Eth2 API: node endpoints outline (#7522)

* Nodev1 outline

* Gaz

Co-authored-by: Preston Van Loon <preston@prysmaticlabs.com>
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>

beacon-chain/rpc/nodev1/BUILD.bazel

@@ -0,0 +1,29 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_test")
+load("@prysm//tools/go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "node.go",
+        "server.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/beacon-chain/rpc/nodev1",
+    visibility = ["//beacon-chain:__subpackages__"],
+    deps = [
+        "//beacon-chain/blockchain:go_default_library",
+        "//beacon-chain/db:go_default_library",
+        "//beacon-chain/p2p:go_default_library",
+        "//beacon-chain/sync:go_default_library",
+        "@com_github_gogo_protobuf//types:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prysmaticlabs_ethereumapis//eth/v1:go_default_library",
+        "@org_golang_google_grpc//:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["server_test.go"],
+    embed = [":go_default_library"],
+    deps = ["@com_github_prysmaticlabs_ethereumapis//eth/v1:go_default_library"],
+)

beacon-chain/rpc/nodev1/node.go

@@ -0,0 +1,48 @@
+package nodev1
+
+import (
+	"context"
+
+	ptypes "github.com/gogo/protobuf/types"
+	"github.com/pkg/errors"
+	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1"
+)
+
+// GetIdentity retrieves data about the node's network presence.
+func (ns *Server) GetIdentity(ctx context.Context, _ *ptypes.Empty) (*ethpb.IdentityResponse, error) {
+	return nil, errors.New("unimplemented")
+}
+
+// GetPeer retrieves data about the given peer.
+func (ns *Server) GetPeer(ctx context.Context, req *ethpb.PeerRequest) (*ethpb.PeerResponse, error) {
+	return nil, errors.New("unimplemented")
+}
+
+// ListPeers retrieves data about the node's network peers.
+func (ns *Server) ListPeers(ctx context.Context, _ *ptypes.Empty) (*ethpb.PeersResponse, error) {
+	return nil, errors.New("unimplemented")
+}
+
+// GetVersion requests that the beacon node identify information about its implementation in a
+// format similar to a HTTP User-Agent field.
+func (ns *Server) GetVersion(ctx context.Context, _ *ptypes.Empty) (*ethpb.VersionResponse, error) {
+	return nil, errors.New("unimplemented")
+}
+
+// GetSyncStatus requests the beacon node to describe if it's currently syncing or not, and
+// if it is, what block it is up to.
+func (ns *Server) GetSyncStatus(ctx context.Context, _ *ptypes.Empty) (*ethpb.SyncingResponse, error) {
+	return nil, errors.New("unimplemented")
+}
+
+// GetHealth returns node health status in http status codes. Useful for load balancers.
+// Response Usage:
+//    "200":
+//      description: Node is ready
+//    "206":
+//      description: Node is syncing but can serve incomplete data
+//    "503":
+//      description: Node not initialized or having issues
+func (ns *Server) GetHealth(ctx context.Context, _ *ptypes.Empty) (*ptypes.Empty, error) {
+	return nil, errors.New("unimplemented")
+}

beacon-chain/rpc/nodev1/server.go

@@ -0,0 +1,25 @@
+// Package nodev1 defines a gRPC node service implementation, providing
+// useful endpoints for checking a node's sync status, peer info,
+// genesis data, and version information.
+package nodev1
+
+import (
+	"github.com/prysmaticlabs/prysm/beacon-chain/blockchain"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db"
+	"github.com/prysmaticlabs/prysm/beacon-chain/p2p"
+	"github.com/prysmaticlabs/prysm/beacon-chain/sync"
+	"google.golang.org/grpc"
+)
+
+// Server defines a server implementation of the gRPC Node service,
+// providing RPC endpoints for verifying a beacon node's sync status, genesis and
+// version information.
+type Server struct {
+	SyncChecker        sync.Checker
+	Server             *grpc.Server
+	BeaconDB           db.ReadOnlyDatabase
+	PeersFetcher       p2p.PeersProvider
+	PeerManager        p2p.PeerManager
+	GenesisTimeFetcher blockchain.TimeFetcher
+	GenesisFetcher     blockchain.GenesisFetcher
+}

beacon-chain/rpc/nodev1/server_test.go

@@ -0,0 +1,7 @@
+package nodev1
+
+import (
+	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1"
+)
+
+var _ ethpb.BeaconNodeServer = (*Server)(nil)