New plugin: loop (#1989)

* New plugin: loop

Add a plugin that detects loops. It does this by sending an unique query
to our selves. If we see the query more than twice we stop the process.
If there isn't a loop, the plugin disables it self and becomes a noop
plugin.

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

1 files changed, 19 insertions, 0 deletions

diff --git a/plugin/loop/setup_test.go b/plugin/loop/setup_test.go
new file mode 100644
index 000000000..2a3c6846f
--- /dev/null
+++ b/plugin/loop/setup_test.go
@@ -0,0 +1,19 @@
+package loop
+
+import (
+	"testing"
+
+	"github.com/mholt/caddy"
+)
+
+func TestSetup(t *testing.T) {
+	c := caddy.NewTestController("dns", `loop`)
+	if err := setup(c); err != nil {
+		t.Fatalf("Expected no errors, but got: %v", err)
+	}
+
+	c = caddy.NewTestController("dns", `loop argument`)
+	if err := setup(c); err == nil {
+		t.Fatal("Expected errors, but got none")
+	}
+}