如何在 Ansible playbook 中为每个客户端设置不同的环境变量

Question

I am trying to run a slightly different bash script on each ansible client, because each node needs to have a pre-set ID which has already been established. In other words: The bash script looks for an environment variable, and I need that environment variable to be individually set for each Ansible host.

I have a list of identities in a file, which correspond to the host number.

For example, in my inventory (/etc/ansible/hosts) I have:

[servergroupexample]
ansible-host-1 ansible_host=1.2.3.4
ansible-host-2 ansible_host=5.6.7.8

And in a file in /root/IDs.txt I have:

ID-asjdajdj399jad
ID-iajadijasijada

Where the line number in the IDs.txt corresponds to the ansible host number (eg ansible-host-2 should receive an environment variable which is set to the second line of IDs.txt)

So it should be possible to grep for the number in the ansible host file (eg "ansible-host-1" returns "1") and then that 1 indicates which line to read from the IDs.txt and set as the environment variable on the host itself before running the script. How do I do that?

Thanks!

Answer 1

Q: "The bash script looks for an environment variable, and I need that environment variable to be individually set for each Ansible host."

A: Run once and create a dictionary from the lists with the dict and zip filters. Then use my_ID to set the environment of the command for each host. For example

- hosts: servergroupexample
  tasks:

    - set_fact:
        my_ID: "{{ dict(groups.servergroupexample|
                        zip(lookup('file', 'IDs.txt').splitlines())) }}"
      run_once: true

    - command: echo $MYID
      register: result
      environment:
        MYID: "{{ my_ID[inventory_hostname] }}"

    - debug:
        var: result.stdout

with the inventory and IDs.txt

$ cat hosts
[servergroupexample]
test_01
test_02

$ cat IDs.txt 
ID-asjdajdj399jad
ID-iajadijasijada

gives

ok: [test_01] => 
  result.stdout: ID-asjdajdj399jad
ok: [test_02] => 
  result.stdout: ID-iajadijasijada