add configurable punching delay because of race-condition-y conntracks (#210)

* add configurable punching delay because of race-condition-y conntracks

* add changelog

* fix tests

* only do one punch per query

* Coalesce punchy config

* It is not is not set

* Add tests

Co-authored-by: Nate Brown <nbrown.us@gmail.com>

punchy_test.go

@@ -0,0 +1,43 @@
+package nebula
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+	"time"
+)
+
+func TestNewPunchyFromConfig(t *testing.T) {
+	c := NewConfig()
+
+	// Test defaults
+	p := NewPunchyFromConfig(c)
+	assert.Equal(t, false, p.Punch)
+	assert.Equal(t, false, p.Respond)
+	assert.Equal(t, time.Second, p.Delay)
+
+	// punchy deprecation
+	c.Settings["punchy"] = true
+	p = NewPunchyFromConfig(c)
+	assert.Equal(t, true, p.Punch)
+
+	// punchy.punch
+	c.Settings["punchy"] = map[interface{}]interface{}{"punch": true}
+	p = NewPunchyFromConfig(c)
+	assert.Equal(t, true, p.Punch)
+
+	// punch_back deprecation
+	c.Settings["punch_back"] = true
+	p = NewPunchyFromConfig(c)
+	assert.Equal(t, true, p.Respond)
+
+	// punchy.respond
+	c.Settings["punchy"] = map[interface{}]interface{}{"respond": true}
+	c.Settings["punch_back"] = false
+	p = NewPunchyFromConfig(c)
+	assert.Equal(t, true, p.Respond)
+
+	// punchy.delay
+	c.Settings["punchy"] = map[interface{}]interface{}{"delay": "1m"}
+	p = NewPunchyFromConfig(c)
+	assert.Equal(t, time.Minute, p.Delay)
+}