Pulse/internal/monitoring/monitor_cluster_helpers.go

package monitoring

import (
	"net"
	"net/url"
	"strings"

	"github.com/rcourtman/pulse-go-rewrite/internal/config"
)

func lookupClusterEndpointLabel(instance *config.PVEInstance, nodeName string) string {
	if instance == nil {
		return ""
	}

	for _, endpoint := range instance.ClusterEndpoints {
		if !strings.EqualFold(endpoint.NodeName, nodeName) {
			continue
		}

		if host := strings.TrimSpace(endpoint.Host); host != "" {
			if label := normalizeEndpointHost(host); label != "" && !isLikelyIPAddress(label) {
				return label
			}
		}

		if nodeNameLabel := strings.TrimSpace(endpoint.NodeName); nodeNameLabel != "" {
			return nodeNameLabel
		}

		if ip := strings.TrimSpace(endpoint.IP); ip != "" {
			return ip
		}
	}

	return ""
}

func normalizeEndpointHost(raw string) string {
	value := strings.TrimSpace(raw)
	if value == "" {
		return ""
	}

	if parsed, err := url.Parse(value); err == nil && parsed.Host != "" {
		host := parsed.Hostname()
		if host != "" {
			return host
		}
		return parsed.Host
	}

	value = strings.TrimPrefix(value, "https://")
	value = strings.TrimPrefix(value, "http://")
	value = strings.TrimSpace(value)
	if value == "" {
		return ""
	}

	if idx := strings.Index(value, "/"); idx >= 0 {
		value = strings.TrimSpace(value[:idx])
	}

	if idx := strings.Index(value, ":"); idx >= 0 {
		value = strings.TrimSpace(value[:idx])
	}

	return value
}

func isLikelyIPAddress(value string) bool {
	if value == "" {
		return false
	}

	if ip := net.ParseIP(value); ip != nil {
		return true
	}

	// Handle IPv6 with zone identifier (fe80::1%eth0)
	if i := strings.Index(value, "%"); i > 0 {
		if ip := net.ParseIP(value[:i]); ip != nil {
			return true
		}
	}

	return false
}

func ensureClusterEndpointURL(raw string) string {
	value := strings.TrimSpace(raw)
	if value == "" {
		return ""
	}

	lower := strings.ToLower(value)
	if strings.HasPrefix(lower, "http://") || strings.HasPrefix(lower, "https://") {
		return value
	}

	if _, _, err := net.SplitHostPort(value); err == nil {
		return "https://" + value
	}

	return "https://" + net.JoinHostPort(value, "8006")
}

func clusterEndpointEffectiveURL(endpoint config.ClusterEndpoint, verifySSL bool, hasFingerprint bool) string {
	// When TLS hostname verification is required (VerifySSL=true and no fingerprint),
	// prefer hostname over IP to ensure certificate CN/SAN validation works correctly.
	// When TLS is not verified (VerifySSL=false) or a fingerprint is provided (which
	// bypasses hostname checks), prefer IP to reduce DNS lookups (refs #620).
	requiresHostnameForTLS := verifySSL && !hasFingerprint

	// Use EffectiveIP() which prefers user-specified IPOverride over auto-discovered IP
	effectiveIP := endpoint.EffectiveIP()

	if requiresHostnameForTLS {
		// Prefer hostname for proper TLS certificate validation
		if endpoint.Host != "" {
			return ensureClusterEndpointURL(endpoint.Host)
		}
		if effectiveIP != "" {
			return ensureClusterEndpointURL(effectiveIP)
		}
	} else {
		// Prefer IP address to avoid excessive DNS lookups
		if effectiveIP != "" {
			return ensureClusterEndpointURL(effectiveIP)
		}
		if endpoint.Host != "" {
			return ensureClusterEndpointURL(endpoint.Host)
		}
	}
	return ""
}