From 02ca71cfa92a1c3c8c573e64e209d254c5e3d5c6 Mon Sep 17 00:00:00 2001
From: i-norden <iansnorden@gmail.com>
Date: Thu, 30 Dec 2021 15:55:55 -0600
Subject: [PATCH] RPC server RPC utils

---
 pkg/rpc/http.go | 47 +++++++++++++++++++++++++
 pkg/rpc/ipc.go  | 91 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 138 insertions(+)
 create mode 100644 pkg/rpc/http.go
 create mode 100644 pkg/rpc/ipc.go

diff --git a/pkg/rpc/http.go b/pkg/rpc/http.go
new file mode 100644
index 0000000..41b5057
--- /dev/null
+++ b/pkg/rpc/http.go
@@ -0,0 +1,47 @@
+// VulcanizeDB
+// Copyright © 2022 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program 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 Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package rpc
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/cmd/utils"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/rpc"
+	log "github.com/sirupsen/logrus"
+)
+
+// StartHTTPEndpoint starts the HTTP RPC endpoint, configured with cors/vhosts/modules.
+func StartHTTPEndpoint(endpoint string, apis []rpc.API, modules []string, cors []string, vhosts []string, timeouts rpc.HTTPTimeouts) (*rpc.Server, error) {
+
+	srv := rpc.NewServer()
+	err := node.RegisterApis(apis, modules, srv, false)
+	if err != nil {
+		utils.Fatalf("Could not register HTTP API: %w", err)
+	}
+	handler := node.NewHTTPHandlerStack(srv, cors, vhosts)
+
+	// start http server
+	_, addr, err := node.StartHTTPEndpoint(endpoint, rpc.DefaultHTTPTimeouts, handler)
+	if err != nil {
+		utils.Fatalf("Could not start RPC api: %v", err)
+	}
+	extapiURL := fmt.Sprintf("http://%v/", addr)
+	log.Infof("HTTP endpoint opened %s", extapiURL)
+
+	return srv, err
+}
diff --git a/pkg/rpc/ipc.go b/pkg/rpc/ipc.go
new file mode 100644
index 0000000..146abde
--- /dev/null
+++ b/pkg/rpc/ipc.go
@@ -0,0 +1,91 @@
+// VulcanizeDB
+// Copyright © 2022 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program 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 Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package rpc
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"path/filepath"
+
+	"github.com/ethereum/go-ethereum/p2p/netutil"
+	"github.com/ethereum/go-ethereum/rpc"
+	log "github.com/sirupsen/logrus"
+	"github.com/vulcanize/ipld-eth-server/pkg/prom"
+)
+
+var (
+	//  On Linux, sun_path is 108 bytes in size
+	// see http://man7.org/linux/man-pages/man7/unix.7.html
+	maxPathSize = 108
+)
+
+// ipcListen will create a Unix socket on the given endpoint.
+func ipcListen(endpoint string) (net.Listener, error) {
+	if len(endpoint) > int(maxPathSize) {
+		log.Warn(fmt.Sprintf("The ipc endpoint is longer than %d characters. ", maxPathSize),
+			"endpoint", endpoint)
+	}
+
+	// Ensure the IPC path exists and remove any previous leftover
+	if err := os.MkdirAll(filepath.Dir(endpoint), 0751); err != nil {
+		return nil, err
+	}
+	os.Remove(endpoint)
+	l, err := net.Listen("unix", endpoint)
+	if err != nil {
+		return nil, err
+	}
+	os.Chmod(endpoint, 0600)
+	return l, nil
+}
+
+func ipcServe(srv *rpc.Server, listener net.Listener) {
+	for {
+		conn, err := listener.Accept()
+		if netutil.IsTemporaryError(err) {
+			log.WithError(err).Warn("rpc accept error")
+			continue
+		}
+		if err != nil {
+			log.WithError(err).Warn("unknown error")
+			continue
+		}
+		log.WithField("addr", conn.RemoteAddr()).Trace("accepted ipc connection")
+		go prom.IPCMiddleware(srv, conn)
+	}
+}
+
+// StartIPCEndpoint starts an IPC endpoint.
+func StartIPCEndpoint(ipcEndpoint string, apis []rpc.API) (net.Listener, *rpc.Server, error) {
+	// Register all the APIs exposed by the services.
+	handler := rpc.NewServer()
+	for _, api := range apis {
+		if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
+			return nil, nil, err
+		}
+		log.Debug("IPC registered", "namespace", api.Namespace)
+	}
+	// All APIs registered, start the IPC listener.
+	listener, err := ipcListen(ipcEndpoint)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	go ipcServe(handler, listener)
+	return listener, handler, nil
+}