Nagios XI downtime, use different list of servers every time

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1

Hello all!

I’m trying to automate servers being put into downtime mode in Nagios XI (2024R1.1.3). I want to use an inventory file that changes, using a file that just has a list of servers generated the day before the patching event. I don’t want to have to update the /etc/ansible/hosts file every time, there will be 100’s of servers in each region.

For example:
dev_file:
server1
server 2

prod_file:
server3
server4

I’m using ansible 2.9.27 on RedHat 8.10

Thanks!

2

If you have control over the file generation, you can format the files like this

# assume this is called dev_file
all:
  hosts:
    server1:
    server2:

then run ansible-playbook -i dev_file ......

If you dont have control over the file, you can use a quick and dirty bash command:
ansible-playbook -i "$(cat dev_file | tr '\n' ', ')" ......

You can also write a custom inventory plugin. As an example, use the python script below. The name my_plugin can be whatever makes sense for you, just make sure the filename matches.
The file should be placed somewhere on the search path, as described here
https://docs.ansible.com/ansible/latest/reference_appendices/config.html#default-inventory-plugin-path

# my_plugin.py
from ansible.plugins.inventory import BaseInventoryPlugin

class InventoryModule(BaseInventoryPlugin):

    NAME = 'my_plugin'

    def parse(self, inventory, loader, path, cache=True):
        super(InventoryModule, self).parse(inventory, loader, path)
        with open(path, 'r') as f:
            for line in f:
                self.inventory.add_host(f)

Then you can run ansible-playbook -i dev_file .... and it will read the file automatically.

3

To be clear, this is assuming the files look like this

server1
server2
server3

If the format is different then my examples wont quite work.