plugin/secondary: fix a bunch of things and tests (#1406)

Fix the error handling. Log when we have an error during any of the
transfer state. And if there isn't an error transfer the zones.

Also fix the tests in test/ so we, at least, check the initial transfer.

Update the docs to show more about how errors are handled.

Ref #1400

plugin/file/secondary.go

@@ -118,19 +118,6 @@ Restart:
 	retry := time.Second * time.Duration(z.Apex.SOA.Retry)
 	expire := time.Second * time.Duration(z.Apex.SOA.Expire)
 
-	if refresh < time.Hour {
-		refresh = time.Hour
-	}
-	if retry < time.Hour {
-		retry = time.Hour
-	}
-	if refresh > 24*time.Hour {
-		refresh = 24 * time.Hour
-	}
-	if retry > 12*time.Hour {
-		retry = 12 * time.Hour
-	}
-
 	refreshTicker := time.NewTicker(refresh)
 	retryTicker := time.NewTicker(retry)
 	expireTicker := time.NewTicker(expire)
@@ -151,7 +138,12 @@ Restart:
 			time.Sleep(jitter(2000)) // 2s randomize
 
 			ok, err := z.shouldTransfer()
-			if err != nil && ok {
+			if err != nil {
+				log.Printf("[WARNING] Failed retry check %s", err)
+				continue
+			}
+
+			if ok {
 				if err := z.TransferIn(); err != nil {
 					// transfer failed, leave retryActive true
 					break
@@ -169,8 +161,13 @@ Restart:
 			time.Sleep(jitter(5000)) // 5s randomize
 
 			ok, err := z.shouldTransfer()
-			retryActive = err != nil
-			if err != nil && ok {
+			if err != nil {
+				log.Printf("[WARNING] Failed refresh check %s", err)
+				retryActive = true
+				continue
+			}
+
+			if ok {
 				if err := z.TransferIn(); err != nil {
 					// transfer failed
 					retryActive = true

plugin/secondary/README.md

@@ -35,6 +35,10 @@ secondary [zones...] {
   normal authoritative serving you don't need *or* want to use this. **ADDRESS** can be an IP
   address, and IP:port or a string pointing to a file that is structured as /etc/resolv.conf.
 
+When a zone is due to be refreshed (Refresh timer fires) a random jitter of 5 seconds is
+applied, before fetching. In the case of retry this will be 2 seconds. If there are any errors
+during the transfer the transfer fails; this will be logged.
+
 ## Examples
 
 Transfer `example.org` from 10.0.1.1, and if that fails try 10.1.2.1.

test/secondary_net_test.go

-// +build net
-
-package test
-
-import (
-	"testing"
-
-	"github.com/miekg/dns"
-)
-
-func TestSecondaryZoneTransfer(t *testing.T) {
-	/*
-		Test will only work when there is a CoreDNS running on part 32054
-		with example.com and willing to transfer
-		coredns -conf Corefile -dns.port 32054
-		Corefile:
-			example.com {
-			    file example.com {
-				transfer to 127.0.0.1:32053
-			    }
-			}
-		example.com:
-			example.com.		3600	IN	SOA	sns.dns.icann.org. noc.dns.icann.org. 2017042730 7200 3600 1209600 3600
-
-			example.com.		65118	IN	NS	a.iana-servers.net.
-			example.com.		65118	IN	NS	b.iana-servers.net.
-			cname.example.com.       434334  IN      CNAME   a.miek.nl.
-	*/
-
-	corefile := `example.com:32053 {
-		secondary {
-			transfer from 127.0.0.1:32054
-		}
-	}
-	`
-
-	sec, err := CoreDNSServer(corefile)
-	if err != nil {
-		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
-	}
-
-	defer sec.Stop()
-
-	m := new(dns.Msg)
-	m.SetQuestion("cname.example.com.", dns.TypeCNAME)
-
-	r, err := dns.Exchange(m, "127.0.0.1:32053")
-	if err != nil {
-		t.Fatalf("Expected to receive reply, but didn't: %s", err)
-	}
-
-	if len(r.Answer) == 0 {
-		t.Fatalf("Expected answer section")
-	}
-
-	if r.Answer[0].(*dns.CNAME).Target != "a.miek.nl." {
-		t.Fatalf("Expected target of %s, got %s", "a.miek.nl.", r.Answer[0].(*dns.CNAME).Target)
-	}
-
-	m = new(dns.Msg)
-	m.SetQuestion("example.com.", dns.TypeSOA)
-	r, err = dns.Exchange(m, "127.0.0.1:32053")
-	if err != nil {
-		t.Fatalf("Expected to receive reply, but didn't: %s", err)
-	}
-	if len(r.Answer) == 0 {
-		t.Fatalf("Expected answer section")
-	}
-	if r.Answer[0].(*dns.SOA).Serial != 2017042730 {
-		t.Fatalf("Expected serial of %d, got %d", 2017042730, r.Answer[0].(*dns.SOA).Serial)
-	}
-}
-
-func TestSecondaryZoneTransferUpstream(t *testing.T) {
-	/*
-		Test will only work when there is a CoreDNS running on part 32054
-		with example.com and willing to transfer
-		coredns -conf Corefile -dns.port 32054
-		Corefile:
-			example.com {
-			    file example.com {
-				transfer to 127.0.0.1:32053
-			    }
-			}
-		example.com:
-			example.com.		3600	IN	SOA	sns.dns.icann.org. noc.dns.icann.org. 2017042730 7200 3600 1209600 3600
-
-			example.com.		65118	IN	NS	a.iana-servers.net.
-			example.com.		65118	IN	NS	b.iana-servers.net.
-			cname.example.com.       434334  IN      CNAME   a.miek.nl.
-	*/
-
-	corefile := `example.com:32053 {
-		secondary {
-			transfer from 127.0.0.1:32054
-			upstream 8.8.8.8
-		}
-	}
-	`
-
-	sec, err := CoreDNSServer(corefile)
-	if err != nil {
-		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
-	}
-
-	defer sec.Stop()
-
-	m := new(dns.Msg)
-	m.SetQuestion("cname.example.com.", dns.TypeA)
-
-	r, err := dns.Exchange(m, "127.0.0.1:32053")
-	if err != nil {
-		t.Fatalf("Expected to receive reply, but didn't: %s", err)
-	}
-
-	if len(r.Answer) != 2 {
-		t.Fatalf("Expected answer section, with 2 records, got %d", len(r.Answer))
-	}
-
-	if r.Answer[0].(*dns.CNAME).Target != "a.miek.nl." {
-		t.Fatalf("Expected target of %s, got %s", "a.miek.nl.", r.Answer[0].(*dns.CNAME).Target)
-	}
-	if r.Answer[1].Header().Name != "a.miek.nl." {
-		t.Fatalf("Expected name of %s, got %s", "a.miek.nl.", r.Answer[1].Header().Name)
-	}
-}

test/secondary_test.go

 package test
 
 import (
-	"io/ioutil"
-	"log"
 	"testing"
 
 	"github.com/coredns/coredns/plugin/proxy"
@@ -27,8 +25,6 @@ func TestEmptySecondaryZone(t *testing.T) {
 	}
 	defer i.Stop()
 
-	log.SetOutput(ioutil.Discard)
-
 	p := proxy.NewLookup([]string{udp})
 	state := request.Request{W: &test.ResponseWriter{}, Req: new(dns.Msg)}
 
@@ -40,3 +36,48 @@ func TestEmptySecondaryZone(t *testing.T) {
 		t.Fatalf("Expected reply to be a SERVFAIL, got %d", resp.Rcode)
 	}
 }
+
+func TestSecondaryZoneTransfer(t *testing.T) {
+	name, rm, err := test.TempFile(".", exampleOrg)
+	if err != nil {
+		t.Fatalf("failed to create zone: %s", err)
+	}
+	defer rm()
+
+	corefile := `example.org:0 {
+       file ` + name + ` {
+	       transfer to *
+       }
+}
+`
+
+	i, _, tcp, err := CoreDNSServerAndPorts(corefile)
+	if err != nil {
+		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
+	}
+	defer i.Stop()
+
+	corefile = `example.org:0 {
+		secondary {
+			transfer from ` + tcp + `
+		}
+}
+`
+	i1, udp, _, err := CoreDNSServerAndPorts(corefile)
+	if err != nil {
+		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
+	}
+	defer i1.Stop()
+
+	m := new(dns.Msg)
+	m.SetQuestion("example.org.", dns.TypeSOA)
+
+	r, err := dns.Exchange(m, udp)
+	if err != nil {
+		t.Fatalf("Expected to receive reply, but didn't: %s", err)
+	}
+
+	if len(r.Answer) == 0 {
+		t.Fatalf("Expected answer section")
+	}
+}