feat(hwmon): implement device reader for architectures with hwmon sensors

cmd/kepler/main.go

@@ -259,6 +259,26 @@ func createCPUMeter(logger *slog.Logger, cfg *config.Config) (device.CPUPowerMet
 		return device.NewFakeCPUMeter(fake.Zones, device.WithFakeLogger(logger))
 	}
 
+	// Launch hwmon if enabled (experimental feature)
+	if cfg.IsFeatureEnabled(config.ExperimentalHwmonFeature) {
+		hwmon := cfg.Experimental.Hwmon
+
+		if len(hwmon.Zones) > 0 {
+			logger.Info("hwmon zones are filtered", "zones-enabled", hwmon.Zones)
+		}
+
+		if len(hwmon.Chips) > 0 {
+			logger.Info("hwmon chips/sensors are filtered", "sensors-enabled", hwmon.Chips)
+		}
+
+		return device.NewHwmonPowerMeter(
+			cfg.Host.SysFS,
+			device.WithHwmonLogger(logger),
+			device.WithChipFilter(hwmon.Chips),
+			device.WithHwmonZoneFilter(hwmon.Zones),
+		)
+	}
+
 	if len(cfg.Rapl.Zones) > 0 {
 		logger.Info("rapl zones are filtered", "zones-enabled", cfg.Rapl.Zones)
 	}

config/config.go

@@ -22,6 +22,9 @@ import (
 type Feature string
 
 const (
+	// ExperimentalHwmonFeature represents the hwmon power monitoring feature
+	ExperimentalHwmonFeature Feature = "hwmon"
+
 	// ExperimentalRedfishFeature represents the Redfish BMC power monitoring feature
 	ExperimentalRedfishFeature Feature = "redfish"
 
@@ -51,6 +54,13 @@ type (
 		Zones []string `yaml:"zones"`
 	}
 
+	// Hwmon configuration (Set in Experimental)
+	Hwmon struct {
+		Enabled *bool    `yaml:"enabled"` // Development mode settings (sensor detection should be set based on architecture in future)
+		Zones   []string `yaml:"zones"`
+		Chips   []string `yaml:"chips"`
+	}
+
 	// Development mode settings; disabled by default
 	Dev struct {
 		FakeCpuMeter struct {
@@ -127,6 +137,7 @@ type (
 	// Experimental contains experimental features (no stability guarantees)
 	Experimental struct {
 		Platform Platform `yaml:"platform"`
+		Hwmon    Hwmon    `yaml:"hwmon"`
 	}
 
 	Config struct {
@@ -231,6 +242,11 @@ const (
 	ExperimentalPlatformRedfishNodeNameFlag = "experimental.platform.redfish.node-name"
 	ExperimentalPlatformRedfishConfigFlag   = "experimental.platform.redfish.config-file"
 
+	// Experimental Hwmon flags
+	ExperimentalHwmonEnabledFlag = "experimental.hwmon.enabled"
+	ExperimentalHwmonZonesFlag   = "experimental.hwmon.zones"
+	ExperimentalHwmonChipsFlag   = "experimental.hwmon.chips"
+
 // WARN:  dev settings shouldn't be exposed as flags as flags are intended for end users
 )
 
@@ -381,6 +397,11 @@ func RegisterFlags(app *kingpin.Application) ConfigUpdaterFn {
 	redfishNodeName := app.Flag(ExperimentalPlatformRedfishNodeNameFlag, "Node name for experimental Redfish platform power monitoring").String()
 	redfishConfig := app.Flag(ExperimentalPlatformRedfishConfigFlag, "Path to experimental Redfish BMC configuration file").String()
 
+	// experimental hwmon
+	hwmonEnabled := app.Flag(ExperimentalHwmonEnabledFlag, "Enable experimental hwmon power monitoring").Default("false").Bool()
+	hwmonZones := app.Flag(ExperimentalHwmonZonesFlag, "Hwmon zone filter (power labels to monitor)").Strings()
+	hwmonChips := app.Flag(ExperimentalHwmonChipsFlag, "Hwmon chip filter (chip names to monitor)").Strings()
+
 	return func(cfg *Config) error {
 		// Logging settings
 		if flagsSet[LogLevelFlag] {
@@ -448,6 +469,11 @@ func RegisterFlags(app *kingpin.Application) ConfigUpdaterFn {
 			return err
 		}
 
+		// Apply experimental hwmon settings
+		if err := applyHwmonConfig(cfg, flagsSet, hwmonEnabled, hwmonZones, hwmonChips); err != nil {
+			return err
+		}
+
 		cfg.sanitize()
 		return cfg.Validate()
 	}
@@ -524,6 +550,59 @@ func resolveRedfishNodeName(redfish *Redfish, kubeNodeName string) error {
 	return nil
 }
 
+// applyHwmonConfig applies Hwmon configuration flags
+func applyHwmonConfig(cfg *Config, flagsSet map[string]bool, enabled *bool, zones *[]string, chips *[]string) error {
+	// Early exit if no hwmon flags are set and config file does not have experimental section
+	if !hasHwmonFlags(flagsSet) && cfg.Experimental == nil {
+		return nil
+	}
+
+	// At this point, either hwmon flags are set or config file has experimental section
+	// so ensure experimental section exists
+	if cfg.Experimental == nil {
+		cfg.Experimental = &Experimental{
+			Hwmon: defaultHwmonConfig(),
+		}
+	}
+
+	hwmon := &cfg.Experimental.Hwmon
+
+	// Apply flag values
+	applyHwmonFlags(hwmon, flagsSet, enabled, zones, chips)
+
+	return nil
+}
+
+// hasHwmonFlags returns true if any hwmon experimental flags are set
+func hasHwmonFlags(flagsSet map[string]bool) bool {
+	return flagsSet[ExperimentalHwmonEnabledFlag] ||
+		flagsSet[ExperimentalHwmonZonesFlag] ||
+		flagsSet[ExperimentalHwmonChipsFlag]
+}
+
+func defaultHwmonConfig() Hwmon {
+	return Hwmon{
+		Enabled: ptr.To(false),
+		Zones:   []string{},
+		Chips:   []string{},
+	}
+}
+
+// applyHwmonFlags applies flag values to hwmon config
+func applyHwmonFlags(hwmon *Hwmon, flagsSet map[string]bool, enabled *bool, zones *[]string, chips *[]string) {
+	if flagsSet[ExperimentalHwmonEnabledFlag] {
+		hwmon.Enabled = enabled
+	}
+
+	if flagsSet[ExperimentalHwmonZonesFlag] {
+		hwmon.Zones = *zones
+	}
+
+	if flagsSet[ExperimentalHwmonChipsFlag] {
+		hwmon.Chips = *chips
+	}
+}
+
 // resolveNodeName resolves the node name using the following precedence:
 // 1. CLI flag / config.yaml (--experimental.platform.redfish.node-name)
 // 2. Kubernetes node name
@@ -556,6 +635,11 @@ func (c *Config) IsFeatureEnabled(feature Feature) bool {
 			return false
 		}
 		return ptr.Deref(c.Experimental.Platform.Redfish.Enabled, false)
+	case ExperimentalHwmonFeature:
+		if c.Experimental == nil {
+			return false
+		}
+		return ptr.Deref(c.Experimental.Hwmon.Enabled, false)
 	case PrometheusFeature:
 		return ptr.Deref(c.Exporter.Prometheus.Enabled, false)
 	case StdoutFeature:
@@ -578,6 +662,11 @@ func (c *Config) experimentalFeatureEnabled() bool {
 		return true
 	}
 
+	// Check if Hwmon is enabled
+	if ptr.Deref(c.Experimental.Hwmon.Enabled, false) {
+		return true
+	}
+
 	// Add checks for future experimental features here
 
 	return false
@@ -609,6 +698,14 @@ func (c *Config) sanitize() {
 	c.Experimental.Platform.Redfish.NodeName = strings.TrimSpace(c.Experimental.Platform.Redfish.NodeName)
 	c.Experimental.Platform.Redfish.ConfigFile = strings.TrimSpace(c.Experimental.Platform.Redfish.ConfigFile)
 
+	// Sanitize Hwmon fields
+	for i := range c.Experimental.Hwmon.Zones {
+		c.Experimental.Hwmon.Zones[i] = strings.TrimSpace(c.Experimental.Hwmon.Zones[i])
+	}
+	for i := range c.Experimental.Hwmon.Chips {
+		c.Experimental.Hwmon.Chips[i] = strings.TrimSpace(c.Experimental.Hwmon.Chips[i])
+	}
+
 	// If all experimental features are disabled, set experimental to nil to hide it
 	if !c.experimentalFeatureEnabled() {
 		c.Experimental = nil