Add Debouncing Middleware Feature to Pode

[mdaneri]

Description:

This pull request introduces a new middleware feature to Pode: Debouncing. The Debouncing middleware helps control and limit repeated client requests to specific endpoints within a specified timeout window. This feature enhances server performance by throttling excessive requests and prevents resource overloading.

Key Features:

1. Debounce Timeout:

   • Prevents repeated requests from the same client within a configurable timeout window.
   • Returns a 429 Too Many Requests response when requests exceed the defined threshold.

2. Cleanup Mechanism:

   • Includes a timer that periodically cleans up expired debounce entries to ensure efficient memory usage.
   • Configurable cleanup interval for flexibility in different server scenarios.

3. Expiration Logic:

   • Allows configuration of expiration times for debounce entries to prevent stale or unused data from accumulating.

4. Thread-Safe Implementation:

   • Uses ConcurrentDictionary for managing debounce entries, ensuring thread safety in high-concurrency environments.

5. Enable and Disable Functionality:

   • Add-PodeDebounce to enable debouncing middleware with customizable options.
   • Remove-PodeDebounce to disable the middleware and associated timers when no longer needed.

Example Usage:

# Add debouncing with a 500ms timeout
Add-PodeDebounce -DebounceTimeoutMilliseconds 500

# Add advanced configuration with cleanup and expiration
Add-PodeDebounce -DebounceTimeoutMilliseconds 500 -CleanupIntervalSeconds 300 -ExpirationSeconds 60

# Remove debouncing
Remove-PodeDebounce

Purpose:

This feature provides server administrators with a powerful tool to manage client request rates effectively, avoiding potential denial-of-service issues caused by excessive or rapid-fire requests.

Linked Issues:

• debounce for get/post request #1462

[Badgerati]

I might have another approach for this; I've wanted to overhaul Add-PodeLimitRule and make it more dynamic for quite some time - rather that it being restrictive to just "IP" or just "Route".

I'm just putting something together for it now, and I'll push it in the next couple days.

[Badgerati]

Pushed under #1469, to mimic the same functionality of debouncing, this should work:

# Only allow an IP to hit a Route once every 60secs
Add-PodeLimitRateRule -Name 'Example' -Limit 1 -Timeout 60 -Component @(
    New-PodeLimitIPComponent
    New-PodeLimitRouteComponent
)

Or, to add in GET/POST from #1462:

# Only allow an IP to hit a GET/POST Route once every 60secs
Add-PodeLimitRateRule -Name 'Example' -Limit 1 -Timeout 60 -Component @(
    New-PodeLimitIPComponent
    New-PodeLimitRouteComponent
    New-PodeLimitMethodComponent -Method Get, Post
)