#!/bin/bash
# Debian Linux optimization script for Archipelago
# Optimizes system settings for container workloads

set -e

echo "⚡ Optimizing Debian Linux for container workloads..."

# CPU Governor - set to performance for better container performance
if [ -f /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor ]; then
    echo "performance" > /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor 2>/dev/null || true
fi

# I/O Scheduler - use none for NVMe or mq-deadline for SATA
if command -v lsblk >/dev/null 2>&1; then
    for disk in $(lsblk -d -o NAME -n); do
        if [ -f "/sys/block/$disk/queue/scheduler" ]; then
            # Prefer none (for NVMe) or mq-deadline (for SATA SSD)
            if grep -q "none" "/sys/block/$disk/queue/scheduler"; then
                echo none > "/sys/block/$disk/queue/scheduler" 2>/dev/null || true
            elif grep -q "mq-deadline" "/sys/block/$disk/queue/scheduler"; then
                echo mq-deadline > "/sys/block/$disk/queue/scheduler" 2>/dev/null || true
            fi
        fi
    done
fi

# Increase file descriptor limits
cat >> /etc/security/limits.conf <<EOF
* soft nofile 65536
* hard nofile 65536
root soft nofile 65536
root hard nofile 65536
EOF

# Optimize network settings for container networking
cat >> /etc/sysctl.d/99-archipelago.conf <<EOF
# Container networking optimizations
net.core.somaxconn = 4096
net.ipv4.tcp_max_syn_backlog = 4096
net.core.netdev_max_backlog = 5000
net.ipv4.ip_local_port_range = 1024 65535

# Container storage optimizations
vm.swappiness = 10
vm.dirty_ratio = 15
vm.dirty_background_ratio = 5

# Enable IP forwarding for containers
net.ipv4.ip_forward = 1
EOF

# Apply sysctl settings
sysctl --system >/dev/null 2>&1 || true

echo "✅ Debian optimization complete!"