Rename linux collectors for build constraints.

collector/diskstats_linux.go

@@ -0,0 +1,215 @@
+// +build !nodiskstats
+
+package collector
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/log"
+)
+
+const (
+	procDiskStats = "/proc/diskstats"
+	diskSubsystem = "disk"
+)
+
+var (
+	ignoredDevices = flag.String("collector.diskstats.ignored-devices", "^(ram|loop|fd|(h|s|v|xv)d[a-z])\\d+$", "Regexp of devices to ignore for diskstats.")
+)
+
+type diskstatsCollector struct {
+	ignoredDevicesPattern *regexp.Regexp
+	metrics               []prometheus.Collector
+}
+
+func init() {
+	Factories["diskstats"] = NewDiskstatsCollector
+}
+
+// Takes a prometheus registry and returns a new Collector exposing
+// disk device stats.
+func NewDiskstatsCollector() (Collector, error) {
+	var diskLabelNames = []string{"device"}
+
+	return &diskstatsCollector{
+		ignoredDevicesPattern: regexp.MustCompile(*ignoredDevices),
+		// Docs from https://www.kernel.org/doc/Documentation/iostats.txt
+		metrics: []prometheus.Collector{
+			prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Namespace: Namespace,
+					Subsystem: diskSubsystem,
+					Name:      "reads_completed",
+					Help:      "The total number of reads completed successfully.",
+				},
+				diskLabelNames,
+			),
+			prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Namespace: Namespace,
+					Subsystem: diskSubsystem,
+					Name:      "reads_merged",
+					Help:      "The number of reads merged. See https://www.kernel.org/doc/Documentation/iostats.txt.",
+				},
+				diskLabelNames,
+			),
+			prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Namespace: Namespace,
+					Subsystem: diskSubsystem,
+					Name:      "sectors_read",
+					Help:      "The total number of sectors read successfully.",
+				},
+				diskLabelNames,
+			),
+			prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Namespace: Namespace,
+					Subsystem: diskSubsystem,
+					Name:      "read_time_ms",
+					Help:      "The total number of milliseconds spent by all reads.",
+				},
+				diskLabelNames,
+			),
+			prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Namespace: Namespace,
+					Subsystem: diskSubsystem,
+					Name:      "writes_completed",
+					Help:      "The total number of writes completed successfully.",
+				},
+				diskLabelNames,
+			),
+			prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Namespace: Namespace,
+					Subsystem: diskSubsystem,
+					Name:      "writes_merged",
+					Help:      "The number of writes merged. See https://www.kernel.org/doc/Documentation/iostats.txt.",
+				},
+				diskLabelNames,
+			),
+			prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Namespace: Namespace,
+					Subsystem: diskSubsystem,
+					Name:      "sectors_written",
+					Help:      "The total number of sectors written successfully.",
+				},
+				diskLabelNames,
+			),
+			prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Namespace: Namespace,
+					Subsystem: diskSubsystem,
+					Name:      "write_time_ms",
+					Help:      "This is the total number of milliseconds spent by all writes.",
+				},
+				diskLabelNames,
+			),
+			prometheus.NewGaugeVec(
+				prometheus.GaugeOpts{
+					Namespace: Namespace,
+					Subsystem: diskSubsystem,
+					Name:      "io_now",
+					Help:      "The number of I/Os currently in progress.",
+				},
+				diskLabelNames,
+			),
+			prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Namespace: Namespace,
+					Subsystem: diskSubsystem,
+					Name:      "io_time_ms",
+					Help:      "Milliseconds spent doing I/Os.",
+				},
+				diskLabelNames,
+			),
+			prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Namespace: Namespace,
+					Subsystem: diskSubsystem,
+					Name:      "io_time_weighted",
+					Help:      "The weighted # of milliseconds spent doing I/Os. See https://www.kernel.org/doc/Documentation/iostats.txt.",
+				},
+				diskLabelNames,
+			),
+		},
+	}, nil
+}
+
+func (c *diskstatsCollector) Update(ch chan<- prometheus.Metric) (err error) {
+	diskStats, err := getDiskStats()
+	if err != nil {
+		return fmt.Errorf("couldn't get diskstats: %s", err)
+	}
+
+	for dev, stats := range diskStats {
+		if c.ignoredDevicesPattern.MatchString(dev) {
+			log.Debugf("Ignoring device: %s", dev)
+			continue
+		}
+
+		if len(stats) != len(c.metrics) {
+			return fmt.Errorf("invalid line for %s for %s", procDiskStats, dev)
+		}
+
+		for k, value := range stats {
+			v, err := strconv.ParseFloat(value, 64)
+			if err != nil {
+				return fmt.Errorf("invalid value %s in diskstats: %s", value, err)
+			}
+
+			if counter, ok := c.metrics[k].(*prometheus.CounterVec); ok {
+				counter.WithLabelValues(dev).Set(v)
+			} else if gauge, ok := c.metrics[k].(*prometheus.GaugeVec); ok {
+				gauge.WithLabelValues(dev).Set(v)
+			} else {
+				return fmt.Errorf("unexpected collector %d", k)
+			}
+		}
+	}
+	for _, c := range c.metrics {
+		c.Collect(ch)
+	}
+	return err
+}
+
+func getDiskStats() (map[string]map[int]string, error) {
+	file, err := os.Open(procDiskStats)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	return parseDiskStats(file)
+}
+
+func parseDiskStats(r io.Reader) (map[string]map[int]string, error) {
+	var (
+		diskStats = map[string]map[int]string{}
+		scanner   = bufio.NewScanner(r)
+	)
+
+	for scanner.Scan() {
+		parts := strings.Fields(string(scanner.Text()))
+		if len(parts) < 4 { // we strip major, minor and dev
+			return nil, fmt.Errorf("invalid line in %s: %s", procDiskStats, scanner.Text())
+		}
+		dev := parts[2]
+		diskStats[dev] = map[int]string{}
+		for i, v := range parts[3:] {
+			diskStats[dev][i] = v
+		}
+	}
+
+	return diskStats, nil
+}