swarm: network simulation for swarm tests (#769)

* cmd/swarm: minor cli flag text adjustments

* cmd/swarm, swarm/storage, swarm: fix  mingw on windows test issues

* cmd/swarm: support for smoke tests on the production swarm cluster

* cmd/swarm/swarm-smoke: simplify cluster logic as per suggestion

* changed colour of landing page

* landing page reacts to enter keypress

* swarm/api/http: sticky footer for swarm landing page using flex

* swarm/api/http: sticky footer for error pages and fix for multiple choices

* swarm: propagate ctx to internal apis (#754)

* swarm/simnet: add basic node/service functions

* swarm/netsim: add buckets for global state and kademlia health check

* swarm/netsim: Use sync.Map as bucket and provide cleanup function for...

* swarm, swarm/netsim: adjust SwarmNetworkTest

* swarm/netsim: fix tests

* swarm: added visualization option to sim net redesign

* swarm/netsim: support multiple services per node

* swarm/netsim: remove redundant return statement

* swarm/netsim: add comments

* swarm: shutdown HTTP in Simulation.Close

* swarm: sim HTTP server timeout

* swarm/netsim: add more simulation methods and peer events examples

* swarm/netsim: add WaitKademlia example

* swarm/netsim: fix comments

* swarm/netsim: terminate peer events goroutines on simulation done

* swarm, swarm/netsim: naming updates

* swarm/netsim: return not healthy kademlias on WaitTillHealthy

* swarm: fix WaitTillHealthy call in testSwarmNetwork

* swarm/netsim: allow bucket to have any type for a key

* swarm: Added snapshots to new netsim

* swarm/netsim: add more tests for bucket

* swarm/netsim: move http related things into separate files

* swarm/netsim: add AddNodeWithService option

* swarm/netsim: add more tests and Start* methods

* swarm/netsim: add peer events and kademlia tests

* swarm/netsim: fix some tests flakiness

* swarm/netsim: improve random nodes selection, fix TestStartStop* tests

* swarm/netsim: remove time measurement from TestClose to avoid flakiness

* swarm/netsim: builder pattern for netsim HTTP server (#773)

* swarm/netsim: add connect related tests

* swarm/netsim: add comment for TestPeerEvents

* swarm: rename netsim package to network/simulation

1 files changed, 306 insertions, 0 deletions

diff --git a/swarm/network/simulation/connect_test.go b/swarm/network/simulation/connect_test.go
new file mode 100644
index 000000000..10d73e4a1
--- /dev/null
+++ b/swarm/network/simulation/connect_test.go
@@ -0,0 +1,306 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package simulation
+
+import (
+	"testing"
+
+	"github.com/ethereum/go-ethereum/p2p/discover"
+)
+
+func TestConnectToPivotNode(t *testing.T) {
+	sim := New(noopServiceFuncMap)
+	defer sim.Close()
+
+	pid, err := sim.AddNode()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	sim.SetPivotNode(pid)
+
+	id, err := sim.AddNode()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(sim.Net.Conns) > 0 {
+		t.Fatal("no connections should exist after just adding nodes")
+	}
+
+	err = sim.ConnectToPivotNode(id)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if sim.Net.GetConn(id, pid) == nil {
+		t.Error("node did not connect to pivot node")
+	}
+}
+
+func TestConnectToLastNode(t *testing.T) {
+	sim := New(noopServiceFuncMap)
+	defer sim.Close()
+
+	n := 10
+
+	ids, err := sim.AddNodes(n)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	id, err := sim.AddNode()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(sim.Net.Conns) > 0 {
+		t.Fatal("no connections should exist after just adding nodes")
+	}
+
+	err = sim.ConnectToLastNode(id)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, i := range ids[:n-2] {
+		if sim.Net.GetConn(id, i) != nil {
+			t.Error("node connected to the node that is not the last")
+		}
+	}
+
+	if sim.Net.GetConn(id, ids[n-1]) == nil {
+		t.Error("node did not connect to the last node")
+	}
+}
+
+func TestConnectToRandomNode(t *testing.T) {
+	sim := New(noopServiceFuncMap)
+	defer sim.Close()
+
+	n := 10
+
+	ids, err := sim.AddNodes(n)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(sim.Net.Conns) > 0 {
+		t.Fatal("no connections should exist after just adding nodes")
+	}
+
+	err = sim.ConnectToRandomNode(ids[0])
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var cc int
+	for i := 0; i < n; i++ {
+		for j := i + 1; j < n; j++ {
+			if sim.Net.GetConn(ids[i], ids[j]) != nil {
+				cc++
+			}
+		}
+	}
+
+	if cc != 1 {
+		t.Errorf("expected one connection, got %v", cc)
+	}
+}
+
+func TestConnectNodesFull(t *testing.T) {
+	sim := New(noopServiceFuncMap)
+	defer sim.Close()
+
+	ids, err := sim.AddNodes(12)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(sim.Net.Conns) > 0 {
+		t.Fatal("no connections should exist after just adding nodes")
+	}
+
+	err = sim.ConnectNodesFull(ids)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	testFull(t, sim, ids)
+}
+
+func testFull(t *testing.T, sim *Simulation, ids []discover.NodeID) {
+	n := len(ids)
+	var cc int
+	for i := 0; i < n; i++ {
+		for j := i + 1; j < n; j++ {
+			if sim.Net.GetConn(ids[i], ids[j]) != nil {
+				cc++
+			}
+		}
+	}
+
+	want := n * (n - 1) / 2
+
+	if cc != want {
+		t.Errorf("expected %v connection, got %v", want, cc)
+	}
+}
+
+func TestConnectNodesChain(t *testing.T) {
+	sim := New(noopServiceFuncMap)
+	defer sim.Close()
+
+	ids, err := sim.AddNodes(10)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(sim.Net.Conns) > 0 {
+		t.Fatal("no connections should exist after just adding nodes")
+	}
+
+	err = sim.ConnectNodesChain(ids)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	testChain(t, sim, ids)
+}
+
+func testChain(t *testing.T, sim *Simulation, ids []discover.NodeID) {
+	n := len(ids)
+	for i := 0; i < n; i++ {
+		for j := i + 1; j < n; j++ {
+			c := sim.Net.GetConn(ids[i], ids[j])
+			if i == j-1 {
+				if c == nil {
+					t.Errorf("nodes %v and %v are not connected, but they should be", i, j)
+				}
+			} else {
+				if c != nil {
+					t.Errorf("nodes %v and %v are connected, but they should not be", i, j)
+				}
+			}
+		}
+	}
+}
+
+func TestConnectNodesRing(t *testing.T) {
+	sim := New(noopServiceFuncMap)
+	defer sim.Close()
+
+	ids, err := sim.AddNodes(10)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(sim.Net.Conns) > 0 {
+		t.Fatal("no connections should exist after just adding nodes")
+	}
+
+	err = sim.ConnectNodesRing(ids)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	testRing(t, sim, ids)
+}
+
+func testRing(t *testing.T, sim *Simulation, ids []discover.NodeID) {
+	n := len(ids)
+	for i := 0; i < n; i++ {
+		for j := i + 1; j < n; j++ {
+			c := sim.Net.GetConn(ids[i], ids[j])
+			if i == j-1 || (i == 0 && j == n-1) {
+				if c == nil {
+					t.Errorf("nodes %v and %v are not connected, but they should be", i, j)
+				}
+			} else {
+				if c != nil {
+					t.Errorf("nodes %v and %v are connected, but they should not be", i, j)
+				}
+			}
+		}
+	}
+}
+
+func TestConnectToNodesStar(t *testing.T) {
+	sim := New(noopServiceFuncMap)
+	defer sim.Close()
+
+	ids, err := sim.AddNodes(10)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(sim.Net.Conns) > 0 {
+		t.Fatal("no connections should exist after just adding nodes")
+	}
+
+	centerIndex := 2
+
+	err = sim.ConnectNodesStar(ids[centerIndex], ids)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	testStar(t, sim, ids, centerIndex)
+}
+
+func testStar(t *testing.T, sim *Simulation, ids []discover.NodeID, centerIndex int) {
+	n := len(ids)
+	for i := 0; i < n; i++ {
+		for j := i + 1; j < n; j++ {
+			c := sim.Net.GetConn(ids[i], ids[j])
+			if i == centerIndex || j == centerIndex {
+				if c == nil {
+					t.Errorf("nodes %v and %v are not connected, but they should be", i, j)
+				}
+			} else {
+				if c != nil {
+					t.Errorf("nodes %v and %v are connected, but they should not be", i, j)
+				}
+			}
+		}
+	}
+}
+
+func TestConnectToNodesStarPivot(t *testing.T) {
+	sim := New(noopServiceFuncMap)
+	defer sim.Close()
+
+	ids, err := sim.AddNodes(10)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(sim.Net.Conns) > 0 {
+		t.Fatal("no connections should exist after just adding nodes")
+	}
+
+	pivotIndex := 4
+
+	sim.SetPivotNode(ids[pivotIndex])
+
+	err = sim.ConnectNodesStarPivot(ids)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	testStar(t, sim, ids, pivotIndex)
+}