From fa781e6bb78b04887a21fdb22e7146ea8c50db08 Mon Sep 17 00:00:00 2001
From: Callum Waters <cmwaters19@gmail.com>
Date: Mon, 15 Mar 2021 13:04:33 +0100
Subject: [PATCH] e2e: fix light client generator (#6236)

---
 light/client.go                | 16 +++++++------
 test/e2e/app/main.go           |  8 ++++++-
 test/e2e/generator/generate.go | 42 ++++++++++++++++++++--------------
 3 files changed, 41 insertions(+), 25 deletions(-)

diff --git a/light/client.go b/light/client.go
index 86f257157..b6785f768 100644
--- a/light/client.go
+++ b/light/client.go
@@ -1101,14 +1101,16 @@ func (c *Client) compareFirstHeaderWithWitnesses(ctx context.Context, h *types.S
 and remove witness. Otherwise, use a different primary`, e.WitnessIndex), "witness", c.witnesses[e.WitnessIndex])
 			return err
 		case errBadWitness:
-			// If witness sent us an invalid header, then remove it. If it didn't
-			// respond or couldn't find the block, then we ignore it and move on to
-			// the next witness.
-			if _, ok := e.Reason.(provider.ErrBadLightBlock); ok {
-				c.logger.Info("Witness sent an invalid light block, removing...", "witness", c.witnesses[e.WitnessIndex])
-				witnessesToRemove = append(witnessesToRemove, e.WitnessIndex)
-			}
+			// If witness sent us an invalid header, then remove it
+			c.logger.Info("witness sent an invalid light block or didn't respond, removing...",
+				"witness", c.witnesses[e.WitnessIndex],
+				"err", err)
+			witnessesToRemove = append(witnessesToRemove, e.WitnessIndex)
+		default: // the witness either didn't respond or didn't have the block. We ignore it.
+			c.logger.Debug("unable to compare first header with witness",
+				"err", err)
 		}
+
 	}
 
 	// remove all witnesses that misbehaved
diff --git a/test/e2e/app/main.go b/test/e2e/app/main.go
index 25660ec44..a465bb786 100644
--- a/test/e2e/app/main.go
+++ b/test/e2e/app/main.go
@@ -349,7 +349,13 @@ func rpcEndpoints(peers string) []string {
 		}
 		// use RPC port instead
 		addr.Port = 26657
-		rpcEndpoint := "http://" + addr.Hostname + ":" + fmt.Sprint(addr.Port)
+		var rpcEndpoint string
+		// for ipv6 addresses
+		if strings.Contains(addr.Hostname, ":") {
+			rpcEndpoint = "http://[" + addr.Hostname + "]:" + fmt.Sprint(addr.Port)
+		} else { // for ipv4 addresses
+			rpcEndpoint = "http://" + addr.Hostname + ":" + fmt.Sprint(addr.Port)
+		}
 		endpoints[i] = rpcEndpoint
 	}
 	return endpoints
diff --git a/test/e2e/generator/generate.go b/test/e2e/generator/generate.go
index 85646bd74..29614fa3c 100644
--- a/test/e2e/generator/generate.go
+++ b/test/e2e/generator/generate.go
@@ -144,21 +144,19 @@ func generateTestnet(r *rand.Rand, opt map[string]interface{}) (e2e.Manifest, er
 			r, e2e.ModeFull, startAt, manifest.InitialHeight, false)
 	}
 
-	for i := 1; i <= numLightClients; i++ {
-		startAt := manifest.InitialHeight + 5
-		manifest.Nodes[fmt.Sprintf("light%02d", i)] = generateNode(
-			r, e2e.ModeLight, startAt+(5*int64(i)), manifest.InitialHeight, false,
-		)
-	}
-
 	// We now set up peer discovery for nodes. Seed nodes are fully meshed with
 	// each other, while non-seed nodes either use a set of random seeds or a
 	// set of random peers that start before themselves.
-	var seedNames, peerNames []string
+	var seedNames, peerNames, lightProviders []string
 	for name, node := range manifest.Nodes {
 		if node.Mode == string(e2e.ModeSeed) {
 			seedNames = append(seedNames, name)
 		} else {
+			// if the full node or validator is an ideal candidate, it is added as a light provider.
+			// There are at least two archive nodes so there should be at least two ideal candidates
+			if (node.StartAt == 0 || node.StartAt == manifest.InitialHeight) && node.RetainBlocks == 0 {
+				lightProviders = append(lightProviders, name)
+			}
 			peerNames = append(peerNames, name)
 		}
 	}
@@ -183,10 +181,6 @@ func generateTestnet(r *rand.Rand, opt map[string]interface{}) (e2e.Manifest, er
 		}
 	})
 	for i, name := range peerNames {
-		// we skip over light clients - they connect to all peers initially
-		if manifest.Nodes[name].Mode == string(e2e.ModeLight) {
-			continue
-		}
 		if len(seedNames) > 0 && (i == 0 || r.Float64() >= 0.5) {
 			manifest.Nodes[name].Seeds = uniformSetChoice(seedNames).Choose(r)
 		} else if i > 0 {
@@ -194,6 +188,14 @@ func generateTestnet(r *rand.Rand, opt map[string]interface{}) (e2e.Manifest, er
 		}
 	}
 
+	// lastly, set up the light clients
+	for i := 1; i <= numLightClients; i++ {
+		startAt := manifest.InitialHeight + 5
+		manifest.Nodes[fmt.Sprintf("light%02d", i)] = generateLightNode(
+			r, startAt+(5*int64(i)), lightProviders,
+		)
+	}
+
 	return manifest, nil
 }
 
@@ -236,11 +238,6 @@ func generateNode(
 		}
 	}
 
-	if node.Mode == string(e2e.ModeLight) {
-		node.ABCIProtocol = "builtin"
-		node.StateSync = false
-	}
-
 	// If a node which does not persist state also does not retain blocks, randomly
 	// choose to either persist state or retain all blocks.
 	if node.PersistInterval != nil && *node.PersistInterval == 0 && node.RetainBlocks > 0 {
@@ -265,6 +262,17 @@ func generateNode(
 	return &node
 }
 
+func generateLightNode(r *rand.Rand, startAt int64, providers []string) *e2e.ManifestNode {
+	return &e2e.ManifestNode{
+		Mode:            string(e2e.ModeLight),
+		StartAt:         startAt,
+		Database:        nodeDatabases.Choose(r).(string),
+		ABCIProtocol:    "builtin",
+		PersistInterval: ptrUint64(0),
+		PersistentPeers: providers,
+	}
+}
+
 func ptrUint64(i uint64) *uint64 {
 	return &i
 }