test: add E2E test for node peering (#5465)

This was a missing test case from the old P2P tests removed in #5453, which makes sure that all nodes are able to peer with each other regardless of how they discover peers.

Fixes #2795, since the default CI testnet uses a combination of (partially meshed) persistent peers and PEX-based seed nodes.

test/e2e/Makefile

@@ -1,9 +1,8 @@
+all: docker runner
+
 docker:
 	docker build --tag tendermint/e2e-node -f docker/Dockerfile ../..
 
-ci: runner
-	./build/runner -f networks/ci.toml
-
 # We need to build support for database backends into the app in
 # order to build a binary with a Tendermint node in it (for built-in
 # ABCI testing).
@@ -13,4 +12,4 @@ app:
 runner:
 	go build -o build/runner ./runner
 
-.PHONY: app ci docker runner
+.PHONY: app docker runner

test/e2e/networks/ci.toml

@@ -26,6 +26,11 @@ validator05 = 50
 
 [node.seed01]
 mode = "seed"
+persistent_peers = ["seed02"]
+
+[node.seed02]
+mode = "seed"
+persistent_peers = ["seed01"]
 
 [node.validator01]
 seeds = ["seed01"]
@@ -33,7 +38,7 @@ snapshot_interval = 5
 perturb = ["disconnect"]
 
 [node.validator02]
-seeds = ["seed01"]
+seeds = ["seed02"]
 database = "boltdb"
 abci_protocol = "tcp"
 privval_protocol = "tcp"
@@ -64,7 +69,7 @@ perturb = ["pause"]
 
 [node.validator05]
 start_at = 1005 # Becomes part of the validator set at 1010
-seeds = ["seed01"]
+seeds = ["seed02"]
 database = "cleveldb"
 fast_sync = "v0"
 # FIXME Should use grpc, but it has race conditions

test/e2e/runner/main.go

@@ -68,7 +68,7 @@ func NewCLI() *CLI {
 			if err := Perturb(cli.testnet); err != nil {
 				return err
 			}
-			if err := Wait(cli.testnet, 5); err != nil { // wait for network to settle
+			if err := Wait(cli.testnet, 5); err != nil { // allow some txs to go through
 				return err
 			}
 
@@ -76,7 +76,7 @@ func NewCLI() *CLI {
 			if err := <-chLoadResult; err != nil {
 				return err
 			}
-			if err := Wait(cli.testnet, 3); err != nil { // wait for last txs to commit
+			if err := Wait(cli.testnet, 10); err != nil { // wait for network to settle before tests
 				return err
 			}
 			if err := Test(cli.testnet); err != nil {

test/e2e/tests/net_test.go

@@ -0,0 +1,42 @@
+package e2e_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	e2e "github.com/tendermint/tendermint/test/e2e/pkg"
+)
+
+// Tests that all nodes have peered with each other, regardless of discovery method.
+func TestNet_Peers(t *testing.T) {
+	testNode(t, func(t *testing.T, node e2e.Node) {
+		// Seed nodes shouldn't necessarily mesh with the entire network.
+		if node.Mode == e2e.ModeSeed {
+			return
+		}
+
+		client, err := node.Client()
+		require.NoError(t, err)
+		netInfo, err := client.NetInfo(ctx)
+		require.NoError(t, err)
+
+		require.Equal(t, len(node.Testnet.Nodes)-1, netInfo.NPeers,
+			"node is not fully meshed with peers")
+
+		seen := map[string]bool{}
+		for _, n := range node.Testnet.Nodes {
+			seen[n.Name] = (n.Name == node.Name) // we've clearly seen ourself
+		}
+		for _, peerInfo := range netInfo.Peers {
+			peer := node.Testnet.LookupNode(peerInfo.NodeInfo.Moniker)
+			require.NotNil(t, peer, "unknown node %v", peerInfo.NodeInfo.Moniker)
+			require.Equal(t, peer.IP.String(), peerInfo.RemoteIP,
+				"unexpected IP address for peer %v", peer.Name)
+			seen[peerInfo.NodeInfo.Moniker] = true
+		}
+
+		for name := range seen {
+			require.True(t, seen[name], "node %v not peered with %v", node.Name, name)
+		}
+	})
+}