feat: Adds Icinga2 Provider

[DMMutua]

Closes #3810

📑 Description

Adds new Icinga2 Provider for Integration with Icinga2 Monitoring System. Implementation Entails:-

• [x] Basic auth with Icinga2 API
• [x] Alert fetch and mapping to Keep alert format
• [x] Icinga2 states mapping to Keep alert severities.
• [x] Alert acknowledgment and removal
• [x] Scope validations for r/w permissions

✅ Checks

• [x] My pull request adheres to the code style of this project
• [x] My code requires changes to the documentation
• [ ] I have updated the documentation as required
• [x] All the tests have passed

ℹ Additional Information

• Follows [BaseProvider]
• Uses requests session for connection pooling.
• SSL verification config.
• Alert Ids are of format {hostname}_{servicename}

/claim #3810

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[talboren]

@DMMutua it seems like the PR is missing the icon and documentation for Icinga, can you add it? Check out this for inspiration: https://github.com/keephq/keep/pull/3930

Also - doesn't Icinga support webhooks for receiving alerts? Pushing is always better then pulling. Check out Icinga's event handlers: https://icinga.com/docs/icinga-2/latest/doc/03-monitoring-basics/#event-commands

[DMMutua]

@DMMutua it seems like the PR is missing the icon and documentation for Icinga, can you add it? Check out this for inspiration: https://github.com/keephq/keep/pull/3930

Also - doesn't Icinga support webhooks for receiving alerts? Pushing is always better then pulling. Check out Icinga's event handlers: https://icinga.com/docs/icinga-2/latest/doc/03-monitoring-basics/#event-commands

@talboren okay. Working on it ...

[talboren]

@DMMutua it seems like the PR is missing the icon and documentation for Icinga, can you add it? Check out this for inspiration: #3930 Also - doesn't Icinga support webhooks for receiving alerts? Pushing is always better then pulling. Check out Icinga's event handlers: https://icinga.com/docs/icinga-2/latest/doc/03-monitoring-basics/#event-commands

@talboren okay. Working on it ...

for now, I'm closing the PR. looking forward to re-opening it once you had a chance to fix those issues :)

[DMMutua]

hi @talboren. I have had a chance to work on all issues you referenced above and I would like the PR re-opened to fix them

[talboren]

@DMMutua feel free to re-open the pr!

[DMMutua]

@tal I just opted to raise another new pr at #4728 I will be waiting for your review on the same