Add collector for /proc/net/tcp

collector/tcpstat_test.go

@@ -0,0 +1,27 @@
+package collector
+
+import (
+	"os"
+	"testing"
+)
+
+func TestTCPStat(t *testing.T) {
+	file, err := os.Open("fixtures/tcpstat")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer file.Close()
+
+	tcpStats, err := parseTCPStats(file)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if want, got := 1, int(tcpStats[TCP_ESTABLISHED]); want != got {
+		t.Errorf("want tcpstat number of established state %d, got %d", want, got)
+	}
+
+	if want, got := 1, int(tcpStats[TCP_LISTEN]); want != got {
+		t.Errorf("want tcpstat number of listen state %d, got %d", want, got)
+	}
+}