1  package system
 2  
 3  import (
 4  	"bufio"
 5  	"context"
 6  	"io"
 7  	"log"
 8  	"os"
 9  	"path/filepath"
10  	"time"
11  
12  	dogeboxd "github.com/dogeorg/dogeboxd/pkg"
13  )
14  
15  func NewLogTailer(config dogeboxd.ServerConfig) LogTailer {
16  	return LogTailer{
17  		config: config,
18  	}
19  }
20  
21  type LogTailer struct {
22  	config dogeboxd.ServerConfig
23  }
24  
25  func (t LogTailer) GetChan(pupId string) (context.CancelFunc, chan string, error) {
26  	ctx, cancel := context.WithCancel(context.Background())
27  
28  	out := make(chan string, 10)
29  
30  	go func() {
31  		file, err := os.Open(filepath.Join(t.config.ContainerLogDir, "pup-"+pupId))
32  		if err != nil {
33  			close(out)
34  			log.Printf("Error opening log file: %+v", err)
35  			return
36  		}
37  		defer file.Close()
38  
39  		log.Printf("Opened log file: %s", file.Name())
40  
41  		// Seek to the end of the file
42  		_, err = file.Seek(0, io.SeekEnd)
43  		if err != nil {
44  			close(out)
45  			return
46  		}
47  
48  		reader := bufio.NewReader(file)
49  
50  		for {
51  			select {
52  			case <-ctx.Done():
53  				close(out)
54  				return
55  			default:
56  				line, err := reader.ReadString('\n')
57  				if err != nil {
58  					if err == io.EOF {
59  						time.Sleep(100 * time.Millisecond)
60  						continue
61  					}
62  					close(out)
63  					return
64  				}
65  				out <- line
66  			}
67  		}
68  
69  	}()
70  	return cancel, out, nil
71  }