Load testing: synthetic VMs, multiple worker support and Grafana k6 test (#389)

* Load testing: synthetic VMs, multiple worker support and Grafana k6 test

* echoserver: prevent fallthrough when Accept() fails

* Move default local-dev context logic to CreateDevController()

* Synthetic: add a random delay to startup script echoing

internal/controller/controller.go

@@ -66,6 +66,7 @@ type Controller struct {
 	disableDBCompression bool
 	pingInterval         time.Duration
 	prometheusMetrics    bool
+	synthetic            bool
 
 	sshListenAddr   string
 	sshSigner       ssh.Signer