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, 357 insertions, 0 deletions

diff --git a/swarm/network/simulation/node.go b/swarm/network/simulation/node.go
new file mode 100644
index 000000000..bc433cfd8
--- /dev/null
+++ b/swarm/network/simulation/node.go
@@ -0,0 +1,357 @@
+// 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 (
+	"encoding/json"
+	"errors"
+	"io/ioutil"
+	"math/rand"
+	"os"
+	"time"
+
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/p2p/simulations"
+	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
+)
+
+// NodeIDs returns NodeIDs for all nodes in the network.
+func (s *Simulation) NodeIDs() (ids []discover.NodeID) {
+	nodes := s.Net.GetNodes()
+	ids = make([]discover.NodeID, len(nodes))
+	for i, node := range nodes {
+		ids[i] = node.ID()
+	}
+	return ids
+}
+
+// UpNodeIDs returns NodeIDs for nodes that are up in the network.
+func (s *Simulation) UpNodeIDs() (ids []discover.NodeID) {
+	nodes := s.Net.GetNodes()
+	for _, node := range nodes {
+		if node.Up {
+			ids = append(ids, node.ID())
+		}
+	}
+	return ids
+}
+
+// DownNodeIDs returns NodeIDs for nodes that are stopped in the network.
+func (s *Simulation) DownNodeIDs() (ids []discover.NodeID) {
+	nodes := s.Net.GetNodes()
+	for _, node := range nodes {
+		if !node.Up {
+			ids = append(ids, node.ID())
+		}
+	}
+	return ids
+}
+
+// AddNodeOption defines the option that can be passed
+// to Simulation.AddNode method.
+type AddNodeOption func(*adapters.NodeConfig)
+
+// AddNodeWithMsgEvents sets the EnableMsgEvents option
+// to NodeConfig.
+func AddNodeWithMsgEvents(enable bool) AddNodeOption {
+	return func(o *adapters.NodeConfig) {
+		o.EnableMsgEvents = enable
+	}
+}
+
+// AddNodeWithService specifies a service that should be
+// started on a node. This option can be repeated as variadic
+// argument toe AddNode and other add node related methods.
+// If AddNodeWithService is not specified, all services will be started.
+func AddNodeWithService(serviceName string) AddNodeOption {
+	return func(o *adapters.NodeConfig) {
+		o.Services = append(o.Services, serviceName)
+	}
+}
+
+// AddNode creates a new node with random configuration,
+// applies provided options to the config and adds the node to network.
+// By default all services will be started on a node. If one or more
+// AddNodeWithService option are provided, only specified services will be started.
+func (s *Simulation) AddNode(opts ...AddNodeOption) (id discover.NodeID, err error) {
+	conf := adapters.RandomNodeConfig()
+	for _, o := range opts {
+		o(conf)
+	}
+	if len(conf.Services) == 0 {
+		conf.Services = s.serviceNames
+	}
+	node, err := s.Net.NewNodeWithConfig(conf)
+	if err != nil {
+		return id, err
+	}
+	return node.ID(), s.Net.Start(node.ID())
+}
+
+// AddNodes creates new nodes with random configurations,
+// applies provided options to the config and adds nodes to network.
+func (s *Simulation) AddNodes(count int, opts ...AddNodeOption) (ids []discover.NodeID, err error) {
+	ids = make([]discover.NodeID, 0, count)
+	for i := 0; i < count; i++ {
+		id, err := s.AddNode(opts...)
+		if err != nil {
+			return nil, err
+		}
+		ids = append(ids, id)
+	}
+	return ids, nil
+}
+
+// AddNodesAndConnectFull is a helpper method that combines
+// AddNodes and ConnectNodesFull. Only new nodes will be connected.
+func (s *Simulation) AddNodesAndConnectFull(count int, opts ...AddNodeOption) (ids []discover.NodeID, err error) {
+	if count < 2 {
+		return nil, errors.New("count of nodes must be at least 2")
+	}
+	ids, err = s.AddNodes(count, opts...)
+	if err != nil {
+		return nil, err
+	}
+	err = s.ConnectNodesFull(ids)
+	if err != nil {
+		return nil, err
+	}
+	return ids, nil
+}
+
+// AddNodesAndConnectChain is a helpper method that combines
+// AddNodes and ConnectNodesChain. The chain will be continued from the last
+// added node, if there is one in simulation using ConnectToLastNode method.
+func (s *Simulation) AddNodesAndConnectChain(count int, opts ...AddNodeOption) (ids []discover.NodeID, err error) {
+	if count < 2 {
+		return nil, errors.New("count of nodes must be at least 2")
+	}
+	id, err := s.AddNode(opts...)
+	if err != nil {
+		return nil, err
+	}
+	err = s.ConnectToLastNode(id)
+	if err != nil {
+		return nil, err
+	}
+	ids, err = s.AddNodes(count-1, opts...)
+	if err != nil {
+		return nil, err
+	}
+	ids = append([]discover.NodeID{id}, ids...)
+	err = s.ConnectNodesChain(ids)
+	if err != nil {
+		return nil, err
+	}
+	return ids, nil
+}
+
+// AddNodesAndConnectRing is a helpper method that combines
+// AddNodes and ConnectNodesRing.
+func (s *Simulation) AddNodesAndConnectRing(count int, opts ...AddNodeOption) (ids []discover.NodeID, err error) {
+	if count < 2 {
+		return nil, errors.New("count of nodes must be at least 2")
+	}
+	ids, err = s.AddNodes(count, opts...)
+	if err != nil {
+		return nil, err
+	}
+	err = s.ConnectNodesRing(ids)
+	if err != nil {
+		return nil, err
+	}
+	return ids, nil
+}
+
+// AddNodesAndConnectStar is a helpper method that combines
+// AddNodes and ConnectNodesStar.
+func (s *Simulation) AddNodesAndConnectStar(count int, opts ...AddNodeOption) (ids []discover.NodeID, err error) {
+	if count < 2 {
+		return nil, errors.New("count of nodes must be at least 2")
+	}
+	ids, err = s.AddNodes(count, opts...)
+	if err != nil {
+		return nil, err
+	}
+	err = s.ConnectNodesStar(ids[0], ids[1:])
+	if err != nil {
+		return nil, err
+	}
+	return ids, nil
+}
+
+//Upload a snapshot
+//This method tries to open the json file provided, applies the config to all nodes
+//and then loads the snapshot into the Simulation network
+func (s *Simulation) UploadSnapshot(snapshotFile string, opts ...AddNodeOption) error {
+	f, err := os.Open(snapshotFile)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	jsonbyte, err := ioutil.ReadAll(f)
+	if err != nil {
+		return err
+	}
+	var snap simulations.Snapshot
+	err = json.Unmarshal(jsonbyte, &snap)
+	if err != nil {
+		return err
+	}
+
+	//the snapshot probably has the property EnableMsgEvents not set
+	//just in case, set it to true!
+	//(we need this to wait for messages before uploading)
+	for _, n := range snap.Nodes {
+		n.Node.Config.EnableMsgEvents = true
+		n.Node.Config.Services = s.serviceNames
+		for _, o := range opts {
+			o(n.Node.Config)
+		}
+	}
+
+	log.Info("Waiting for p2p connections to be established...")
+
+	//now we can load the snapshot
+	err = s.Net.Load(&snap)
+	if err != nil {
+		return err
+	}
+	log.Info("Snapshot loaded")
+	return nil
+}
+
+// SetPivotNode sets the NodeID of the network's pivot node.
+// Pivot node is just a specific node that should be treated
+// differently then other nodes in test. SetPivotNode and
+// PivotNodeID are just a convenient functions to set and
+// retrieve it.
+func (s *Simulation) SetPivotNode(id discover.NodeID) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.pivotNodeID = &id
+}
+
+// PivotNodeID returns NodeID of the pivot node set by
+// Simulation.SetPivotNode method.
+func (s *Simulation) PivotNodeID() (id *discover.NodeID) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.pivotNodeID
+}
+
+// StartNode starts a node by NodeID.
+func (s *Simulation) StartNode(id discover.NodeID) (err error) {
+	return s.Net.Start(id)
+}
+
+// StartRandomNode starts a random node.
+func (s *Simulation) StartRandomNode() (id discover.NodeID, err error) {
+	n := s.randomDownNode()
+	if n == nil {
+		return id, ErrNodeNotFound
+	}
+	return n.ID, s.Net.Start(n.ID)
+}
+
+// StartRandomNodes starts random nodes.
+func (s *Simulation) StartRandomNodes(count int) (ids []discover.NodeID, err error) {
+	ids = make([]discover.NodeID, 0, count)
+	downIDs := s.DownNodeIDs()
+	for i := 0; i < count; i++ {
+		n := s.randomNode(downIDs, ids...)
+		if n == nil {
+			return nil, ErrNodeNotFound
+		}
+		err = s.Net.Start(n.ID)
+		if err != nil {
+			return nil, err
+		}
+		ids = append(ids, n.ID)
+	}
+	return ids, nil
+}
+
+// StopNode stops a node by NodeID.
+func (s *Simulation) StopNode(id discover.NodeID) (err error) {
+	return s.Net.Stop(id)
+}
+
+// StopRandomNode stops a random node.
+func (s *Simulation) StopRandomNode() (id discover.NodeID, err error) {
+	n := s.randomUpNode()
+	if n == nil {
+		return id, ErrNodeNotFound
+	}
+	return n.ID, s.Net.Stop(n.ID)
+}
+
+// StopRandomNodes stops random nodes.
+func (s *Simulation) StopRandomNodes(count int) (ids []discover.NodeID, err error) {
+	ids = make([]discover.NodeID, 0, count)
+	upIDs := s.UpNodeIDs()
+	for i := 0; i < count; i++ {
+		n := s.randomNode(upIDs, ids...)
+		if n == nil {
+			return nil, ErrNodeNotFound
+		}
+		err = s.Net.Stop(n.ID)
+		if err != nil {
+			return nil, err
+		}
+		ids = append(ids, n.ID)
+	}
+	return ids, nil
+}
+
+// seed the random generator for Simulation.randomNode.
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+// randomUpNode returns a random SimNode that is up.
+// Arguments are NodeIDs for nodes that should not be returned.
+func (s *Simulation) randomUpNode(exclude ...discover.NodeID) *adapters.SimNode {
+	return s.randomNode(s.UpNodeIDs(), exclude...)
+}
+
+// randomUpNode returns a random SimNode that is not up.
+func (s *Simulation) randomDownNode(exclude ...discover.NodeID) *adapters.SimNode {
+	return s.randomNode(s.DownNodeIDs(), exclude...)
+}
+
+// randomUpNode returns a random SimNode from the slice of NodeIDs.
+func (s *Simulation) randomNode(ids []discover.NodeID, exclude ...discover.NodeID) *adapters.SimNode {
+	for _, e := range exclude {
+		var i int
+		for _, id := range ids {
+			if id == e {
+				ids = append(ids[:i], ids[i+1:]...)
+			} else {
+				i++
+			}
+		}
+	}
+	l := len(ids)
+	if l == 0 {
+		return nil
+	}
+	n := s.Net.GetNode(ids[rand.Intn(l)])
+	node, _ := n.Node.(*adapters.SimNode)
+	return node
+}