Move stat_linux to cpu_linux and add cpufreq stats (#548)

1 files changed, 19 insertions, 79 deletions

diff --git a/collector/stat_linux.go b/collector/stat_linux.go
index 00e1391..5e31108 100644
--- a/collector/stat_linux.go
+++ b/collector/stat_linux.go
@@ -16,16 +16,11 @@
 package collector
 
 import (
-        "bufio"
-        "os"
-        "strconv"
-        "strings"
+        "fmt"
 
-        "github.com/prometheus/client_golang/prometheus"
-)
+        "github.com/prometheus/procfs"
 
-const (
-        userHz = 100
+        "github.com/prometheus/client_golang/prometheus"
 )
 
 type statCollector struct {
@@ -83,80 +78,25 @@ func NewStatCollector() (Collector, error) {
         }, nil
 }
 
-// Expose kernel and system statistics.
+// Update implements Collector and exposes kernel and system statistics.
 func (c *statCollector) Update(ch chan<- prometheus.Metric) error {
-        file, err := os.Open(procFilePath("stat"))
+        fs, err := procfs.NewFS(*procPath)
+        if err != nil {
+                return fmt.Errorf("failed to open procfs: %v", err)
+        }
+        stats, err := fs.NewStat()
         if err != nil {
                 return err
         }
-        defer file.Close()
 
-        scanner := bufio.NewScanner(file)
-        for scanner.Scan() {
-                parts := strings.Fields(scanner.Text())
-                if len(parts) == 0 {
-                        continue
-                }
-                switch {
-                case strings.HasPrefix(parts[0], "cpu"):
-                        // Export only per-cpu stats, it can be aggregated up in prometheus.
-                        if parts[0] == "cpu" {
-                                break
-                        }
-                        // Only some of these may be present, depending on kernel version.
-                        cpuFields := []string{"user", "nice", "system", "idle", "iowait", "irq", "softirq", "steal", "guest", "guest_nice"}
-                        // OpenVZ guests lack the "guest" CPU field, which needs to be ignored.
-                        expectedFieldNum := len(cpuFields) + 1
-                        if expectedFieldNum > len(parts) {
-                                expectedFieldNum = len(parts)
-                        }
-                        for i, v := range parts[1:expectedFieldNum] {
-                                value, err := strconv.ParseFloat(v, 64)
-                                if err != nil {
-                                        return err
-                                }
-                                // Convert from ticks to seconds
-                                value /= userHz
-                                ch <- prometheus.MustNewConstMetric(c.cpu, prometheus.CounterValue, value, parts[0], cpuFields[i])
-                        }
-                case parts[0] == "intr":
-                        // Only expose the overall number, use the 'interrupts' collector for more detail.
-                        value, err := strconv.ParseFloat(parts[1], 64)
-                        if err != nil {
-                                return err
-                        }
-                        ch <- prometheus.MustNewConstMetric(c.intr, prometheus.CounterValue, value)
-                case parts[0] == "ctxt":
-                        value, err := strconv.ParseFloat(parts[1], 64)
-                        if err != nil {
-                                return err
-                        }
-                        ch <- prometheus.MustNewConstMetric(c.ctxt, prometheus.CounterValue, value)
-                case parts[0] == "processes":
-                        value, err := strconv.ParseFloat(parts[1], 64)
-                        if err != nil {
-                                return err
-                        }
-                        ch <- prometheus.MustNewConstMetric(c.forks, prometheus.CounterValue, value)
-                case parts[0] == "btime":
-                        value, err := strconv.ParseFloat(parts[1], 64)
-                        if err != nil {
-                                return err
-                        }
-                        ch <- prometheus.MustNewConstMetric(c.btime, prometheus.GaugeValue, value)
-                case parts[0] == "procs_running":
-                        value, err := strconv.ParseFloat(parts[1], 64)
-                        if err != nil {
-                                return err
-                        }
-                        ch <- prometheus.MustNewConstMetric(c.procsRunning, prometheus.GaugeValue, value)
-                case parts[0] == "procs_blocked":
-                        value, err := strconv.ParseFloat(parts[1], 64)
-                        if err != nil {
-                                return err
-                        }
-                        ch <- prometheus.MustNewConstMetric(c.procsBlocked, prometheus.GaugeValue, value)
-                }
-        }
-        return scanner.Err()
+        ch <- prometheus.MustNewConstMetric(c.intr, prometheus.CounterValue, float64(stats.IRQTotal))
+        ch <- prometheus.MustNewConstMetric(c.ctxt, prometheus.CounterValue, float64(stats.ContextSwitches))
+        ch <- prometheus.MustNewConstMetric(c.forks, prometheus.CounterValue, float64(stats.ProcessCreated))
+
+        ch <- prometheus.MustNewConstMetric(c.btime, prometheus.GaugeValue, float64(stats.BootTime))
+
+        ch <- prometheus.MustNewConstMetric(c.procsRunning, prometheus.GaugeValue, float64(stats.ProcessesRunning))
+        ch <- prometheus.MustNewConstMetric(c.procsBlocked, prometheus.GaugeValue, float64(stats.ProcessesBlocked))
+
+        return nil
 }