Add a sample of Golang gRPC client/server programs

demos/golang/grpc_pingpong/.gitignore

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+occlum_ping
+occlum_pong
+occlum_ping_instance/
+occlum_pong_instance/
+go.sum
+github.com/

demos/golang/grpc_pingpong/README.md

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+# Use Golang and gRPC with Occlum
+
+This project demonstrates how Occlum enables [Golang](https://golang.org) programs with [gRPC](google.golang.org/grpc) calls running in SGX enclaves. The client program invokes a gRPC call with a ping message, and receives a pong message sent by the server program.
+
+Step 1: Build the Golang gRPC application using the Occlum Golang toolchain via
+```
+./prepare_ping_pong.sh
+```
+
+Step 2: Run the gRPC server demo on Occlum via
+```
+./run_pong_on_occlum.sh
+```
+The gRPC server should now start to listen on port 8888 and serve incoming requests.
+
+Step 3: Run the gRPC client demo on Occlum via
+```
+./run_ping_on_occlum.sh
+```
+After the reply message is received, the latency incurred during a gRPC call will be printed out.

demos/golang/grpc_pingpong/go.mod

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+module grpc_pingpong
+
+go 1.13
+
+require (
+	github.com/golang/protobuf v1.4.1
+	google.golang.org/grpc v1.33.0-dev
+	google.golang.org/protobuf v1.25.0
+)

demos/golang/grpc_pingpong/ping.go

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+package main
+
+import (
+	"fmt"
+	"time"
+
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+
+	"grpc_pingpong/github.com/occlum/demos/grpc_pingpong/pingpong"
+)
+
+func main() {
+	conn, err := grpc.Dial("localhost:8888", grpc.WithInsecure())
+	if err != nil {
+		fmt.Printf("Failed to connect: %s\n", err)
+	}
+	defer conn.Close()
+
+	previousTime := time.Now()
+	fmt.Printf("Ping: at %s\n", previousTime.Format("2006-01-02T15:04:05.999999999Z07:00"))
+	client := pingpong.NewPingPongServiceClient(conn)
+	response, err := client.PingPong(context.Background(), &pingpong.PingPongMesg{Ping: "Hello"})
+	if err != nil {
+		fmt.Printf("Error when calling PingPongHandler: %s\n", err)
+	}
+	fmt.Printf("Pong from server: %s (at %s)\n", response.Pong, response.Timestamp)
+	currentTime := time.Now()
+	fmt.Printf("End-to-End latency is: %f Seconds\n", currentTime.Sub(previousTime).Seconds())
+}
+

demos/golang/grpc_pingpong/pingpong/pingpong.proto

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+syntax = "proto3";
+package pingpong;
+option go_package = "github.com/occlum/demos/grpc_pingpong/pingpong";
+
+message PingPongMesg {
+  string ping = 1;
+  string pong = 2;
+  string timestamp = 3;
+}
+
+service PingPongService {
+  rpc PingPong(PingPongMesg) returns (PingPongMesg) {}
+}

demos/golang/grpc_pingpong/pong.go

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+package main
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"time"
+
+	"google.golang.org/grpc"
+
+	"grpc_pingpong/github.com/occlum/demos/grpc_pingpong/pingpong"
+)
+
+func PingPong(ctx context.Context, in *pingpong.PingPongMesg) (*pingpong.PingPongMesg, error) {
+	currentTime := time.Now()
+	fmt.Printf("Receiving Ping: %s (at %s)\n", in.Ping, currentTime.Format("2006-01-02T15:04:05.999999999Z07:00"))
+	return &pingpong.PingPongMesg{Ping: in.Ping,
+				      Pong: fmt.Sprintf("Greetings from Pong! Ping Echoed: %s", in.Ping),
+				      Timestamp: currentTime.Format("2006-01-02T15:04:05.999999999Z07:00")}, nil
+			      }
+
+func main() {
+	fmt.Println("grpc_pingpong server is waiting for service requests ...")
+
+	conn, err := net.Listen("tcp", "localhost:8888")
+	if err != nil {
+		fmt.Printf("Failed to listen: %v\n", err)
+	}
+
+	grpcServer := grpc.NewServer()
+
+	pingpong.RegisterPingPongServiceService(grpcServer, &pingpong.PingPongServiceService{PingPong: PingPong})
+
+	if err := grpcServer.Serve(conn); err != nil {
+		fmt.Printf("Failed to serve: %s\n", err)
+	}
+}
+

demos/golang/grpc_pingpong/prepare_ping_pong.sh

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+#!/bin/bash
+set -e
+
+BLUE='\033[1;34m'
+NC='\033[0m'
+
+# sanity check
+FILE_SET="
+occlum_ping
+occlum_pong
+go.sum"
+for CURR_FILE in $FILE_SET
+do
+        if [ -f "$CURR_FILE" ]; then
+                rm $CURR_FILE
+        fi
+done
+
+DIR_SET="
+github.com
+occlum_ping_instance
+occlum_pong_instance"
+for CURR_DIR in $DIR_SET
+do
+        if [ -d "$CURR_DIR" ]; then
+                rm -fr $CURR_DIR
+        fi
+done
+
+# enable Go modules for package management 
+export GO111MODULE=on
+
+# update PATH so that the protoc compiler can find the plugin:
+export PATH="$PATH:$(go env GOPATH)/bin"
+
+# assume that protoc is installed
+if ! type "protoc" > /dev/null 2>&1; then
+        echo "Please install protoc"
+        exit 1
+fi
+
+# install protoc-gen-go and protoc-gen-go-grpc plugin
+if ! type "protoc-gen-go" > /dev/null 2>&1; then
+        go get google.golang.org/protobuf/cmd/protoc-gen-go
+fi
+if ! type "protoc-gen-go-grpc" > /dev/null 2>&1; then
+        go get google.golang.org/grpc/cmd/protoc-gen-go-grpc
+fi
+
+# compiling pingpong gRPC .proto file
+export GOPRIVATE=github.com/occlum/demos/\*
+protoc --proto_path=pingpong --go-grpc_out=. --go_out=. pingpong/pingpong.proto
+
+# prepare occlum images
+occlum-go build -o occlum_pong pong.go
+occlum-go build -o occlum_ping ping.go

demos/golang/grpc_pingpong/run_ping_on_occlum.sh

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+#!/bin/bash
+set -e
+
+BLUE='\033[1;34m'
+NC='\033[0m'
+
+occlum_ping="./occlum_ping"
+
+if [ ! -f $occlum_ping ];then
+    echo "Error: cannot stat file '$occlum_ping'"
+    echo "Please see README and build it using prepare_ping_pong.sh"
+    exit 1
+fi
+
+# Init Occlum Workspace
+rm -rf occlum_ping_instance && mkdir occlum_ping_instance
+cd occlum_ping_instance
+occlum init
+new_json="$(jq '.resource_limits.user_space_size = "2560MB" |
+	.resource_limits.kernel_space_heap_size="320MB" |
+	.resource_limits.kernel_space_stack_size="10MB" |
+	.process.default_stack_size = "40MB" |
+	.process.default_heap_size = "320MB" |
+	.process.default_mmap_size = "960MB" ' Occlum.json)" && \
+echo "${new_json}" > Occlum.json
+
+# 2. Copy program into Occlum Workspace and build
+cp ../occlum_ping image/bin
+mkdir image/etc/
+cp /etc/hosts image/etc/
+occlum build
+
+# 3. Run the hello world sample
+echo -e "${BLUE}occlum run /bin/occlum_ping${NC}"
+time occlum run /bin/occlum_ping

demos/golang/grpc_pingpong/run_pong_on_occlum.sh

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+#!/bin/bash
+set -e
+
+BLUE='\033[1;34m'
+NC='\033[0m'
+
+occlum_pong="./occlum_pong"
+
+if [ ! -f $occlum_pong ];then
+    echo "Error: cannot stat file '$occlum_pong'"
+    echo "Please see README and build it using prepare_pong_pong.sh"
+    exit 1
+fi
+
+# Init Occlum Workspace
+rm -rf occlum_pong_instance && mkdir occlum_pong_instance
+cd occlum_pong_instance
+occlum init
+new_json="$(jq '.resource_limits.user_space_size = "2560MB" |
+	.resource_limits.kernel_space_heap_size="320MB" |
+	.resource_limits.kernel_space_stack_size="10MB" |
+	.process.default_stack_size = "40MB" |
+	.process.default_heap_size = "320MB" |
+	.process.default_mmap_size = "960MB" ' Occlum.json)" && \
+echo "${new_json}" > Occlum.json
+
+# 2. Copy program into Occlum Workspace and build
+cp ../occlum_pong image/bin
+mkdir image/etc/
+cp /etc/hosts image/etc/
+occlum build
+
+# 3. Run the hello world sample
+echo -e "${BLUE}occlum run /bin/occlum_pong${NC}"
+time occlum run /bin/occlum_pong