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open-consul
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Fix some edge cases and add some tests.

This commit is contained in:
Matt Keeler 2018-07-02 16:58:52 -04:00
parent e3859b4f04
commit 22cc44877d
2 changed files with 196 additions and 1 deletions
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13
agent/dns.go
View File

@ -1144,6 +1144,7 @@ func (d *DNSServer) serviceNodeRecords(dc string, nodes structs.CheckServiceNode
handled := make(map[string]struct{})
edns := req.IsEdns0() != nil
haveCNAME := false
allowCNAME := true
count := 0
for _, node := range nodes {
@ -1173,10 +1174,20 @@ func (d *DNSServer) serviceNodeRecords(dc string, nodes structs.CheckServiceNode
// only allow at most 1 CNAME record
switch records[0].(type) {
case *dns.CNAME:
if haveCNAME {
if haveCNAME || !allowCNAME {
continue
} else {
haveCNAME = true
allowCNAME = false
}
default:
if haveCNAME {
// clear the slice - this removes the 1 and only CNAME
// in favor of returning records without a CNAME
resp.Answer = nil
} else {
// we don't exactly have one but we don't want one now either
allowCNAME = false
}
}

184
agent/dns_test.go
View File

@ -946,6 +946,190 @@ func TestDNS_ServiceReverseLookupNodeAddress(t *testing.T) {
}
}
func TestDNS_ServiceLookupNoMultiCNAME(t *testing.T) {
t.Parallel()
a := NewTestAgent(t.Name(), "")
defer a.Shutdown()
// Register a node with a service.
{
args := &structs.RegisterRequest{
Datacenter: "dc1",
Node: "foo",
Address: "198.18.0.1",
Service: &structs.NodeService{
Service: "db",
Port: 12345,
Address: "foo.node.consul",
},
}
var out struct{}
require.NoError(t, a.RPC("Catalog.Register", args, &out))
}
// Register a second node node with the same service.
{
args := &structs.RegisterRequest{
Datacenter: "dc1",
Node: "bar",
Address: "198.18.0.2",
Service: &structs.NodeService{
Service: "db",
Port: 12345,
Address: "bar.node.consul",
},
}
var out struct{}
if err := a.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, a.DNSAddr())
require.NoError(t, err)
// expect a CNAME and an A RR
require.Len(t, in.Answer, 2)
require.IsType(t, &dns.CNAME{}, in.Answer[0])
require.IsType(t, &dns.A{}, in.Answer[1])
}
func TestDNS_ServiceLookupPreferNoCNAME(t *testing.T) {
t.Parallel()
a := NewTestAgent(t.Name(), "")
defer a.Shutdown()
// Register a node with a service.
{
args := &structs.RegisterRequest{
Datacenter: "dc1",
Node: "foo",
Address: "198.18.0.1",
Service: &structs.NodeService{
Service: "db",
Port: 12345,
Address: "198.18.0.1",
},
}
var out struct{}
require.NoError(t, a.RPC("Catalog.Register", args, &out))
}
// Register a second node node with the same service.
{
args := &structs.RegisterRequest{
Datacenter: "dc1",
Node: "bar",
Address: "198.18.0.2",
Service: &structs.NodeService{
Service: "db",
Port: 12345,
Address: "bar.node.consul",
},
}
var out struct{}
if err := a.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, a.DNSAddr())
require.NoError(t, err)
// expect a CNAME and an A RR
require.Len(t, in.Answer, 1)
aRec, ok := in.Answer[0].(*dns.A)
require.Truef(t, ok, "Not an A RR")
require.Equal(t, "db.service.consul.", aRec.Hdr.Name)
require.Equal(t, "198.18.0.1", aRec.A.String())
}
func TestDNS_ServiceLookupMultiAddrNoCNAME(t *testing.T) {
t.Parallel()
a := NewTestAgent(t.Name(), "")
defer a.Shutdown()
// Register a node with a service.
{
args := &structs.RegisterRequest{
Datacenter: "dc1",
Node: "foo",
Address: "198.18.0.1",
Service: &structs.NodeService{
Service: "db",
Port: 12345,
Address: "198.18.0.1",
},
}
var out struct{}
require.NoError(t, a.RPC("Catalog.Register", args, &out))
}
// Register a second node node with the same service.
{
args := &structs.RegisterRequest{
Datacenter: "dc1",
Node: "bar",
Address: "198.18.0.2",
Service: &structs.NodeService{
Service: "db",
Port: 12345,
Address: "bar.node.consul",
},
}
var out struct{}
if err := a.RPC("Catalog.Register", args, &out); err != nil {
t.Fatalf("err: %v", err)
}
}
// Register a second node node with the same service.
{
args := &structs.RegisterRequest{
Datacenter: "dc1",
Node: "baz",
Address: "198.18.0.3",
Service: &structs.NodeService{
Service: "db",
Port: 12345,
Address: "198.18.0.3",
},
}
var out struct{}
if err := a.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, a.DNSAddr())
require.NoError(t, err)
// expect a CNAME and an A RR
require.Len(t, in.Answer, 2)
require.IsType(t, &dns.A{}, in.Answer[0])
require.IsType(t, &dns.A{}, in.Answer[1])
}
func TestDNS_ServiceLookup(t *testing.T) {
t.Parallel()
a := NewTestAgent(t.Name(), "")