From 02d6acd8fc6783511e52a3b3c5045cd1ba125ee9 Mon Sep 17 00:00:00 2001
From: freddygv <gh@freddygv.xyz>
Date: Thu, 3 Sep 2020 08:55:57 -0600
Subject: [PATCH] Ensure resolver node with LB isn't considered default

---
 agent/consul/discoverychain/compile_test.go | 65 ++++++++++++++++++++-
 agent/structs/discovery_chain.go            |  3 +
 api/discovery_chain.go                      |  3 +
 3 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/agent/consul/discoverychain/compile_test.go b/agent/consul/discoverychain/compile_test.go
index 7e4c78dc8..af6597175 100644
--- a/agent/consul/discoverychain/compile_test.go
+++ b/agent/consul/discoverychain/compile_test.go
@@ -51,7 +51,8 @@ func TestCompile(t *testing.T) {
 		"default resolver with external sni":               testcase_DefaultResolver_ExternalSNI(),
 		"resolver with no entries and inferring defaults":  testcase_DefaultResolver(),
 		"default resolver with proxy defaults":             testcase_DefaultResolver_WithProxyDefaults(),
-		"loadbalancer config":                              testcase_LBConfig(),
+		"loadbalancer splitter and resolver":               testcase_LBSplitterAndResolver(),
+		"loadbalancer resolver":                            testcase_LBResolver(),
 		"service redirect to service with default resolver is not a default chain": testcase_RedirectToDefaultResolverIsNotDefaultChain(),
 
 		"all the bells and whistles": testcase_AllBellsAndWhistles(),
@@ -2259,7 +2260,7 @@ func testcase_CircularSplit() compileTestCase {
 	}
 }
 
-func testcase_LBConfig() compileTestCase {
+func testcase_LBSplitterAndResolver() compileTestCase {
 	entries := newEntries()
 	setServiceProtocol(entries, "foo", "http")
 	setServiceProtocol(entries, "bar", "http")
@@ -2442,6 +2443,66 @@ func testcase_LBConfig() compileTestCase {
 	return compileTestCase{entries: entries, expect: expect}
 }
 
+// ensure chain with LB cfg in resolver isn't a default chain (!IsDefault)
+func testcase_LBResolver() compileTestCase {
+	entries := newEntries()
+	setServiceProtocol(entries, "main", "http")
+
+	entries.AddResolvers(
+		&structs.ServiceResolverConfigEntry{
+			Kind: "service-resolver",
+			Name: "main",
+			LoadBalancer: &structs.LoadBalancer{
+				EnvoyConfig: &structs.EnvoyLBConfig{
+					Policy: "ring_hash",
+					RingHashConfig: &structs.RingHashConfig{
+						MaximumRingSize: 101,
+					},
+					HashPolicies: []structs.HashPolicy{
+						{
+							SourceIP: true,
+						},
+					},
+				},
+			},
+		},
+	)
+
+	expect := &structs.CompiledDiscoveryChain{
+		Protocol:  "http",
+		StartNode: "resolver:main.default.dc1",
+		Nodes: map[string]*structs.DiscoveryGraphNode{
+			"resolver:main.default.dc1": {
+				Type: structs.DiscoveryGraphNodeTypeResolver,
+				Name: "main.default.dc1",
+				Resolver: &structs.DiscoveryResolver{
+					Default:        true,
+					ConnectTimeout: 5 * time.Second,
+					Target:         "main.default.dc1",
+				},
+				LoadBalancer: &structs.LoadBalancer{
+					EnvoyConfig: &structs.EnvoyLBConfig{
+						Policy: "ring_hash",
+						RingHashConfig: &structs.RingHashConfig{
+							MaximumRingSize: 101,
+						},
+						HashPolicies: []structs.HashPolicy{
+							{
+								SourceIP: true,
+							},
+						},
+					},
+				},
+			},
+		},
+		Targets: map[string]*structs.DiscoveryTarget{
+			"main.default.dc1": newTarget("main", "", "default", "dc1", nil),
+		},
+	}
+
+	return compileTestCase{entries: entries, expect: expect}
+}
+
 func newSimpleRoute(name string, muts ...func(*structs.ServiceRoute)) structs.ServiceRoute {
 	r := structs.ServiceRoute{
 		Match: &structs.ServiceRouteMatch{
diff --git a/agent/structs/discovery_chain.go b/agent/structs/discovery_chain.go
index 77eb03937..5e2ff9498 100644
--- a/agent/structs/discovery_chain.go
+++ b/agent/structs/discovery_chain.go
@@ -82,6 +82,9 @@ func (c *CompiledDiscoveryChain) IsDefault() bool {
 	if !node.Resolver.Default {
 		return false
 	}
+	if node.LoadBalancer != nil {
+		return false
+	}
 
 	target := c.Targets[node.Resolver.Target]
 
diff --git a/api/discovery_chain.go b/api/discovery_chain.go
index 75fdbaee2..f67f881c2 100644
--- a/api/discovery_chain.go
+++ b/api/discovery_chain.go
@@ -147,6 +147,9 @@ type DiscoveryGraphNode struct {
 
 	// fields for Type==resolver
 	Resolver *DiscoveryResolver
+
+	// shared by Type==resolver || Type==splitter
+	LoadBalancer *LoadBalancer `json:",omitempty"`
 }
 
 // compiled form of ServiceRoute