New p2p package (#3196)

beacon-chain/p2p/BUILD.bazel

@@ -0,0 +1,31 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "config.go",
+        "doc.go",
+        "log.go",
+        "service.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/beacon-chain/p2p",
+    visibility = ["//beacon-chain:__subpackages__"],
+    deps = [
+        "//shared:go_default_library",
+        "@com_github_libp2p_go_libp2p//:go_default_library",
+        "@com_github_libp2p_go_libp2p_core//host:go_default_library",
+        "@com_github_libp2p_go_libp2p_pubsub//:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["service_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//shared/testutil:go_default_library",
+        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
+    ],
+)

beacon-chain/p2p/config.go

@@ -0,0 +1,16 @@
+package p2p
+
+// Config for the p2p service. These parameters are set from application level flags
+// to initialize the p2p service.
+type Config struct {
+	NoDiscovery       bool
+	StaticPeers       []string
+	BootstrapNodeAddr string
+	RelayNodeAddr     string
+	HostAddress       string
+	PrivateKey        string
+	Port              uint
+	MaxPeers          uint
+	WhitelistCIDR     string
+	EnableUPnP        bool
+}

beacon-chain/p2p/doc.go

@@ -0,0 +1,11 @@
+/*
+Package p2p implements the Ethereum 2.0 networking specification.
+
+Canonical spec reference: https://github.com/ethereum/eth2.0-specs/blob/dev/specs/networking/p2p-interface.md
+
+Prysm specific implementation design docs
+  - Networking Design Doc: https://docs.google.com/document/d/1VyhobQRkEjEkEPxmmdWvaHfKWn0j6dEae_wLZlrFtfU/view
+
+This package is heavily utilizes the libp2p go implementation by Protocol Labs.
+*/
+package p2p

beacon-chain/p2p/log.go

@@ -0,0 +1,5 @@
+package p2p
+
+import "github.com/sirupsen/logrus"
+
+var log = logrus.WithField("prefix", "p2p")

beacon-chain/p2p/service.go

@@ -0,0 +1,77 @@
+package p2p
+
+import (
+	"context"
+
+	"github.com/libp2p/go-libp2p"
+	"github.com/libp2p/go-libp2p-core/host"
+	pubsub "github.com/libp2p/go-libp2p-pubsub"
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/shared"
+)
+
+var _ = shared.Service(&Service{})
+
+// Service for managing peer to peer (p2p) networking.
+type Service struct {
+	ctx    context.Context
+	cancel context.CancelFunc
+
+	started    bool
+	cfg        *Config
+	startupErr error
+
+	host   host.Host
+	pubsub *pubsub.PubSub
+}
+
+// NewService initializes a new p2p service compatible with shared.Service interface. No
+// connections are made until the Start function is called during the service registry startup.
+func NewService(cfg *Config) (*Service, error) {
+	ctx, cancel := context.WithCancel(context.Background())
+	return &Service{
+		ctx:    ctx,
+		cancel: cancel,
+		cfg:    cfg,
+	}, nil
+}
+
+// Start the p2p service.
+func (s *Service) Start() {
+	if s.started {
+		log.Error("Attempted to start p2p service when it was already started")
+		return
+	}
+	s.started = true
+
+	// TODO(3147): Add host options
+	h, err := libp2p.New(s.ctx)
+	if err != nil {
+		s.startupErr = err
+		return
+	}
+	s.host = h
+
+	// TODO(3147): Add gossip sub options
+	gs, err := pubsub.NewGossipSub(s.ctx, s.host)
+	if err != nil {
+		s.startupErr = err
+		return
+	}
+	s.pubsub = gs
+}
+
+// Stop the p2p service and terminate all peer connections.
+func (s *Service) Stop() error {
+	s.started = false
+	return nil
+}
+
+// Status of the p2p service. Will return an error if the service is considered unhealthy to
+// indicate that this node should not serve traffic until the issue has been resolved.
+func (s *Service) Status() error {
+	if !s.started {
+		return errors.New("not running")
+	}
+	return nil
+}

beacon-chain/p2p/service_test.go

@@ -0,0 +1,37 @@
+package p2p
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/shared/testutil"
+	logTest "github.com/sirupsen/logrus/hooks/test"
+)
+
+func TestService_Stop_SetsStartedToFalse(t *testing.T) {
+	s, _ := NewService(nil)
+	s.started = true
+	_ = s.Stop()
+	if s.started != false {
+		t.Error("Expected Service.started to be false, got true")
+	}
+}
+
+func TestService_Start_OnlyStartsOnce(t *testing.T) {
+	hook := logTest.NewGlobal()
+
+	s, _ := NewService(nil)
+	defer s.Stop()
+	s.Start()
+	if s.started != true {
+		t.Error("Expected service to be started")
+	}
+	s.Start()
+	testutil.AssertLogsContain(t, hook, "Attempted to start p2p service when it was already started")
+}
+
+func TestService_Status_NotRunning(t *testing.T) {
+	s := &Service{started: false}
+	if s.Status().Error() != "not running" {
+		t.Errorf("Status returned wrong error, got %v", s.Status())
+	}
+}