feat: add server log endpoint and streaming

local/service/docker_log_streamer.go

@@ -6,6 +6,7 @@ import (
 	"bufio"
 	"context"
 	"io"
+	"strconv"
 	"sync"
 
 	"github.com/docker/docker/api/types"
@@ -72,3 +73,34 @@ func (s *DockerLogStreamer) Stop(serverID uuid.UUID) {
 		v.(context.CancelFunc)()
 	}
 }
+
+func (s *DockerLogStreamer) GetLastLines(ctx context.Context, server *model.Server, n int) ([]string, error) {
+	if n <= 0 || server.ContainerID == "" {
+		return []string{}, nil
+	}
+
+	rc, err := s.client.ContainerLogs(ctx, server.ContainerID, types.ContainerLogsOptions{
+		ShowStdout: true,
+		ShowStderr: true,
+		Tail:       strconv.Itoa(n),
+	})
+	if err != nil {
+		return nil, err
+	}
+	defer rc.Close()
+
+	pr, pw := io.Pipe()
+	go func() {
+		defer pw.Close()
+		if _, err := stdcopy.StdCopy(pw, pw, rc); err != nil && err != io.EOF {
+			logging.Warn("DockerLogStreamer.GetLastLines: stdcopy error for %s: %v", server.ServiceName, err)
+		}
+	}()
+
+	var lines []string
+	scanner := bufio.NewScanner(pr)
+	for scanner.Scan() {
+		lines = append(lines, scanner.Text())
+	}
+	return lines, scanner.Err()
+}

local/service/file_log_streamer.go

@@ -3,7 +3,9 @@ package service
 import (
 	"acc-server-manager/local/model"
 	"acc-server-manager/local/utl/tracking"
+	"bufio"
 	"context"
+	"os"
 	"path/filepath"
 	"sync"
 
@@ -36,3 +38,31 @@ func (s *FileLogStreamer) Stop(serverID uuid.UUID) {
 		v.(*tracking.LogTailer).Stop()
 	}
 }
+
+func (s *FileLogStreamer) GetLastLines(_ context.Context, server *model.Server, n int) ([]string, error) {
+	if n <= 0 {
+		return []string{}, nil
+	}
+	logPath := filepath.Join(server.GetLogPath(), "server.log")
+	f, err := os.Open(logPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return []string{}, nil
+		}
+		return nil, err
+	}
+	defer f.Close()
+
+	var lines []string
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		lines = append(lines, scanner.Text())
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+	if len(lines) <= n {
+		return lines, nil
+	}
+	return lines[len(lines)-n:], nil
+}

local/service/server.go

@@ -47,12 +47,27 @@ type pendingState struct {
 
 func (s *ServerService) ensureLogTailing(server *model.Server, instance *tracking.AccServerInstance) {
 	go func() {
-		if err := s.logStreamer.Start(context.Background(), server, instance.HandleLogLine); err != nil {
+		handleFn := func(line string) {
+			instance.HandleLogLine(line)
+			s.webSocketService.BroadcastLogLine(server.ID, line)
+		}
+		if err := s.logStreamer.Start(context.Background(), server, handleFn); err != nil {
 			logging.Error("Failed to start log streaming for server %s: %v", server.ID, err)
 		}
 	}()
 }
 
+func (s *ServerService) GetLastLogLines(ctx *fiber.Ctx, serverID uuid.UUID, n int) ([]string, error) {
+	server, err := s.repository.GetByID(ctx.UserContext(), serverID)
+	if err != nil {
+		return nil, err
+	}
+	if n <= 0 {
+		n = 100
+	}
+	return s.logStreamer.GetLastLines(ctx.UserContext(), server, n)
+}
+
 func NewServerService(
 	repository *repository.ServerRepository,
 	stateHistoryRepo *repository.StateHistoryRepository,

local/service/websocket.go

@@ -103,6 +103,16 @@ func (ws *WebSocketService) BroadcastError(serverID uuid.UUID, error string, det
 	ws.broadcastToServer(serverID, wsMsg)
 }
 
+func (ws *WebSocketService) BroadcastLogLine(serverID uuid.UUID, line string) {
+	msg := model.WebSocketMessage{
+		Type:      model.MessageTypeLogLine,
+		ServerID:  &serverID,
+		Timestamp: time.Now().Unix(),
+		Data:      model.LogLineMessage{Line: line},
+	}
+	ws.broadcastToServer(serverID, msg)
+}
+
 func (ws *WebSocketService) BroadcastComplete(serverID uuid.UUID, success bool, message string) {
 	completeMsg := model.CompleteMessage{
 		ServerID: serverID,