refactored for easier mainenance, add Alloc and Metrics classes

cmd/metrics.go

@@ -0,0 +1,75 @@
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// custom labels
+type Label struct {
+	Name, Value string
+}
+
+// simple prometheus wrapper
+type Metrics struct {
+	run      *prometheus.GaugeVec
+	latency  *prometheus.GaugeVec
+	registry *prometheus.Registry
+	values   []string
+}
+
+func NewMetrics(conf *Config) *Metrics {
+	labels := []string{"file", "maxwait"}
+	LabelLen := 2
+
+	for _, label := range conf.Labels {
+		labels = append(labels, label.Name)
+	}
+
+	metrics := &Metrics{
+		run: prometheus.NewGaugeVec(
+			prometheus.GaugeOpts{
+				Name: "io_exporter_io_operation",
+				Help: "whether io is working on the pvc, 1=ok, 0=fail",
+			},
+			labels,
+		),
+		latency: prometheus.NewGaugeVec(
+			prometheus.GaugeOpts{
+				Name: "io_exporter_io_latency",
+				Help: "how long does the operation take in seconds",
+			},
+			labels,
+		),
+
+		// use fixed size slice to avoid repeated allocs
+		values: make([]string, LabelLen+len(conf.Labels)),
+
+		registry: prometheus.NewRegistry(),
+	}
+
+	metrics.registry.MustRegister(metrics.run, metrics.latency)
+
+	// static labels
+	metrics.values[0] = conf.File
+	metrics.values[1] = fmt.Sprintf("%d", conf.Timeout)
+
+	// custom labels via -l label=value
+	for idx, label := range conf.Labels {
+		metrics.values[idx+LabelLen] = label.Value
+	}
+
+	return metrics
+}
+
+func (metrics *Metrics) Set(result bool, elapsed float64) {
+	var res float64
+
+	if result {
+		res = 1
+	}
+
+	metrics.run.WithLabelValues(metrics.values...).Set(res)
+	metrics.latency.WithLabelValues(metrics.values...).Set(elapsed)
+}