package xds

import (
	"bytes"
	"path/filepath"
	"sort"
	"testing"
	"text/template"

	envoy_cluster_v3 "github.com/envoyproxy/go-control-plane/envoy/config/cluster/v3"

	"github.com/golang/protobuf/ptypes/wrappers"
	testinf "github.com/mitchellh/go-testing-interface"
	"github.com/stretchr/testify/require"

	"github.com/hashicorp/consul/agent/proxycfg"
	"github.com/hashicorp/consul/agent/structs"
	"github.com/hashicorp/consul/agent/xds/proxysupport"
	"github.com/hashicorp/consul/agent/xds/xdscommon"
	"github.com/hashicorp/consul/sdk/testutil"
	"github.com/hashicorp/consul/types"
)

func TestClustersFromSnapshot(t *testing.T) {
	// TODO: we should move all of these to TestAllResourcesFromSnapshot
	// eventually to test all of the xDS types at once with the same input,
	// just as it would be triggered by our xDS server.
	if testing.Short() {
		t.Skip("too slow for testing.Short")
	}

	tests := []struct {
		name               string
		create             func(t testinf.T) *proxycfg.ConfigSnapshot
		overrideGoldenName string
	}{
		{
			name: "connect-proxy-with-tls-outgoing-min-version-auto",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, nil, []proxycfg.UpdateEvent{
					{
						CorrelationID: "mesh",
						Result: &structs.ConfigEntryResponse{
							Entry: &structs.MeshConfigEntry{
								TLS: &structs.MeshTLSConfig{
									Outgoing: &structs.MeshDirectionalTLSConfig{
										TLSMinVersion: types.TLSVersionAuto,
									},
								},
							},
						},
					},
				})
			},
		},
		{
			name: "connect-proxy-with-tls-outgoing-min-version",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, nil, []proxycfg.UpdateEvent{
					{
						CorrelationID: "mesh",
						Result: &structs.ConfigEntryResponse{
							Entry: &structs.MeshConfigEntry{
								TLS: &structs.MeshTLSConfig{
									Outgoing: &structs.MeshDirectionalTLSConfig{
										TLSMinVersion: types.TLSv1_3,
									},
								},
							},
						},
					},
				})
			},
		},
		{
			name: "connect-proxy-with-tls-outgoing-max-version",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, nil, []proxycfg.UpdateEvent{
					{
						CorrelationID: "mesh",
						Result: &structs.ConfigEntryResponse{
							Entry: &structs.MeshConfigEntry{
								TLS: &structs.MeshTLSConfig{
									Outgoing: &structs.MeshDirectionalTLSConfig{
										TLSMaxVersion: types.TLSv1_2,
									},
								},
							},
						},
					},
				})
			},
		},
		{
			name: "connect-proxy-with-tls-outgoing-cipher-suites",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, nil, []proxycfg.UpdateEvent{
					{
						CorrelationID: "mesh",
						Result: &structs.ConfigEntryResponse{
							Entry: &structs.MeshConfigEntry{
								TLS: &structs.MeshTLSConfig{
									Outgoing: &structs.MeshDirectionalTLSConfig{
										CipherSuites: []types.TLSCipherSuite{
											types.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
											types.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
										},
									},
								},
							},
						},
					},
				})
			},
		},
		{
			name: "custom-local-app",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, func(ns *structs.NodeService) {
					ns.Proxy.Config["envoy_local_cluster_json"] =
						customAppClusterJSON(t, customClusterJSONOptions{
							Name: "mylocal",
						})
				}, nil)
			},
		},
		{
			name: "custom-upstream",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, func(ns *structs.NodeService) {
					ns.Proxy.Upstreams[0].Config["envoy_cluster_json"] =
						customAppClusterJSON(t, customClusterJSONOptions{
							Name: "myservice",
						})
				}, nil)
			},
		},
		{
			name: "custom-upstream-default-chain",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "default", func(ns *structs.NodeService) {
					ns.Proxy.Upstreams[0].Config["envoy_cluster_json"] =
						customAppClusterJSON(t, customClusterJSONOptions{
							Name: "myservice",
						})
				}, nil)
			},
		},
		{
			name:               "custom-upstream-ignores-tls",
			overrideGoldenName: "custom-upstream", // should be the same
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, func(ns *structs.NodeService) {
					ns.Proxy.Upstreams[0].Config["envoy_cluster_json"] =
						customAppClusterJSON(t, customClusterJSONOptions{
							Name: "myservice",
							// Attempt to override the TLS context should be ignored
							TLSContext: `"allowRenegotiation": false`,
						})
				}, nil)
			},
		},
		{
			name: "custom-timeouts",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, func(ns *structs.NodeService) {
					ns.Proxy.Config["local_connect_timeout_ms"] = 1234
					ns.Proxy.Upstreams[0].Config["connect_timeout_ms"] = 2345
				}, nil)
			},
		},
		{
			name: "custom-max-inbound-connections",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, func(ns *structs.NodeService) {
					ns.Proxy.Config["max_inbound_connections"] = 3456
				}, nil)
			},
		},
		{
			name: "custom-limits-max-connections-only",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, func(ns *structs.NodeService) {
					for i := range ns.Proxy.Upstreams {
						// We check if Config is nil because the prepared_query upstream is
						// initialized without a Config map. Use Upstreams[i] syntax to
						// modify the actual ConfigSnapshot instead of copying the Upstream
						// in the range.
						if ns.Proxy.Upstreams[i].Config == nil {
							ns.Proxy.Upstreams[i].Config = map[string]interface{}{}
						}

						ns.Proxy.Upstreams[i].Config["limits"] = map[string]interface{}{
							"max_connections": 500,
						}
					}
				}, nil)
			},
		},
		{
			name: "custom-limits-set-to-zero",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, func(ns *structs.NodeService) {
					for i := range ns.Proxy.Upstreams {
						if ns.Proxy.Upstreams[i].Config == nil {
							ns.Proxy.Upstreams[i].Config = map[string]interface{}{}
						}

						ns.Proxy.Upstreams[i].Config["limits"] = map[string]interface{}{
							"max_connections":         0,
							"max_pending_requests":    0,
							"max_concurrent_requests": 0,
						}
					}
				}, nil)
			},
		},
		{
			name: "custom-limits",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, func(ns *structs.NodeService) {
					for i := range ns.Proxy.Upstreams {
						if ns.Proxy.Upstreams[i].Config == nil {
							ns.Proxy.Upstreams[i].Config = map[string]interface{}{}
						}

						ns.Proxy.Upstreams[i].Config["limits"] = map[string]interface{}{
							"max_connections":         500,
							"max_pending_requests":    600,
							"max_concurrent_requests": 700,
						}
					}
				}, nil)
			},
		},
		{
			name: "connect-proxy-with-chain",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "simple", nil, nil)
			},
		},
		{
			name: "connect-proxy-with-chain-external-sni",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "external-sni", nil, nil)
			},
		},
		{
			name: "connect-proxy-with-chain-and-overrides",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "simple-with-overrides", nil, nil)
			},
		},
		{
			name: "connect-proxy-with-chain-and-failover",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "failover", nil, nil)
			},
		},
		{
			name: "connect-proxy-with-tcp-chain-failover-through-remote-gateway",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "failover-through-remote-gateway", nil, nil)
			},
		},
		{
			name: "connect-proxy-with-tcp-chain-failover-through-remote-gateway-triggered",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "failover-through-remote-gateway-triggered", nil, nil)
			},
		},
		{
			name: "connect-proxy-with-tcp-chain-double-failover-through-remote-gateway",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "failover-through-double-remote-gateway", nil, nil)
			},
		},
		{
			name: "connect-proxy-with-tcp-chain-double-failover-through-remote-gateway-triggered",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "failover-through-double-remote-gateway-triggered", nil, nil)
			},
		},
		{
			name: "connect-proxy-with-tcp-chain-failover-through-local-gateway",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "failover-through-local-gateway", nil, nil)
			},
		},
		{
			name: "connect-proxy-with-tcp-chain-failover-through-local-gateway-triggered",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "failover-through-local-gateway-triggered", nil, nil)
			},
		},
		{
			name: "connect-proxy-with-tcp-chain-double-failover-through-local-gateway",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "failover-through-double-local-gateway", nil, nil)
			},
		},
		{
			name: "connect-proxy-with-tcp-chain-double-failover-through-local-gateway-triggered",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "failover-through-double-local-gateway-triggered", nil, nil)
			},
		},
		{
			name: "splitter-with-resolver-redirect",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "splitter-with-resolver-redirect-multidc", nil, nil)
			},
		},
		{
			name: "connect-proxy-lb-in-resolver",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotDiscoveryChain(t, "lb-resolver", nil, nil)
			},
		},
		{
			name: "expose-paths-local-app-paths",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotExposeConfig(t, nil)
			},
		},
		{
			name: "downstream-service-with-unix-sockets",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshot(t, func(ns *structs.NodeService) {
					ns.Address = ""
					ns.Port = 0
					ns.Proxy.LocalServiceAddress = ""
					ns.Proxy.LocalServicePort = 0
					ns.Proxy.LocalServiceSocketPath = "/tmp/downstream_proxy.sock"
				}, nil)
			},
		},
		{
			name: "expose-paths-new-cluster-http2",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotExposeConfig(t, func(ns *structs.NodeService) {
					ns.Proxy.Expose.Paths[1] = structs.ExposePath{
						LocalPathPort: 9090,
						Path:          "/grpc.health.v1.Health/Check",
						ListenerPort:  21501,
						Protocol:      "http2",
					}
				})
			},
		},
		{
			name:   "expose-paths-grpc-new-cluster-http1",
			create: proxycfg.TestConfigSnapshotGRPCExposeHTTP1,
		},
		{
			name: "mesh-gateway",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotMeshGateway(t, "default", nil, nil)
			},
		},
		{
			name: "mesh-gateway-using-federation-states",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotMeshGateway(t, "federation-states", nil, nil)
			},
		},
		{
			name: "mesh-gateway-no-services",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotMeshGateway(t, "no-services", nil, nil)
			},
		},
		{
			name: "mesh-gateway-service-subsets",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotMeshGateway(t, "service-subsets", nil, nil)
			},
		},
		{
			name: "mesh-gateway-ignore-extra-resolvers",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotMeshGateway(t, "ignore-extra-resolvers", nil, nil)
			},
		},
		{
			name: "mesh-gateway-service-timeouts",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotMeshGateway(t, "service-timeouts", nil, nil)
			},
		},
		{
			name: "mesh-gateway-non-hash-lb-injected",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotMeshGateway(t, "non-hash-lb-injected", nil, nil)
			},
		},
		{
			name: "mesh-gateway-hash-lb-ignored",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotMeshGateway(t, "hash-lb-ignored", nil, nil)
			},
		},
		{
			name: "ingress-gateway",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"default", nil, nil, nil)
			},
		},
		{
			name: "ingress-gateway-with-tls-outgoing-min-version",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp", "default", nil, nil, []proxycfg.UpdateEvent{
					{
						CorrelationID: "mesh",
						Result: &structs.ConfigEntryResponse{
							Entry: &structs.MeshConfigEntry{
								TLS: &structs.MeshTLSConfig{
									Outgoing: &structs.MeshDirectionalTLSConfig{
										TLSMinVersion: types.TLSv1_3,
									},
								},
							},
						},
					},
				})
			},
		},
		{
			name: "ingress-gateway-with-tls-outgoing-max-version",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp", "default", nil, nil, []proxycfg.UpdateEvent{
					{
						CorrelationID: "mesh",
						Result: &structs.ConfigEntryResponse{
							Entry: &structs.MeshConfigEntry{
								TLS: &structs.MeshTLSConfig{
									Outgoing: &structs.MeshDirectionalTLSConfig{
										TLSMaxVersion: types.TLSv1_2,
									},
								},
							},
						},
					},
				})
			},
		},
		{
			name: "ingress-gateway-with-tls-outgoing-cipher-suites",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp", "default", nil, nil, []proxycfg.UpdateEvent{
					{
						CorrelationID: "mesh",
						Result: &structs.ConfigEntryResponse{
							Entry: &structs.MeshConfigEntry{
								TLS: &structs.MeshTLSConfig{
									Outgoing: &structs.MeshDirectionalTLSConfig{
										CipherSuites: []types.TLSCipherSuite{
											types.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
											types.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
										},
									},
								},
							},
						},
					},
				})
			},
		},
		{
			name: "ingress-gateway-no-services",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, false, "tcp",
					"default", nil, nil, nil)
			},
		},
		{
			name: "ingress-with-chain",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"simple", nil, nil, nil)
			},
		},
		{
			name: "ingress-with-chain-external-sni",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"external-sni", nil, nil, nil)
			},
		},
		{
			name: "ingress-with-chain-and-failover",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"failover", nil, nil, nil)
			},
		},
		{
			name: "ingress-with-tcp-chain-failover-through-remote-gateway",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"failover-through-remote-gateway", nil, nil, nil)
			},
		},
		{
			name: "ingress-with-tcp-chain-failover-through-remote-gateway-triggered",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"failover-through-remote-gateway-triggered", nil, nil, nil)
			},
		},
		{
			name: "ingress-with-tcp-chain-double-failover-through-remote-gateway",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"failover-through-double-remote-gateway", nil, nil, nil)
			},
		},
		{
			name: "ingress-with-tcp-chain-double-failover-through-remote-gateway-triggered",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"failover-through-double-remote-gateway-triggered", nil, nil, nil)
			},
		},
		{
			name: "ingress-with-tcp-chain-failover-through-local-gateway",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"failover-through-local-gateway", nil, nil, nil)
			},
		},
		{
			name: "ingress-with-tcp-chain-failover-through-local-gateway-triggered",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"failover-through-local-gateway-triggered", nil, nil, nil)
			},
		},
		{
			name: "ingress-with-tcp-chain-double-failover-through-local-gateway",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"failover-through-double-local-gateway", nil, nil, nil)
			},
		},
		{
			name: "ingress-with-tcp-chain-double-failover-through-local-gateway-triggered",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "tcp",
					"failover-through-double-local-gateway-triggered", nil, nil, nil)
			},
		},
		{
			name: "ingress-splitter-with-resolver-redirect",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "http",
					"splitter-with-resolver-redirect-multidc", nil, nil, nil)
			},
		},
		{
			name: "ingress-lb-in-resolver",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotIngressGateway(t, true, "http",
					"lb-resolver", nil, nil, nil)
			},
		},
		{
			name: "terminating-gateway",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotTerminatingGateway(t, true, nil, nil)
			},
		},
		{
			name: "terminating-gateway-no-services",
			create: func(t testinf.T) *proxycfg.ConfigSnapshot {
				return proxycfg.TestConfigSnapshotTerminatingGateway(t, false, nil, nil)
			},
		},
		{
			name:   "terminating-gateway-service-subsets",
			create: proxycfg.TestConfigSnapshotTerminatingGatewayServiceSubsetsWebAndCache,
		},
		{
			name:   "terminating-gateway-hostname-service-subsets",
			create: proxycfg.TestConfigSnapshotTerminatingGatewayHostnameSubsets,
		},
		{
			name:   "terminating-gateway-sni",
			create: proxycfg.TestConfigSnapshotTerminatingGatewaySNI,
		},
		{
			name:   "terminating-gateway-http2-upstream",
			create: proxycfg.TestConfigSnapshotTerminatingGatewayHTTP2,
		},
		{
			name:   "terminating-gateway-http2-upstream-subsets",
			create: proxycfg.TestConfigSnapshotTerminatingGatewaySubsetsHTTP2,
		},
		{
			name:   "terminating-gateway-ignore-extra-resolvers",
			create: proxycfg.TestConfigSnapshotTerminatingGatewayIgnoreExtraResolvers,
		},
		{
			name:   "terminating-gateway-lb-config",
			create: proxycfg.TestConfigSnapshotTerminatingGatewayLBConfigNoHashPolicies,
		},
		{
			name:   "ingress-multiple-listeners-duplicate-service",
			create: proxycfg.TestConfigSnapshotIngress_MultipleListenersDuplicateService,
		},
		{
			name:   "transparent-proxy-catalog-destinations-only",
			create: proxycfg.TestConfigSnapshotTransparentProxyCatalogDestinationsOnly,
		},
		{
			name:   "transparent-proxy-dial-instances-directly",
			create: proxycfg.TestConfigSnapshotTransparentProxyDialDirectly,
		},
	}

	latestEnvoyVersion := proxysupport.EnvoyVersions[0]
	for _, envoyVersion := range proxysupport.EnvoyVersions {
		sf, err := determineSupportedProxyFeaturesFromString(envoyVersion)
		require.NoError(t, err)
		t.Run("envoy-"+envoyVersion, func(t *testing.T) {
			for _, tt := range tests {
				t.Run(tt.name, func(t *testing.T) {
					// Sanity check default with no overrides first
					snap := tt.create(t)

					// We need to replace the TLS certs with deterministic ones to make golden
					// files workable. Note we don't update these otherwise they'd change
					// golder files for every test case and so not be any use!
					setupTLSRootsAndLeaf(t, snap)

					// Need server just for logger dependency
					g := newResourceGenerator(testutil.Logger(t), nil, false)
					g.ProxyFeatures = sf

					clusters, err := g.clustersFromSnapshot(snap)
					require.NoError(t, err)

					sort.Slice(clusters, func(i, j int) bool {
						return clusters[i].(*envoy_cluster_v3.Cluster).Name < clusters[j].(*envoy_cluster_v3.Cluster).Name
					})

					r, err := createResponse(xdscommon.ClusterType, "00000001", "00000001", clusters)
					require.NoError(t, err)

					t.Run("current", func(t *testing.T) {
						gotJSON := protoToJSON(t, r)

						gName := tt.name
						if tt.overrideGoldenName != "" {
							gName = tt.overrideGoldenName
						}

						require.JSONEq(t, goldenEnvoy(t, filepath.Join("clusters", gName), envoyVersion, latestEnvoyVersion, gotJSON), gotJSON)
					})
				})
			}
		})
	}
}

type customClusterJSONOptions struct {
	Name       string
	TLSContext string
}

var customAppClusterJSONTpl = `{
	"@type": "type.googleapis.com/envoy.config.cluster.v3.Cluster",
	{{ if .TLSContext -}}
	"transport_socket": {
		"name": "tls",
		"typed_config": {
			"@type": "type.googleapis.com/envoy.extensions.transport_sockets.tls.v3.UpstreamTlsContext",
			{{ .TLSContext }}
		}
	},
	{{- end }}
	"name": "{{ .Name }}",
	"connectTimeout": "15s",
	"loadAssignment": {
		"clusterName": "{{ .Name }}",
		"endpoints": [
			{
				"lbEndpoints": [
					{
						"endpoint": {
							"address": {
								"socketAddress": {
									"address": "127.0.0.1",
									"portValue": 8080
								}
							}
						}
					}
				]
			}
		]
	}
}`

var customAppClusterJSONTemplate = template.Must(template.New("").Parse(customAppClusterJSONTpl))

func customAppClusterJSON(t testinf.T, opts customClusterJSONOptions) string {
	t.Helper()
	var buf bytes.Buffer
	err := customAppClusterJSONTemplate.Execute(&buf, opts)
	require.NoError(t, err)
	return buf.String()
}

func setupTLSRootsAndLeaf(t *testing.T, snap *proxycfg.ConfigSnapshot) {
	if snap.Leaf() != nil {
		switch snap.Kind {
		case structs.ServiceKindConnectProxy:
			snap.ConnectProxy.Leaf.CertPEM = loadTestResource(t, "test-leaf-cert")
			snap.ConnectProxy.Leaf.PrivateKeyPEM = loadTestResource(t, "test-leaf-key")
		case structs.ServiceKindIngressGateway:
			snap.IngressGateway.Leaf.CertPEM = loadTestResource(t, "test-leaf-cert")
			snap.IngressGateway.Leaf.PrivateKeyPEM = loadTestResource(t, "test-leaf-key")
		case structs.ServiceKindMeshGateway:
			snap.MeshGateway.Leaf.CertPEM = loadTestResource(t, "test-leaf-cert")
			snap.MeshGateway.Leaf.PrivateKeyPEM = loadTestResource(t, "test-leaf-key")
		}
	}
	if snap.Roots != nil {
		snap.Roots.Roots[0].RootCert = loadTestResource(t, "test-root-cert")
	}
}

func TestEnvoyLBConfig_InjectToCluster(t *testing.T) {
	var tests = []struct {
		name     string
		lb       *structs.LoadBalancer
		expected *envoy_cluster_v3.Cluster
	}{
		{
			name: "skip empty",
			lb: &structs.LoadBalancer{
				Policy: "",
			},
			expected: &envoy_cluster_v3.Cluster{},
		},
		{
			name: "round robin",
			lb: &structs.LoadBalancer{
				Policy: structs.LBPolicyRoundRobin,
			},
			expected: &envoy_cluster_v3.Cluster{LbPolicy: envoy_cluster_v3.Cluster_ROUND_ROBIN},
		},
		{
			name: "random",
			lb: &structs.LoadBalancer{
				Policy: structs.LBPolicyRandom,
			},
			expected: &envoy_cluster_v3.Cluster{LbPolicy: envoy_cluster_v3.Cluster_RANDOM},
		},
		{
			name: "maglev",
			lb: &structs.LoadBalancer{
				Policy: structs.LBPolicyMaglev,
			},
			expected: &envoy_cluster_v3.Cluster{LbPolicy: envoy_cluster_v3.Cluster_MAGLEV},
		},
		{
			name: "ring_hash",
			lb: &structs.LoadBalancer{
				Policy: structs.LBPolicyRingHash,
				RingHashConfig: &structs.RingHashConfig{
					MinimumRingSize: 3,
					MaximumRingSize: 7,
				},
			},
			expected: &envoy_cluster_v3.Cluster{
				LbPolicy: envoy_cluster_v3.Cluster_RING_HASH,
				LbConfig: &envoy_cluster_v3.Cluster_RingHashLbConfig_{
					RingHashLbConfig: &envoy_cluster_v3.Cluster_RingHashLbConfig{
						MinimumRingSize: &wrappers.UInt64Value{Value: 3},
						MaximumRingSize: &wrappers.UInt64Value{Value: 7},
					},
				},
			},
		},
		{
			name: "least_request",
			lb: &structs.LoadBalancer{
				Policy: "least_request",
				LeastRequestConfig: &structs.LeastRequestConfig{
					ChoiceCount: 3,
				},
			},
			expected: &envoy_cluster_v3.Cluster{
				LbPolicy: envoy_cluster_v3.Cluster_LEAST_REQUEST,
				LbConfig: &envoy_cluster_v3.Cluster_LeastRequestLbConfig_{
					LeastRequestLbConfig: &envoy_cluster_v3.Cluster_LeastRequestLbConfig{
						ChoiceCount: &wrappers.UInt32Value{Value: 3},
					},
				},
			},
		},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			var c envoy_cluster_v3.Cluster
			err := injectLBToCluster(tc.lb, &c)
			require.NoError(t, err)

			require.Equal(t, tc.expected, &c)
		})
	}
}

// UID is just a convenience function to aid in writing tests less verbosely.
func UID(input string) proxycfg.UpstreamID {
	return proxycfg.UpstreamIDFromString(input)
}