WIP: middleware/dnstap (#711)

middleware/dnstap add

middleware/dnstap/setup.go

@@ -0,0 +1,70 @@
+package dnstap
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/coredns/coredns/core/dnsserver"
+	"github.com/coredns/coredns/middleware"
+	"github.com/coredns/coredns/middleware/dnstap/out"
+
+	"github.com/mholt/caddy"
+	"github.com/mholt/caddy/caddyfile"
+)
+
+func init() {
+	caddy.RegisterPlugin("dnstap", caddy.Plugin{
+		ServerType: "dns",
+		Action:     wrapSetup,
+	})
+}
+
+func wrapSetup(c *caddy.Controller) error {
+	if err := setup(c); err != nil {
+		return middleware.Error("dnstap", err)
+	}
+	return nil
+}
+
+func parseConfig(c *caddyfile.Dispenser) (path string, full bool, err error) {
+	c.Next() // directive name
+
+	if !c.Args(&path) {
+		err = c.ArgErr()
+		return
+	}
+
+	full = c.NextArg() && c.Val() == "full"
+
+	return
+}
+
+func setup(c *caddy.Controller) error {
+	path, full, err := parseConfig(&c.Dispenser)
+	if err != nil {
+		return err
+	}
+
+	dnstap := Dnstap{Pack: full}
+
+	o, err := out.NewSocket(path)
+	if err != nil {
+		log.Printf("[WARN] Can't connect to %s at the moment", path)
+	}
+	dnstap.Out = o
+
+	c.OnShutdown(func() error {
+		if err := o.Close(); err != nil {
+			return fmt.Errorf("output: %s", err)
+		}
+		return nil
+	})
+
+	dnsserver.GetConfig(c).AddMiddleware(
+		func(next middleware.Handler) middleware.Handler {
+			dnstap.Next = next
+			return dnstap
+		})
+
+	return nil
+}