Ansible
Adhoc commands
Generic
ansible <hosts/groups pattern> -l <limit pattern> -m <module> -a "<module args>" -u <login user> --become --ask-become-pass
Example
ansible all -l localhost -m systemd -a "name=nginx state=restarted" -u test --become --ask-become-pass
Usecases
Filter numbers from a list of strings
sample.result_list is a list of lists containing stdout output. We want to filter some numbers from this output. To do this we first filter the correct lines by using the json_query filter. If you need to match a specific substring, you could use select("match", "<regex>") in combination with the json_query. Next we map the regex_search filter on all lines to extract the data we need. As the map filter is a Python generator object, we need to convert it to a list.
The regex (?<=\()\d+ uses a feature called positive lookbehind: (?<=\(). It matches a group before the main expression with including it in the result. In this case it matches the opening parantheses (. This feature may not be supported in your regex implementation, but in Ansible/Python it is supported. To make the regex even more specific you could add a positive lookahead ((?=\))) after the \d+ to match the closing parantheses ).
---
- hosts: localhost
vars:
sample:
result_list:
- stdout_lines:
- 'line0'
- 'line12 (2319)'
- stdout_lines:
- 'line2'
- 'line12 (2320)'
tasks:
- debug:
msg: '{{ sample.result_list | json_query("[*].stdout_lines[1]") | map("regex_search" ,"(?<=\()\d+") | list }}'