventar?

RU: Как настроить выполнение задачи для определенной группы инвентаризации?

VI: Làm cách nào để đặt tác vụ chạy cho một nhóm khoảng không quảng cáo cụ thể?

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