Merge pull request #224 from hashicorp/f-case-insensitivity

DNS case-insensitivity

CHANGELOG.md

@@ -1,3 +1,9 @@
+## 0.3.2 (Unreleased)
+
+IMPROVEMENTS:
+
+  * DNS case-insensitivity [GH-189]
+
 ## 0.3.1 (July 21, 2014)
 
 FEATURES:

command/agent/dns.go

@@ -248,7 +248,7 @@ func (d *DNSServer) dispatch(network string, req, resp *dns.Msg) {
 	datacenter := d.agent.config.Datacenter
 
 	// Get the QName without the domain suffix
-	qName := dns.Fqdn(req.Question[0].Name)
+	qName := strings.ToLower(dns.Fqdn(req.Question[0].Name))
 	qName = strings.TrimSuffix(qName, d.domain)
 
 	// Split into the label parts

command/agent/dns_test.go

@@ -136,6 +136,40 @@ func TestDNS_NodeLookup(t *testing.T) {
 	}
 }
 
+func TestDNS_CaseInsensitiveNodeLookup(t *testing.T) {
+	dir, srv := makeDNSServer(t)
+	defer os.RemoveAll(dir)
+	defer srv.agent.Shutdown()
+
+	testutil.WaitForLeader(t, srv.agent.RPC, "dc1")
+
+	// Register node
+	args := &structs.RegisterRequest{
+		Datacenter: "dc1",
+		Node:       "Foo",
+		Address:    "127.0.0.1",
+	}
+
+	var out struct{}
+	if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	m := new(dns.Msg)
+	m.SetQuestion("fOO.node.dc1.consul.", dns.TypeANY)
+
+	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("empty lookup: %#v", in)
+	}
+}
+
 func TestDNS_NodeLookup_PeriodName(t *testing.T) {
 	dir, srv := makeDNSServer(t)
 	defer os.RemoveAll(dir)
@@ -336,6 +370,45 @@ func TestDNS_ServiceLookup(t *testing.T) {
 	}
 }
 
+func TestDNS_CaseInsensitiveServiceLookup(t *testing.T) {
+	dir, srv := makeDNSServer(t)
+	defer os.RemoveAll(dir)
+	defer srv.agent.Shutdown()
+
+	testutil.WaitForLeader(t, srv.agent.RPC, "dc1")
+
+	// Register node
+	args := &structs.RegisterRequest{
+		Datacenter: "dc1",
+		Node:       "foo",
+		Address:    "127.0.0.1",
+		Service: &structs.NodeService{
+			Service: "Db",
+			Tags:    []string{"Master"},
+			Port:    12345,
+		},
+	}
+
+	var out struct{}
+	if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	m := new(dns.Msg)
+	m.SetQuestion("mASTER.dB.service.consul.", 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("empty lookup: %#v", in)
+	}
+}
+
 func TestDNS_ServiceLookup_TagPeriod(t *testing.T) {
 	dir, srv := makeDNSServer(t)
 	defer os.RemoveAll(dir)

consul/catalog_endpoint_test.go

@@ -220,13 +220,13 @@ func TestCatalogListNodes(t *testing.T) {
 	})
 
 	// Server node is auto added from Serf
-	if out.Nodes[0].Node != s1.config.NodeName {
+	if out.Nodes[1].Node != s1.config.NodeName {
 		t.Fatalf("bad: %v", out)
 	}
-	if out.Nodes[1].Node != "foo" {
+	if out.Nodes[0].Node != "foo" {
 		t.Fatalf("bad: %v", out)
 	}
-	if out.Nodes[1].Address != "127.0.0.1" {
+	if out.Nodes[0].Address != "127.0.0.1" {
 		t.Fatalf("bad: %v", out)
 	}
 }

consul/mdb_table.go

@@ -45,12 +45,13 @@ type MDBTables []*MDBTable
 // An Index is named, and uses a series of column values to
 // map to the row-id containing the table
 type MDBIndex struct {
-	AllowBlank bool      // Can fields be blank
-	Unique     bool      // Controls if values are unique
-	Fields     []string  // Fields are used to build the index
-	IdxFunc    IndexFunc // Can be used to provide custom indexing
-	Virtual    bool      // Virtual index does not exist, but can be used for queries
-	RealIndex  string    // Virtual indexes use a RealIndex for iteration
+	AllowBlank      bool      // Can fields be blank
+	Unique          bool      // Controls if values are unique
+	Fields          []string  // Fields are used to build the index
+	IdxFunc         IndexFunc // Can be used to provide custom indexing
+	Virtual         bool      // Virtual index does not exist, but can be used for queries
+	RealIndex       string    // Virtual indexes use a RealIndex for iteration
+	CaseInsensitive bool      // Controls if values are case-insensitive
 
 	table     *MDBTable
 	name      string
@@ -426,6 +427,10 @@ func (t *MDBTable) getIndex(index string, parts []string) (*MDBIndex, []byte, er
 		return nil, nil, tooManyFields
 	}
 
+	if idx.CaseInsensitive {
+		parts = ToLowerList(parts)
+	}
+
 	// Construct the key
 	key := idx.keyFromParts(parts...)
 	return idx, key, nil
@@ -613,6 +618,9 @@ func (i *MDBIndex) keyFromObject(obj interface{}) ([]byte, error) {
 		if !i.AllowBlank && val == "" {
 			return nil, fmt.Errorf("Field '%s' must be set: %#v", field, obj)
 		}
+		if i.CaseInsensitive {
+			val = strings.ToLower(val)
+		}
 		parts = append(parts, val)
 	}
 	key := i.keyFromParts(parts...)

consul/state_store.go

@@ -179,6 +179,7 @@ func (s *StateStore) initialize() error {
 			"id": &MDBIndex{
 				Unique: true,
 				Fields: []string{"Node"},
+				CaseInsensitive: true,
 			},
 		},
 		Decoder: func(buf []byte) interface{} {
@@ -200,6 +201,7 @@ func (s *StateStore) initialize() error {
 			"service": &MDBIndex{
 				AllowBlank: true,
 				Fields:     []string{"ServiceName"},
+				CaseInsensitive: true,
 			},
 		},
 		Decoder: func(buf []byte) interface{} {
@@ -640,7 +642,7 @@ func serviceTagFilter(l []interface{}, tag string) []interface{} {
 	n := len(l)
 	for i := 0; i < n; i++ {
 		srv := l[i].(*structs.ServiceNode)
-		if !strContains(srv.ServiceTags, tag) {
+		if !strContains(ToLowerList(srv.ServiceTags), strings.ToLower(tag)) {
 			l[i], l[n-1] = l[n-1], nil
 			i--
 			n--

consul/util.go

@@ -9,6 +9,7 @@ import (
 	"path/filepath"
 	"runtime"
 	"strconv"
+	"strings"
 
 	"github.com/hashicorp/serf/serf"
 )
@@ -68,6 +69,14 @@ func strContains(l []string, s string) bool {
 	return false
 }
 
+func ToLowerList(l []string) []string {
+	var out []string
+	for _, value := range l {
+		out = append(out, strings.ToLower(value))
+	}
+	return out
+}
+
 // ensurePath is used to make sure a path exists
 func ensurePath(path string, dir bool) error {
 	if !dir {

consul/util_test.go

@@ -18,6 +18,15 @@ func TestStrContains(t *testing.T) {
 	}
 }
 
+func TestToLowerList(t *testing.T) {
+	l := []string{"ABC", "Abc", "abc"}
+	for _, value := range ToLowerList(l) {
+		if value != "abc" {
+			t.Fatalf("failed lowercasing")
+		}
+	}
+}
+
 func TestIsPrivateIP(t *testing.T) {
 	if !isPrivateIP("192.168.1.1") {
 		t.Fatalf("bad")

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

@@ -20,7 +20,8 @@ with no failing health checks. It's that simple!
 There are a number of [configuration options](/docs/agent/options.html) that
 are important for the DNS interface. They are `client_addr`, `ports.dns`, `recursor`,
 `domain`, and `dns_config`. By default Consul will listen on 127.0.0.1:8600 for DNS queries
-in the "consul." domain, without support for DNS recursion.
+in the "consul." domain, without support for DNS recursion. All queries are case-insensitive, a
+name lookup for `PostgreSQL.node.dc1.consul` will find all nodes named `postgresql`, no matter of case.
 
 There are a few ways to use the DNS interface. One option is to use a custom
 DNS resolver library and point it at Consul. Another option is to set Consul