feat: move main task logic to runtime package

engine/engine.go

@@ -0,0 +1,43 @@
+package engine
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// Start start docker engine api loop
+func Start(ctx context.Context) error {
+	engine, err := New()
+	if err != nil {
+		return err
+	}
+
+	count := 0
+	for {
+		err := engine.Ping(ctx)
+		if err == context.Canceled {
+			break
+		}
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		default:
+		}
+		if err != nil {
+			log.WithError(err).
+				Errorln("cannot ping the docker daemon")
+			count++
+			if count == 5 {
+				return fmt.Errorf("retry connect to docker daemon failed: %d times", count)
+			}
+			time.Sleep(time.Second)
+		} else {
+			log.Infoln("successfully ping the docker daemon")
+			break
+		}
+	}
+	return nil
+}