Merge pull request #2690 from zeroae/f-simple-rfc2782

RFC 2782 support with optional .service tag

command/agent/dns.go

@@ -304,12 +304,20 @@ func (d *DNSServer) dispatch(network string, req, resp *dns.Msg) {
 	// Split into the label parts
 	labels := dns.SplitDomainName(qName)
 
-	// The last label is either "node", "service", "query", or a datacenter name
+	// The last label is either "node", "service", "query", "_<protocol>", or a datacenter name
 PARSE:
 	n := len(labels)
 	if n == 0 {
 		goto INVALID
 	}
+
+	// If this is a SRV query the "service" label is optional, we add it back to use the
+	// existing code-path.
+	if req.Question[0].Qtype == dns.TypeSRV && strings.HasPrefix(labels[n-1], "_") {
+		labels = append(labels, "service")
+		n = n + 1
+	}
+
 	switch labels[n-1] {
 	case "service":
 		if n == 1 {

command/agent/dns_test.go

@@ -3488,47 +3488,57 @@ func TestDNS_ServiceLookup_SRV_RFC(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
-	m := new(dns.Msg)
+	questions := []string{
-	m.SetQuestion("_db._master.service.consul.", dns.TypeSRV)
+		"_db._master.service.dc1.consul.",
-
+		"_db._master.service.consul.",
-	c := new(dns.Client)
+		"_db._master.dc1.consul.",
-	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
+		"_db._master.consul.",
-	in, _, err := c.Exchange(m, addr.String())
-	if err != nil {
-		t.Fatalf("err: %v", err)
 	}
 
-	if len(in.Answer) != 1 {
+	for _, question := range questions {
-		t.Fatalf("Bad: %#v", in)
+		m := new(dns.Msg)
+		m.SetQuestion(question, dns.TypeSRV)
+
+		c := new(dns.Client)
+		addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
+		in, _, err := c.Exchange(m, addr.String())
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		if len(in.Answer) != 1 {
+			t.Fatalf("Bad: %#v", in)
+		}
+
+		srvRec, ok := in.Answer[0].(*dns.SRV)
+		if !ok {
+			t.Fatalf("Bad: %#v", in.Answer[0])
+		}
+		if srvRec.Port != 12345 {
+			t.Fatalf("Bad: %#v", srvRec)
+		}
+		if srvRec.Target != "foo.node.dc1.consul." {
+			t.Fatalf("Bad: %#v", srvRec)
+		}
+		if srvRec.Hdr.Ttl != 0 {
+			t.Fatalf("Bad: %#v", in.Answer[0])
+		}
+
+		aRec, ok := in.Extra[0].(*dns.A)
+		if !ok {
+			t.Fatalf("Bad: %#v", in.Extra[0])
+		}
+		if aRec.Hdr.Name != "foo.node.dc1.consul." {
+			t.Fatalf("Bad: %#v", in.Extra[0])
+		}
+		if aRec.A.String() != "127.0.0.1" {
+			t.Fatalf("Bad: %#v", in.Extra[0])
+		}
+		if aRec.Hdr.Ttl != 0 {
+			t.Fatalf("Bad: %#v", in.Extra[0])
+		}
 	}
 
-	srvRec, ok := in.Answer[0].(*dns.SRV)
-	if !ok {
-		t.Fatalf("Bad: %#v", in.Answer[0])
-	}
-	if srvRec.Port != 12345 {
-		t.Fatalf("Bad: %#v", srvRec)
-	}
-	if srvRec.Target != "foo.node.dc1.consul." {
-		t.Fatalf("Bad: %#v", srvRec)
-	}
-	if srvRec.Hdr.Ttl != 0 {
-		t.Fatalf("Bad: %#v", in.Answer[0])
-	}
-
-	aRec, ok := in.Extra[0].(*dns.A)
-	if !ok {
-		t.Fatalf("Bad: %#v", in.Extra[0])
-	}
-	if aRec.Hdr.Name != "foo.node.dc1.consul." {
-		t.Fatalf("Bad: %#v", in.Extra[0])
-	}
-	if aRec.A.String() != "127.0.0.1" {
-		t.Fatalf("Bad: %#v", in.Extra[0])
-	}
-	if aRec.Hdr.Ttl != 0 {
-		t.Fatalf("Bad: %#v", in.Extra[0])
-	}
 }
 
 func TestDNS_ServiceLookup_SRV_RFC_TCP_Default(t *testing.T) {
@@ -3555,47 +3565,57 @@ func TestDNS_ServiceLookup_SRV_RFC_TCP_Default(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
-	m := new(dns.Msg)
+	questions := []string{
-	m.SetQuestion("_db._tcp.service.consul.", dns.TypeSRV)
+		"_db._tcp.service.dc1.consul.",
-
+		"_db._tcp.service.consul.",
-	c := new(dns.Client)
+		"_db._tcp.dc1.consul.",
-	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
+		"_db._tcp.consul.",
-	in, _, err := c.Exchange(m, addr.String())
-	if err != nil {
-		t.Fatalf("err: %v", err)
 	}
 
-	if len(in.Answer) != 1 {
+	for _, question := range questions {
-		t.Fatalf("Bad: %#v", in)
+		m := new(dns.Msg)
+		m.SetQuestion(question, dns.TypeSRV)
+
+		c := new(dns.Client)
+		addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
+		in, _, err := c.Exchange(m, addr.String())
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		if len(in.Answer) != 1 {
+			t.Fatalf("Bad: %#v", in)
+		}
+
+		srvRec, ok := in.Answer[0].(*dns.SRV)
+		if !ok {
+			t.Fatalf("Bad: %#v", in.Answer[0])
+		}
+		if srvRec.Port != 12345 {
+			t.Fatalf("Bad: %#v", srvRec)
+		}
+		if srvRec.Target != "foo.node.dc1.consul." {
+			t.Fatalf("Bad: %#v", srvRec)
+		}
+		if srvRec.Hdr.Ttl != 0 {
+			t.Fatalf("Bad: %#v", in.Answer[0])
+		}
+
+		aRec, ok := in.Extra[0].(*dns.A)
+		if !ok {
+			t.Fatalf("Bad: %#v", in.Extra[0])
+		}
+		if aRec.Hdr.Name != "foo.node.dc1.consul." {
+			t.Fatalf("Bad: %#v", in.Extra[0])
+		}
+		if aRec.A.String() != "127.0.0.1" {
+			t.Fatalf("Bad: %#v", in.Extra[0])
+		}
+		if aRec.Hdr.Ttl != 0 {
+			t.Fatalf("Bad: %#v", in.Extra[0])
+		}
 	}
 
-	srvRec, ok := in.Answer[0].(*dns.SRV)
-	if !ok {
-		t.Fatalf("Bad: %#v", in.Answer[0])
-	}
-	if srvRec.Port != 12345 {
-		t.Fatalf("Bad: %#v", srvRec)
-	}
-	if srvRec.Target != "foo.node.dc1.consul." {
-		t.Fatalf("Bad: %#v", srvRec)
-	}
-	if srvRec.Hdr.Ttl != 0 {
-		t.Fatalf("Bad: %#v", in.Answer[0])
-	}
-
-	aRec, ok := in.Extra[0].(*dns.A)
-	if !ok {
-		t.Fatalf("Bad: %#v", in.Extra[0])
-	}
-	if aRec.Hdr.Name != "foo.node.dc1.consul." {
-		t.Fatalf("Bad: %#v", in.Extra[0])
-	}
-	if aRec.A.String() != "127.0.0.1" {
-		t.Fatalf("Bad: %#v", in.Extra[0])
-	}
-	if aRec.Hdr.Ttl != 0 {
-		t.Fatalf("Bad: %#v", in.Extra[0])
-	}
 }
 
 func TestDNS_ServiceLookup_FilterACL(t *testing.T) {

website/source/docs/agent/dns.html.markdown

@@ -138,7 +138,7 @@ foobar.node.dc1.consul.	0	IN	A	10.1.10.12
 
 The format for RFC 2782 SRV lookups is:
 
-    _<service>._<protocol>.service[.datacenter][.domain]
+    _<service>._<protocol>[.service][.datacenter][.domain]
 
 Per [RFC 2782](https://tools.ietf.org/html/rfc2782), SRV queries should use
 underscores, `_`, as a prefix to the `service` and `protocol` values in a query to