Add load test runner service

- embed rakyll/hey in the runner container image

cmd/loadtest/main.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"flag"
+	"github.com/knative/pkg/signals"
+	"github.com/stefanprodan/flagger/pkg/loadtest"
+	"github.com/stefanprodan/flagger/pkg/logging"
+	"log"
+	"time"
+)
+
+var (
+	logLevel string
+	port     string
+	timeout  time.Duration
+)
+
+func init() {
+	flag.StringVar(&logLevel, "log-level", "debug", "Log level can be: debug, info, warning, error.")
+	flag.StringVar(&port, "port", "9090", "Port to listen on.")
+	flag.DurationVar(&timeout, "timeout", time.Hour, "Command exec timeout.")
+}
+
+func main() {
+	flag.Parse()
+
+	logger, err := logging.NewLogger(logLevel)
+	if err != nil {
+		log.Fatalf("Error creating logger: %v", err)
+	}
+	defer logger.Sync()
+
+	stopCh := signals.SetupSignalHandler()
+
+	taskRunner := loadtest.NewTaskRunner(logger, timeout)
+
+	go taskRunner.Start(100*time.Millisecond, stopCh)
+
+	logger.Infof("Starting HTTP server on port %s", port)
+	loadtest.ListenAndServe(port, time.Minute, logger, taskRunner, stopCh)
+}