Added CoreDNS plugin setup and replaced forward

upstream/upstream.go

@@ -5,8 +5,6 @@ import (
 	"github.com/miekg/dns"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
-	"log"
-	"runtime"
 	"time"
 )
 
@@ -14,8 +12,6 @@ const (
 	defaultTimeout = 5 * time.Second
 )
 
-// TODO: Add a helper method for health-checking an upstream (see health.go in coredns)
-
 // Upstream is a simplified interface for proxy destination
 type Upstream interface {
 	Exchange(ctx context.Context, query *dns.Msg) (*dns.Msg, error)
@@ -30,10 +26,10 @@ type UpstreamPlugin struct {
 
 // Initialize the upstream plugin
 func New() *UpstreamPlugin {
-	p := &UpstreamPlugin{}
+	p := &UpstreamPlugin{
+		Upstreams: []Upstream{},
+	}
 
-	// Make sure all resources are cleaned up
-	runtime.SetFinalizer(p, (*UpstreamPlugin).finalizer)
 	return p
 }
 
@@ -56,15 +52,3 @@ func (p *UpstreamPlugin) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *
 
 // Name implements interface for CoreDNS plugin
 func (p *UpstreamPlugin) Name() string { return "upstream" }
-
-func (p *UpstreamPlugin) finalizer() {
-
-	for i := range p.Upstreams {
-
-		u := p.Upstreams[i]
-		err := u.Close()
-		if err != nil {
-			log.Printf("Error while closing the upstream: %s", err)
-		}
-	}
-}