Add time exporter

This simple exporter exposes the systems unix time. It's useful to
compare it to the prometheus server time and other targets to detect
clock skew.

1 files changed, 47 insertions, 0 deletions

diff --git a/collector/time.go b/collector/time.go
new file mode 100644
index 0000000..172de88
--- /dev/null
+++ b/collector/time.go
@@ -0,0 +1,47 @@
+// +build !notime
+
+package collector
+
+import (
+        "time"
+
+        "github.com/golang/glog"
+        "github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+        systemTime = prometheus.NewCounter(prometheus.CounterOpts{
+                Namespace: Namespace,
+                Name:      "time",
+                Help:      "System time in seconds since epoch (1970).",
+        })
+)
+
+type timeCollector struct {
+        config Config
+}
+
+func init() {
+        Factories["time"] = NewTimeCollector
+}
+
+// Takes a config struct and prometheus registry and returns a new Collector exposing
+// the current system time in seconds since epoch.
+func NewTimeCollector(config Config) (Collector, error) {
+        c := timeCollector{
+                config: config,
+        }
+
+        if _, err := prometheus.RegisterOrGet(systemTime); err != nil {
+                return nil, err
+        }
+        return &c, nil
+}
+
+func (c *timeCollector) Update() (updates int, err error) {
+        updates++
+        now := time.Now()
+        glog.V(1).Infof("Set time: %f", now.Unix())
+        systemTime.Set(float64(now.Unix()))
+        return updates, err
+}