p2p/simulations: add mocker functionality (#15207)

This commit adds mocker functionality to p2p/simulations. A
mocker allows to starting/stopping of nodes via the HTTP API.

1 files changed, 171 insertions, 0 deletions

diff --git a/p2p/simulations/mocker_test.go b/p2p/simulations/mocker_test.go
new file mode 100644
index 000000000..6b866fb74
--- /dev/null
+++ b/p2p/simulations/mocker_test.go
@@ -0,0 +1,171 @@
+// Copyright 2017 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 simulations simulates p2p networks.
+// A mokcer simulates starting and stopping real nodes in a network.
+package simulations
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/url"
+	"strconv"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/p2p/discover"
+)
+
+func TestMocker(t *testing.T) {
+	//start the simulation HTTP server
+	_, s := testHTTPServer(t)
+	defer s.Close()
+
+	//create a client
+	client := NewClient(s.URL)
+
+	//start the network
+	err := client.StartNetwork()
+	if err != nil {
+		t.Fatalf("Could not start test network: %s", err)
+	}
+	//stop the network to terminate
+	defer func() {
+		err = client.StopNetwork()
+		if err != nil {
+			t.Fatalf("Could not stop test network: %s", err)
+		}
+	}()
+
+	//get the list of available mocker types
+	resp, err := http.Get(s.URL + "/mocker")
+	if err != nil {
+		t.Fatalf("Could not get mocker list: %s", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		t.Fatalf("Invalid Status Code received, expected 200, got %d", resp.StatusCode)
+	}
+
+	//check the list is at least 1 in size
+	var mockerlist []string
+	err = json.NewDecoder(resp.Body).Decode(&mockerlist)
+	if err != nil {
+		t.Fatalf("Error decoding JSON mockerlist: %s", err)
+	}
+
+	if len(mockerlist) < 1 {
+		t.Fatalf("No mockers available")
+	}
+
+	nodeCount := 10
+	var wg sync.WaitGroup
+
+	events := make(chan *Event, 10)
+	var opts SubscribeOpts
+	sub, err := client.SubscribeNetwork(events, opts)
+	defer sub.Unsubscribe()
+	//wait until all nodes are started and connected
+	//store every node up event in a map (value is irrelevant, mimic Set datatype)
+	nodemap := make(map[discover.NodeID]bool)
+	wg.Add(1)
+	nodesComplete := false
+	connCount := 0
+	go func() {
+		for {
+			select {
+			case event := <-events:
+				//if the event is a node Up event only
+				if event.Node != nil && event.Node.Up == true {
+					//add the correspondent node ID to the map
+					nodemap[event.Node.Config.ID] = true
+					//this means all nodes got a nodeUp event, so we can continue the test
+					if len(nodemap) == nodeCount {
+						nodesComplete = true
+						//wait for 3s as the mocker will need time to connect the nodes
+						//time.Sleep( 3 *time.Second)
+					}
+				} else if event.Conn != nil && nodesComplete {
+					connCount += 1
+					if connCount == (nodeCount-1)*2 {
+						wg.Done()
+						return
+					}
+				}
+			case <-time.After(30 * time.Second):
+				wg.Done()
+				t.Fatalf("Timeout waiting for nodes being started up!")
+			}
+		}
+	}()
+
+	//take the last element of the mockerlist as the default mocker-type to ensure one is enabled
+	mockertype := mockerlist[len(mockerlist)-1]
+	//still, use hardcoded "probabilistic" one if available ;)
+	for _, m := range mockerlist {
+		if m == "probabilistic" {
+			mockertype = m
+			break
+		}
+	}
+	//start the mocker with nodeCount number of nodes
+	resp, err = http.PostForm(s.URL+"/mocker/start", url.Values{"mocker-type": {mockertype}, "node-count": {strconv.Itoa(nodeCount)}})
+	if err != nil {
+		t.Fatalf("Could not start mocker: %s", err)
+	}
+	if resp.StatusCode != 200 {
+		t.Fatalf("Invalid Status Code received for starting mocker, expected 200, got %d", resp.StatusCode)
+	}
+
+	wg.Wait()
+
+	//check there are nodeCount number of nodes in the network
+	nodes_info, err := client.GetNodes()
+	if err != nil {
+		t.Fatalf("Could not get nodes list: %s", err)
+	}
+
+	if len(nodes_info) != nodeCount {
+		t.Fatalf("Expected %d number of nodes, got: %d", nodeCount, len(nodes_info))
+	}
+
+	//stop the mocker
+	resp, err = http.Post(s.URL+"/mocker/stop", "", nil)
+	if err != nil {
+		t.Fatalf("Could not stop mocker: %s", err)
+	}
+	if resp.StatusCode != 200 {
+		t.Fatalf("Invalid Status Code received for stopping mocker, expected 200, got %d", resp.StatusCode)
+	}
+
+	//reset the network
+	_, err = http.Post(s.URL+"/reset", "", nil)
+	if err != nil {
+		t.Fatalf("Could not reset network: %s", err)
+	}
+
+	//now the number of nodes in the network should be zero
+	nodes_info, err = client.GetNodes()
+	if err != nil {
+		t.Fatalf("Could not get nodes list: %s", err)
+	}
+
+	if len(nodes_info) != 0 {
+		t.Fatalf("Expected empty list of nodes, got: %d", len(nodes_info))
+	}
+}