Add Disk Usage Projection and Persistent CPU Usage Checks

[jpfir]

This PR introduces two new monitoring checks for use with puppet-nagios:

1. Disk Usage Projection Check (disk_projection):

   • Tracks disk usage trends and projects when a disk will fill based on current patterns.
   • Customizable thresholds for triggering alerts (default: 12 hours).
   • Allows exclusion of specific filesystem types (e.g., tmpfs).
   • Stores historical data for 7 days in /var/tmp/disk_usage_data.
   • Reduces noise by ignoring minor fluctuations below a configurable threshold.

2. Persistent CPU Usage Check (cpu_persistent):

   • Monitors CPU usage at the system level, triggering alerts only after sustained high usage.
   • Configurable warning and critical thresholds, along with duration parameters.
   • Prevents false positives caused by transient spikes in CPU activity.
   • Uses vmstat for robust CPU monitoring.

Key Changes:

• Added new Puppet classes nagios::check::disk_projection and nagios::check::cpu_persistent.
• Created and deployed respective NRPE plugins for both checks.
• Included Hiera configuration examples for easy integration and customization.
• Enhanced scripts with detailed header comments for clarity and maintainability.

Testing:

• Manually tested the scripts for both checks under simulated conditions.
• Verified proper configuration and execution via NRPE and Nagios.

Notes:
These additions provide proactive monitoring capabilities for disk and CPU usage, enhancing system reliability and reducing noise in alerts.