Mock Kubernetes HPA CPU Scaling in Python

import random
import time


def simulate_cpu_utilization(target_utilization=50, samples=10):
    """Simulate CPU utilization readings for HPA mock."""
    utilizations = []
    for _ in range(samples):
        # Simulate fluctuating CPU with random noise around target
        current = target_utilization + random.uniform(-20, 20)
        # Clamp between 0 and 100
        current = max(0.0, min(100.0, current))
        utilizations.append(round(current, 2))
    return utilizations


def calculate_hpa_replicas(current_replicas, current_utilization, target_utilization):
    """Calculate desired replicas similar to Kubernetes HPA formula."""
    if current_utilization == 0:
        return max(1, current_replicas)
    ratio = current_utilization / target_utilization
    desired_replicas = current_replicas * ratio
    return max(1, int(desired_replicas + 0.5))  # round up


if __name__ == "__main__":
    replicas = 3
    target = 50
    cpu_samples = simulate_cpu_utilization(target, samples=5)
    print(f"CPU samples: {cpu_samples}")
    for cpu in cpu_samples:
        desired = calculate_hpa_replicas(replicas, cpu, target)
        print(f"CPU={cpu}% -> replicas: {desired}")
        replicas = desired