support for leetcode-style interviews

.gitignore

@@ -34,4 +34,4 @@ config.yaml
 past/
 
 # Private interview template content
-frontend/src/util/templateContent.ts
+frontend/src/util/reactTemplateContent.ts

Dockerfile.runner

@@ -0,0 +1,26 @@
+# Build stage
+FROM golang:1.25-alpine AS build
+
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -o runner ./cmd/runner
+
+# Production stage
+FROM alpine:latest
+
+RUN apk --no-cache add ca-certificates docker-cli && \
+    ln -s /usr/bin/docker /usr/local/bin/docker
+
+WORKDIR /app
+
+COPY --from=build /app/runner .
+COPY --from=build /app/config ./config
+COPY --from=build /app/docker ./docker
+
+EXPOSE 0
+
+CMD ["./runner"]

cmd/runner/main.go

@@ -0,0 +1,145 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/redis/go-redis/v9"
+
+	"goderpad/config"
+	"goderpad/execution"
+	"goderpad/models"
+	"goderpad/redisclient"
+	"goderpad/services"
+)
+
+const runnerGroup = "runners"
+
+func runnerConsumerName() string {
+	hostname, _ := os.Hostname()
+	return "runner-" + hostname
+}
+
+func main() {
+	if err := config.Load("config/config.yml"); err != nil {
+		log.Fatalf("failed to load config: %v", err)
+	}
+
+	if err := redisclient.Init(); err != nil {
+		log.Fatalf("failed to connect to redis: %v", err)
+	}
+	defer redisclient.Close()
+
+	// Build sandbox Docker images before accepting jobs
+	if config.GetEnableCodeExecution() {
+		execution.BuildImages()
+	}
+
+	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer stop()
+
+	rdb := redisclient.GetClient()
+	consumer := runnerConsumerName()
+
+	// Create consumer group for the jobs stream
+	err := rdb.XGroupCreateMkStream(ctx, services.JobsStream, runnerGroup, "0").Err()
+	if err != nil && err.Error() != "BUSYGROUP Consumer Group name already exists" {
+		log.Printf("warning: could not create jobs consumer group: %v", err)
+	}
+
+	log.Printf("code runner started (consumer=%s), waiting for jobs...", consumer)
+
+	for {
+		select {
+		case <-ctx.Done():
+			log.Println("runner shutting down")
+			return
+		default:
+		}
+
+		streams, err := rdb.XReadGroup(ctx, &redis.XReadGroupArgs{
+			Group:    runnerGroup,
+			Consumer: consumer,
+			Streams:  []string{services.JobsStream, ">"},
+			Count:    1,
+			Block:    5 * time.Second,
+		}).Result()
+
+		if err != nil {
+			if err == redis.Nil || ctx.Err() != nil {
+				continue
+			}
+			log.Printf("error reading jobs stream: %v", err)
+			time.Sleep(1 * time.Second)
+			continue
+		}
+
+		for _, stream := range streams {
+			for _, msg := range stream.Messages {
+				processJob(ctx, rdb, msg)
+			}
+		}
+	}
+}
+
+func processJob(ctx context.Context, rdb *redis.Client, msg redis.XMessage) {
+	data, ok := msg.Values["data"].(string)
+	if !ok {
+		log.Printf("invalid job message: %s", msg.ID)
+		rdb.XAck(ctx, services.JobsStream, runnerGroup, msg.ID)
+		return
+	}
+
+	var job models.ExecuteJob
+	if err := json.Unmarshal([]byte(data), &job); err != nil {
+		log.Printf("failed to unmarshal job: %v", err)
+		rdb.XAck(ctx, services.JobsStream, runnerGroup, msg.ID)
+		return
+	}
+
+	log.Printf("executing job %s: %s for room %s", job.JobID, job.Language, job.RoomID)
+
+	result := models.ExecuteResult{
+		JobID:  job.JobID,
+		RoomID: job.RoomID,
+		UserID: job.UserID,
+	}
+
+	execResult, err := execution.RunCode(job.Language, job.Code)
+	if err != nil {
+		result.Stdout = ""
+		result.Stderr = err.Error()
+		result.Code = -1
+	} else {
+		result.Stdout = execResult.Stdout
+		result.Stderr = execResult.Stderr
+		result.Code = execResult.Code
+	}
+
+	// Publish result back to Redis
+	resultData, err := json.Marshal(result)
+	if err != nil {
+		log.Printf("failed to marshal result for job %s: %v", job.JobID, err)
+		rdb.XAck(ctx, services.JobsStream, runnerGroup, msg.ID)
+		return
+	}
+
+	if err := rdb.XAdd(ctx, &redis.XAddArgs{
+		Stream: services.ResultsStream,
+		MaxLen: 1000,
+		Approx: true,
+		Values: map[string]interface{}{
+			"data": string(resultData),
+		},
+	}).Err(); err != nil {
+		log.Printf("failed to publish result for job %s: %v", job.JobID, err)
+	}
+
+	rdb.XAck(ctx, services.JobsStream, runnerGroup, msg.ID)
+	log.Printf("completed job %s (exit code: %d)", job.JobID, result.Code)
+}

cmd/server/main.go

@@ -1,16 +1,21 @@
 package main
 
 import (
+	"context"
 	"log"
+	"os/signal"
 	"strconv"
+	"syscall"
 
 	"github.com/gin-contrib/cors"
 	"github.com/gin-gonic/gin"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 
 	"goderpad/config"
+	"goderpad/execution"
 	"goderpad/handlers"
 	"goderpad/metrics"
+	"goderpad/redisclient"
 	"goderpad/services"
 )
 
@@ -36,8 +41,10 @@ func main() {
 		})
 	})
 
+	r.POST("/execute", handlers.ExecuteHandler)
 	r.POST("/createRoom", handlers.CreateRoomHandler)
 	r.POST("/joinRoom", handlers.JoinRoomHandler)
+	r.POST("/switchLanguage", handlers.SwitchLanguageHandler)
 	r.GET("/getRoomName/:roomID", handlers.GetRoomNameHandler)
 	r.GET("/past/:roomID", handlers.GetDocumentSaveHandler)
 	r.GET("/validateKey", handlers.ValidateKeyHandler)
@@ -48,6 +55,19 @@ func main() {
 
 	go services.DeleteRoomSaves()
 
+	if config.GetEnableCodeExecution() {
+		go execution.BuildImages()
+
+		if err := redisclient.Init(); err != nil {
+			log.Fatalf("Failed to connect to Redis: %v", err)
+		}
+		defer redisclient.Close()
+
+		ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+		defer stop()
+		go services.StartResultListener(ctx)
+	}
+
 	r.Run(":" + config.GetPort())
 }
 

config/config.example.yml

@@ -1,6 +1,13 @@
 server:
   port: YOUR_PORT_HERE
   api_key: YOUR_API_KEY_HERE
+  enable_code_execution: false
+  docker_binary_path: ""  # leave empty to use "docker" from $PATH, or set full path e.g. /usr/local/bin/docker
   allowed_origins:
     - "http://localhost:7777"
-    - "http://localhost:5173"
+    - "http://localhost:5173"
+
+redis:
+  addr: "localhost:6379"
+  password: ""
+  db: 0

config/config.go

@@ -9,12 +9,21 @@ import (
 
 type Config struct {
 	Server ServerConfig `yaml:"server"`
+	Redis  RedisConfig  `yaml:"redis"`
+}
+
+type RedisConfig struct {
+	Addr     string `yaml:"addr"`
+	Password string `yaml:"password"`
+	DB       int    `yaml:"db"`
 }
 
 type ServerConfig struct {
-	Port           string   `yaml:"port"`
-	APIKey         string   `yaml:"api_key"`
-	AllowedOrigins []string `yaml:"allowed_origins"`
+	Port                  string   `yaml:"port"`
+	APIKey                string   `yaml:"api_key"`
+	AllowedOrigins        []string `yaml:"allowed_origins"`
+	EnableCodeExecution bool `yaml:"enable_code_execution"`
+	DockerBinaryPath      string   `yaml:"docker_binary_path"`
 }
 
 var AppConfig Config
@@ -45,3 +54,32 @@ func GetAPIKey() string {
 func GetAllowedOrigins() []string {
 	return AppConfig.Server.AllowedOrigins
 }
+
+func GetEnableCodeExecution() bool {
+	return AppConfig.Server.EnableCodeExecution
+}
+
+func GetRedisAddr() string {
+	if env := os.Getenv("REDIS_ADDR"); env != "" {
+		return env
+	}
+	if AppConfig.Redis.Addr != "" {
+		return AppConfig.Redis.Addr
+	}
+	return "localhost:6379"
+}
+
+func GetRedisPassword() string {
+	return AppConfig.Redis.Password
+}
+
+func GetRedisDB() int {
+	return AppConfig.Redis.DB
+}
+
+func GetDockerBinaryPath() string {
+	if AppConfig.Server.DockerBinaryPath != "" {
+		return AppConfig.Server.DockerBinaryPath
+	}
+	return "docker"
+}

docker-compose.dev.yml

@@ -1,14 +1,38 @@
 services:
+  goderpad-redis:
+    image: redis:7-alpine
+    container_name: goderpad-redis
+    ports:
+      - "6379:6379"
+    profiles:
+      - code-execution
+
   goderpad-backend:
     build:
       context: .
       dockerfile: Dockerfile.backend
     container_name: goderpad-backend
     ports:
       - "7778:7778"
+    environment:
+      - REDIS_ADDR=goderpad-redis:6379
     volumes:
       - ./past:/app/past
 
+  goderpad-runner:
+    build:
+      context: .
+      dockerfile: Dockerfile.runner
+    container_name: goderpad-runner
+    environment:
+      - REDIS_ADDR=goderpad-redis:6379
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+    depends_on:
+      - goderpad-redis
+    profiles:
+      - code-execution
+
   goderpad-frontend:
     build:
       context: ./frontend
@@ -24,7 +48,7 @@ services:
     environment:
       - VITE_API_URL=http://localhost:7778
       - VITE_WS_URL=ws://localhost:7778
-    
+
   goderpad-nginx:
     image: nginx:alpine
     volumes:

docker-compose.yml

@@ -1,12 +1,34 @@
 services:
+  goderpad-redis:
+    image: redis:7-alpine
+    container_name: goderpad-redis
+    profiles:
+      - code-execution
+
   goderpad-backend:
     build:
       context: .
       dockerfile: Dockerfile.backend
     container_name: goderpad-backend
+    environment:
+      - REDIS_ADDR=goderpad-redis:6379
     volumes:
       - ./past:/app/past
 
+  goderpad-runner:
+    build:
+      context: .
+      dockerfile: Dockerfile.runner
+    container_name: goderpad-runner
+    environment:
+      - REDIS_ADDR=goderpad-redis:6379
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+    depends_on:
+      - goderpad-redis
+    profiles:
+      - code-execution
+
   goderpad-nginx:
     build:
       context: .

docker/cpp.Dockerfile

@@ -0,0 +1,2 @@
+FROM alpine:3.20
+RUN apk add --no-cache g++

docker/java.Dockerfile

@@ -0,0 +1 @@
+FROM eclipse-temurin:21-jdk-alpine

docker/javascript.Dockerfile

@@ -0,0 +1 @@
+FROM node:20-alpine