add ports flag to k8scan

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

k8scan/main_test.go

@@ -1,6 +1,9 @@
 package main
 
-import "testing"
+import (
+	"reflect"
+	"testing"
+)
 
 func TestARINResponse(t *testing.T) {
 	info, err := getIPInfo("104.40.92.107")
@@ -18,3 +21,41 @@ func TestARINResponse(t *testing.T) {
 		t.Fatalf("expected reference to be https://whois.arin.net/rest/org/MSFT, got %s", info.Net.Organization.Reference)
 	}
 }
+
+func TestParsePortRange(t *testing.T) {
+	testFuncs := []struct {
+		given    string
+		expected intSlice
+	}{
+		{
+			given:    "",
+			expected: intSlice{80, 443, 8001, 9001},
+		},
+		{
+			given:    "80,443,9090",
+			expected: intSlice{80, 443, 9090},
+		},
+		{
+			given:    "80-90",
+			expected: intSlice{80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90},
+		},
+		{
+			given:    "22-24,80,8080-8083",
+			expected: intSlice{22, 23, 24, 80, 8080, 8081, 8082, 8083},
+		},
+		{
+			given:    "80",
+			expected: intSlice{80},
+		},
+	}
+
+	for _, testFunc := range testFuncs {
+		i := intSlice{}
+		if err := i.Set(testFunc.given); err != nil {
+			t.Fatal(err)
+		}
+		if reflect.DeepEqual(testFunc.expected, i) {
+			t.Fatalf("expected: %#v\ngot: %#v", testFunc.expected, i)
+		}
+	}
+}