Use websocket to transmit logs

app.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/docker/docker/pkg/stdcopy"
 	"github.com/gin-gonic/gin"
+	"nhooyr.io/websocket"
 
 	"github.com/nemunaire/minifaas/engine/docker"
 	"github.com/nemunaire/minifaas/ui"
@@ -41,7 +42,7 @@ func NewApp() App {
 	})
 
 	router.GET("/api/run", func(c *gin.Context) {
-		ctrid, err := docker.Run("hello-world")
+		ctrid, err := docker.Run("alpine", []string{"sh", "-c", "for i in `seq 20`; do echo $i; sleep 0.5; done"})
 		if err != nil {
 			c.JSON(http.StatusInternalServerError, gin.H{"error": err})
 		}
@@ -49,15 +50,39 @@ func NewApp() App {
 	})
 
 	router.GET("/api/jobs/:jobid/logs", func(c *gin.Context) {
+		ws, err := websocket.Accept(c.Writer, c.Request, nil)
+		if err != nil {
+			log.Fatal("error get connection", err)
+		}
+		defer ws.Close(websocket.StatusInternalError, "the sky is falling")
+
 		stream, err := docker.Logs(c.Param("jobid"))
 		if err != nil {
-			c.JSON(http.StatusInternalServerError, gin.H{"error": err})
+			log.Fatal("Unable to get log stream:", err)
 		}
 
-		_, err = stdcopy.StdCopy(c.Writer, c.Writer, stream)
+		r, w := io.Pipe()
+
+		ctx, cancel := context.WithTimeout(c.Request.Context(), time.Second*10)
+		defer cancel()
+
+		go func(reader io.Reader) {
+			buf := make([]byte, 128)
+			for {
+				n, err := reader.Read(buf)
+				if err != nil {
+					break
+				}
+				ws.Write(ctx, websocket.MessageText, buf[:n])
+			}
+		}(r)
+
+		_, err = stdcopy.StdCopy(w, w, stream)
 		if err != nil && err != io.EOF {
-			c.JSON(http.StatusInternalServerError, gin.H{"error": err})
+			log.Fatal("Something goes wrong during stream:", err)
 		}
+
+		ws.Close(websocket.StatusNormalClosure, "")
 	})
 
 	app := App{