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open-consul
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Testing DNS correctly deduplicates records

This commit is contained in:
Armon Dadgar 2014-01-06 14:56:41 -08:00
parent ed1a200efe
commit 1f3fedf8b8
2 changed files with 128 additions and 0 deletions
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25
command/agent/dns.go
View File

@ -327,7 +327,15 @@ func (d *DNSServer) serviceLookup(datacenter, service, tag string, req, resp *dn
// serviceARecords is used to add the A records for a service lookup
func (d *DNSServer) serviceARecords(nodes structs.ServiceNodes, req, resp *dns.Msg) {
handled := make(map[string]struct{})
for _, node := range nodes {
// Avoid duplicate entries, possible if a node has
// the same service on multiple ports, etc.
if _, ok := handled[node.Address]; ok {
continue
}
handled[node.Address] = struct{}{}
ip := net.ParseIP(node.Address)
if ip == nil {
d.logger.Printf("[ERR] dns: failed to parse IP %v for %v", node.Address, node.Node)
@ -348,7 +356,17 @@ func (d *DNSServer) serviceARecords(nodes structs.ServiceNodes, req, resp *dns.M
// serviceARecords is used to add the SRV records for a service lookup
func (d *DNSServer) serviceSRVRecords(dc string, nodes structs.ServiceNodes, req, resp *dns.Msg) {
handled := make(map[string]struct{})
for _, node := range nodes {
// Avoid duplicate entries, possible if a node has
// the same service the same port, etc.
tuple := fmt.Sprintf("%s:%d", node.Node, node.ServicePort)
if _, ok := handled[tuple]; ok {
continue
}
handled[tuple] = struct{}{}
// Add the SRV record
srvRec := &dns.SRV{
Hdr: dns.RR_Header{
Name: req.Question[0].Name,
@ -363,6 +381,13 @@ func (d *DNSServer) serviceSRVRecords(dc string, nodes structs.ServiceNodes, req
}
resp.Answer = append(resp.Answer, srvRec)
// Avoid duplicate A records, possible if a node has
// the same service on multiple ports, etc.
if _, ok := handled[node.Address]; ok {
continue
}
handled[node.Address] = struct{}{}
ip := net.ParseIP(node.Address)
if ip == nil {
d.logger.Printf("[ERR] dns: failed to parse IP %v for %v", node.Address, node.Node)

103
command/agent/dns_test.go
View File

@ -175,6 +175,109 @@ func TestDNS_ServiceLookup(t *testing.T) {
}
}
func TestDNS_ServiceLookup_Dedup(t *testing.T) {
dir, srv := makeDNSServer(t)
defer os.RemoveAll(dir)
defer srv.agent.Shutdown()
// Wait for leader
time.Sleep(100 * time.Millisecond)
// Register node
args := &structs.RegisterRequest{
Datacenter: "dc1",
Node: "foo",
Address: "127.0.0.1",
ServiceName: "db",
ServiceTag: "master",
ServicePort: 12345,
}
var out struct{}
if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
t.Fatalf("err: %v", err)
}
args = &structs.RegisterRequest{
Datacenter: "dc1",
Node: "foo",
Address: "127.0.0.1",
ServiceID: "db2",
ServiceName: "db",
ServiceTag: "slave",
ServicePort: 12345,
}
if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
t.Fatalf("err: %v", err)
}
args = &structs.RegisterRequest{
Datacenter: "dc1",
Node: "foo",
Address: "127.0.0.1",
ServiceID: "db3",
ServiceName: "db",
ServiceTag: "slave",
ServicePort: 12346,
}
if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
t.Fatalf("err: %v", err)
}
m := new(dns.Msg)
m.SetQuestion("db.service.consul.", dns.TypeANY)
c := new(dns.Client)
in, _, err := c.Exchange(m, srv.agent.config.DNSAddr)
if err != nil {
t.Fatalf("err: %v", err)
}
if len(in.Answer) != 3 {
t.Fatalf("Bad: %#v", in)
}
aRec, ok := in.Answer[0].(*dns.A)
if !ok {
t.Fatalf("Bad: %#v", in.Answer[0])
}
if aRec.A.String() != "127.0.0.1" {
t.Fatalf("Bad: %#v", in.Answer[0])
}
srvRec, ok := in.Answer[1].(*dns.SRV)
if !ok {
t.Fatalf("Bad: %#v", in.Answer[1])
}
if srvRec.Port != 12345 {
t.Fatalf("Bad: %#v", srvRec)
}
if srvRec.Target != "foo.node.dc1.consul." {
t.Fatalf("Bad: %#v", srvRec)
}
srvRec, ok = in.Answer[2].(*dns.SRV)
if !ok {
t.Fatalf("Bad: %#v", in.Answer[1])
}
if srvRec.Port != 12346 {
t.Fatalf("Bad: %#v", srvRec)
}
if srvRec.Target != "foo.node.dc1.consul." {
t.Fatalf("Bad: %#v", srvRec)
}
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])
}
}
func TestDNS_Recurse(t *testing.T) {
dir, srv := makeDNSServer(t)
defer os.RemoveAll(dir)