[wip] add missing sysfs bits to netlink exporter

collector/netclass_linux.go

@@ -64,10 +64,7 @@ func NewNetClassCollector(logger log.Logger) (Collector, error) {
 }
 
 func (c *netClassCollector) Update(ch chan<- prometheus.Metric) error {
-	if *netclassNetlink {
-		return c.netClassRTNLUpdate(ch)
-	}
-	return c.netClassSysfsUpdate(ch)
+	return c.netClassRTNLUpdate(ch)
 }
 
 func (c *netClassCollector) netClassSysfsUpdate(ch chan<- prometheus.Metric) error {

collector/netclass_rtnl_linux.go

@@ -17,14 +17,19 @@
 package collector
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"io/fs"
+	"os"
+	"path/filepath"
+	"strconv"
 
 	"github.com/go-kit/log/level"
 	"github.com/jsimonetti/rtnetlink"
 	"github.com/mdlayher/ethtool"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/procfs/sysfs"
 	"gopkg.in/alecthomas/kingpin.v2"
 )
 
@@ -57,14 +62,27 @@ func (c *netClassCollector) netClassRTNLUpdate(ch chan<- prometheus.Metric) erro
 		}
 	}
 
+	// Get most attributes from Netlink
 	lMsgs, err := c.getNetClassInfoRTNL()
 	if err != nil {
 		return fmt.Errorf("could not get net class info: %w", err)
 	}
+
+	relevantLinks := make([]rtnetlink.LinkMessage, 0, len(lMsgs))
 	for _, msg := range lMsgs {
-		if c.ignoredDevicesPattern.MatchString(msg.Attributes.Name) {
-			continue
+		if !c.ignoredDevicesPattern.MatchString(msg.Attributes.Name) {
+			relevantLinks = append(relevantLinks, msg)
 		}
+	}
+
+	// Read sysfs for attributes that Netlink doesn't expose
+	sysfsAttrs, err := getSysfsAttributes(relevantLinks)
+	if err != nil {
+		return fmt.Errorf("could not get sysfs device info: %w", err)
+	}
+
+	// Parse all the info and update metrics
+	for _, msg := range relevantLinks {
 		upDesc := prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, c.subsystem, "up"),
 			"Value is 1 if operstate is 'up', 0 otherwise.",
@@ -96,12 +114,16 @@ func (c *netClassCollector) netClassRTNLUpdate(ch chan<- prometheus.Metric) erro
 			duplex = lm.Duplex.String()
 		}
 
+		ifaceInfo := sysfsAttrs[msg.Attributes.Name]
+
 		ch <- prometheus.MustNewConstMetric(infoDesc, prometheus.GaugeValue, infoValue, msg.Attributes.Name, msg.Attributes.Address.String(), msg.Attributes.Broadcast.String(), duplex, operstateStr[int(msg.Attributes.OperationalState)], ifalias)
 
+		pushMetric(ch, c.getFieldDesc("address_assign_type"), "address_assign_type", ifaceInfo.AddrAssignType, prometheus.GaugeValue, msg.Attributes.Name)
 		pushMetric(ch, c.getFieldDesc("carrier"), "carrier", msg.Attributes.Carrier, prometheus.GaugeValue, msg.Attributes.Name)
 		pushMetric(ch, c.getFieldDesc("carrier_changes_total"), "carrier_changes_total", msg.Attributes.CarrierChanges, prometheus.CounterValue, msg.Attributes.Name)
 		pushMetric(ch, c.getFieldDesc("carrier_up_changes_total"), "carrier_up_changes_total", msg.Attributes.CarrierUpCount, prometheus.CounterValue, msg.Attributes.Name)
 		pushMetric(ch, c.getFieldDesc("carrier_down_changes_total"), "carrier_down_changes_total", msg.Attributes.CarrierDownCount, prometheus.CounterValue, msg.Attributes.Name)
+		pushMetric(ch, c.getFieldDesc("device_id"), "device_id", ifaceInfo.DevID, prometheus.GaugeValue, msg.Attributes.Name)
 		pushMetric(ch, c.getFieldDesc("flags"), "flags", msg.Flags, prometheus.GaugeValue, msg.Attributes.Name)
 		pushMetric(ch, c.getFieldDesc("iface_id"), "iface_id", msg.Index, prometheus.GaugeValue, msg.Attributes.Name)
 		pushMetric(ch, c.getFieldDesc("iface_link_mode"), "iface_link_mode", msg.Attributes.LinkMode, prometheus.GaugeValue, msg.Attributes.Name)
@@ -117,6 +139,7 @@ func (c *netClassCollector) netClassRTNLUpdate(ch chan<- prometheus.Metric) erro
 		}
 
 		pushMetric(ch, c.getFieldDesc("mtu_bytes"), "mtu_bytes", msg.Attributes.MTU, prometheus.GaugeValue, msg.Attributes.Name)
+		pushMetric(ch, c.getFieldDesc("name_assign_type"), "name_assign_type", ifaceInfo.NameAssignType, prometheus.GaugeValue, msg.Attributes.Name)
 		pushMetric(ch, c.getFieldDesc("net_dev_group"), "net_dev_group", msg.Attributes.NetDevGroup, prometheus.GaugeValue, msg.Attributes.Name)
 		pushMetric(ch, c.getFieldDesc("transmit_queue_length"), "transmit_queue_length", msg.Attributes.TxQueueLen, prometheus.GaugeValue, msg.Attributes.Name)
 		pushMetric(ch, c.getFieldDesc("protocol_type"), "protocol_type", msg.Type, prometheus.GaugeValue, msg.Attributes.Name)
@@ -186,3 +209,62 @@ func (c *netClassCollector) getLinkModes() ([]*ethtool.LinkMode, error) {
 
 	return lms, err
 }
+
+// getSysfsAttributes reads attributes that are absent from netlink but provided
+// by sysfs.
+func getSysfsAttributes(links []rtnetlink.LinkMessage) (sysfs.NetClass, error) {
+	netClass := sysfs.NetClass{}
+	for _, msg := range links {
+		var err error
+		interfaceClass := sysfs.NetClassIface{}
+		ifName := msg.Attributes.Name
+
+		// These three attributes hold a device-specific lock when
+		// accessed, not the RTNL lock, so they are much less impactful
+		// than reading most of the other attributes from sysfs.
+		interfaceClass.AddrAssignType, err = getSysfsAttrAsInt64(ifName, "addr_assign_type")
+		if err != nil {
+			return nil, err
+		}
+		interfaceClass.DevID, err = getSysfsAttrAsInt64(ifName, "dev_id")
+		if err != nil {
+			return nil, err
+		}
+		interfaceClass.NameAssignType, err = getSysfsAttrAsInt64(ifName, "name_assign_type")
+		if err != nil {
+			return nil, err
+		}
+
+		netClass[ifName] = interfaceClass
+	}
+	return netClass, nil
+}
+
+func getSysfsAttrAsInt64(linkName, attr string) (*int64, error) {
+	name := filepath.Join("/sys", "class", "net", linkName, attr)
+	data, err := os.ReadFile(name)
+	if err != nil {
+		var perr *fs.PathError
+		// Ignore certain errors we know aren't fatal; same as
+		// prometheus's sysfs class does
+		if os.IsNotExist(err) || os.IsPermission(err) {
+			return nil, nil
+		} else if errors.As(err, &perr) {
+			realErr := perr.Unwrap()
+			if realErr.Error() == "operation not supported" || realErr.Error() == "invalid argument" {
+				return nil, nil
+			}
+		}
+		return nil, fmt.Errorf("failed to read file %q: %w", name, err)
+	}
+
+	// base 0 automatically handles number type prefixes (hex, octal, etc)
+	const base = 0
+	val, err := strconv.ParseInt(string(bytes.TrimSpace(data)), base, 64)
+	if err != nil {
+		// Ignore the error; can't do much with it and an error
+		// parsing a single attribute shouldn't stop parsing others
+		return nil, nil
+	}
+	return &val, nil
+}