Add traffic plugin

This allows for advanced loadbalancing and maybe geoIP loadbalancing.

Signed-off-by: Miek Gieben <miek@miek.nl>

plugin/traffic/setup_test.go

@@ -0,0 +1,34 @@
+package traffic
+
+import (
+	"testing"
+
+	"github.com/caddyserver/caddy"
+)
+
+func TestSetup(t *testing.T) {
+	tests := []struct {
+		input     string
+		shouldErr bool
+	}{
+		// positive
+		{`traffic`, false},
+		// negative
+		{`traffic fleeb`, true},
+	}
+
+	for i, test := range tests {
+		c := caddy.NewTestController("dns", test.input)
+		err := parse(c)
+
+		if test.shouldErr && err == nil {
+			t.Errorf("Test %d: Expected error but found %s for input %s", i, err, test.input)
+		}
+
+		if err != nil {
+			if !test.shouldErr {
+				t.Errorf("Test %d: Expected no error but found one for input %s. Error was: %v", i, test.input, err)
+			}
+		}
+	}
+}