From c749c6c92760f2dc3d4b07c4aff525b313be3a68 Mon Sep 17 00:00:00 2001
From: Daniel Nephin <dnephin@hashicorp.com>
Date: Tue, 16 Mar 2021 13:15:14 -0400
Subject: [PATCH] state: use constants for mesh-topology table operations

---
 agent/consul/state/catalog.go        | 14 +++++++-------
 agent/consul/state/catalog_schema.go | 10 ++++++----
 agent/consul/state/config_entry.go   |  2 +-
 3 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/agent/consul/state/catalog.go b/agent/consul/state/catalog.go
index e04f7ebc9c..df5ac87467 100644
--- a/agent/consul/state/catalog.go
+++ b/agent/consul/state/catalog.go
@@ -2992,9 +2992,9 @@ func downstreamsFromRegistrationTxn(tx ReadTxn, ws memdb.WatchSet, sn structs.Se
 func linkedFromRegistrationTxn(tx ReadTxn, ws memdb.WatchSet, service structs.ServiceName, downstreams bool) (uint64, []structs.ServiceName, error) {
 	// To fetch upstreams we query services that have the input listed as a downstream
 	// To fetch downstreams we query services that have the input listed as an upstream
-	index := "downstream"
+	index := indexDownstream
 	if downstreams {
-		index = "upstream"
+		index = indexUpstream
 	}
 
 	iter, err := tx.Get(tableMeshTopology, index, service)
@@ -3053,7 +3053,7 @@ func updateMeshTopology(tx WriteTxn, idx uint64, node string, svc *structs.NodeS
 		upstreamMeta := structs.NewEnterpriseMeta(u.DestinationNamespace)
 		upstream := structs.NewServiceName(u.DestinationName, &upstreamMeta)
 
-		obj, err := tx.First(tableMeshTopology, "id", upstream, downstream)
+		obj, err := tx.First(tableMeshTopology, indexID, upstream, downstream)
 		if err != nil {
 			return fmt.Errorf("%q lookup failed: %v", tableMeshTopology, err)
 		}
@@ -3097,7 +3097,7 @@ func updateMeshTopology(tx WriteTxn, idx uint64, node string, svc *structs.NodeS
 
 	for u := range oldUpstreams {
 		if !inserted[u] {
-			if _, err := tx.DeleteAll(tableMeshTopology, "id", u, downstream); err != nil {
+			if _, err := tx.DeleteAll(tableMeshTopology, indexID, u, downstream); err != nil {
 				return fmt.Errorf("failed to truncate %s table: %v", tableMeshTopology, err)
 			}
 			if err := indexUpdateMaxTxn(tx, idx, tableMeshTopology); err != nil {
@@ -3119,7 +3119,7 @@ func cleanupMeshTopology(tx WriteTxn, idx uint64, service *structs.ServiceNode)
 	sid := service.CompoundServiceID()
 	uid := structs.UniqueID(service.Node, sid.String())
 
-	iter, err := tx.Get(tableMeshTopology, "downstream", sn)
+	iter, err := tx.Get(tableMeshTopology, indexDownstream, sn)
 	if err != nil {
 		return fmt.Errorf("%q lookup failed: %v", tableMeshTopology, err)
 	}
@@ -3190,7 +3190,7 @@ func deleteGatewayServiceTopologyMapping(tx WriteTxn, idx uint64, gs *structs.Ga
 		return nil
 	}
 
-	if _, err := tx.DeleteAll(tableMeshTopology, "id", gs.Service, gs.Gateway); err != nil {
+	if _, err := tx.DeleteAll(tableMeshTopology, indexID, gs.Service, gs.Gateway); err != nil {
 		return fmt.Errorf("failed to truncate %s table: %v", tableMeshTopology, err)
 	}
 	if err := indexUpdateMaxTxn(tx, idx, tableMeshTopology); err != nil {
@@ -3206,7 +3206,7 @@ func truncateGatewayServiceTopologyMappings(tx WriteTxn, idx uint64, gateway str
 		return nil
 	}
 
-	if _, err := tx.DeleteAll(tableMeshTopology, "downstream", gateway); err != nil {
+	if _, err := tx.DeleteAll(tableMeshTopology, indexDownstream, gateway); err != nil {
 		return fmt.Errorf("failed to truncate %s table: %v", tableMeshTopology, err)
 	}
 	if err := indexUpdateMaxTxn(tx, idx, tableMeshTopology); err != nil {
diff --git a/agent/consul/state/catalog_schema.go b/agent/consul/state/catalog_schema.go
index 8769d1e75b..d0fdd0e798 100644
--- a/agent/consul/state/catalog_schema.go
+++ b/agent/consul/state/catalog_schema.go
@@ -24,6 +24,8 @@ const (
 	indexStatus      = "status"
 	indexNodeService = "node_service"
 	indexNode        = "node"
+	indexUpstream    = "upstream"
+	indexDownstream  = "downstream"
 )
 
 // nodesTableSchema returns a new table schema used for storing struct.Node.
@@ -245,16 +247,16 @@ func meshTopologyTableSchema() *memdb.TableSchema {
 					},
 				},
 			},
-			"upstream": {
-				Name:         "upstream",
+			indexUpstream: {
+				Name:         indexUpstream,
 				AllowMissing: true,
 				Unique:       false,
 				Indexer: &ServiceNameIndex{
 					Field: "Upstream",
 				},
 			},
-			"downstream": {
-				Name:         "downstream",
+			indexDownstream: {
+				Name:         indexDownstream,
 				AllowMissing: false,
 				Unique:       false,
 				Indexer: &ServiceNameIndex{
diff --git a/agent/consul/state/config_entry.go b/agent/consul/state/config_entry.go
index 41fe9f7520..2fabc2af5e 100644
--- a/agent/consul/state/config_entry.go
+++ b/agent/consul/state/config_entry.go
@@ -278,7 +278,7 @@ func deleteConfigEntryTxn(tx WriteTxn, idx uint64, kind, name string, entMeta *s
 	}
 	// Also clean up associations in the mesh topology table for ingress gateways
 	if kind == structs.IngressGateway {
-		if _, err := tx.DeleteAll(tableMeshTopology, "downstream", sn); err != nil {
+		if _, err := tx.DeleteAll(tableMeshTopology, indexDownstream, sn); err != nil {
 			return fmt.Errorf("failed to truncate %s table: %v", tableMeshTopology, err)
 		}
 		if err := indexUpdateMaxTxn(tx, idx, tableMeshTopology); err != nil {