Add MegaCLI collector

This collector exports the following metrics:

- raid_drive_temperature: drive temperature
- raid_drive_count: drive error and event counters
- raid_adapter_disk_presence: disk presence per adapter

collector/megacli_test.go

@@ -0,0 +1,54 @@
+// +build megacli
+
+package collector
+
+import (
+	"os"
+	"testing"
+)
+
+const (
+	testMegaCliAdapter = "fixtures/megacli_adapter.txt"
+	testMegaCliDisks   = "fixtures/megacli_disks.txt"
+
+	physicalDevicesExpected = "5"
+	virtualDevicesDegraded  = "0"
+)
+
+func TestMegaCliAdapter(t *testing.T) {
+	data, err := os.Open(testMegaCliAdapter)
+	if err != nil {
+		t.Fatal(err)
+	}
+	stats, err := parseMegaCliAdapter(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if stats["Device Present"]["Physical Devices"] != physicalDevicesExpected {
+		t.Fatalf("Unexpected device count: %d != %d", stats["Device Present"]["Physical Devices"], physicalDevicesExpected)
+	}
+
+	if stats["Device Present"]["Degraded"] != virtualDevicesDegraded {
+		t.Fatal()
+	}
+}
+
+func TestMegaCliDisks(t *testing.T) {
+	data, err := os.Open(testMegaCliDisks)
+	if err != nil {
+		t.Fatal(err)
+	}
+	stats, err := parseMegaCliDisks(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if stats[32][0]["Drive Temperature"] != "37C (98.60 F)" {
+		t.Fatalf("Unexpected drive temperature: %s", stats[32][0]["Drive Temperature"])
+	}
+
+	if stats[32][3]["Predictive Failure Count"] != "23" {
+		t.Fatal()
+	}
+}