Add --stream-logs flag to run-errand command

This will use SCP to copy a specific log file
(/var/vcap/sys/log/ERRAND-NAME/errand.log) from the running errand
instances and print the new lines on a given interval (default: 30s).

In the case of multiple-instance errands, their outputs will be
interleaved when streaming.

The standard errand Stdout summary will be suppressed when streaming.

ai-assisted=yes

Author: selzoc

cmd/cmd.go

@@ -226,7 +226,8 @@ func (c Cmd) Execute() (cmdErr error) {
 	case *RunErrandOpts:
 		director, deployment := c.directorAndDeployment()
 		downloader := NewUIDownloader(director, deps.Time, deps.FS, deps.UI)
-		return NewRunErrandCmd(deployment, downloader, deps.UI).Run(*opts)
+		quietSCPRunner := boshssh.NewQuietSCPRunner(deps.CmdRunner, deps.FS, deps.Logger)
+		return NewRunErrandCmd(deployment, downloader, deps.UI, quietSCPRunner, deps.FS, deps.Logger).Run(*opts)
 
 	case *AttachDiskOpts:
 		return NewAttachDiskCmd(c.deployment()).Run(*opts)

cmd/factory.go

@@ -94,10 +94,11 @@ func (f Factory) New(args []string) (Cmd, error) {
 		return nil
 	}
 
-	boshOpts.SSH.GatewayFlags.UUIDGen = f.deps.UUIDGen  //nolint:staticcheck
-	boshOpts.SCP.GatewayFlags.UUIDGen = f.deps.UUIDGen  //nolint:staticcheck
-	boshOpts.Logs.GatewayFlags.UUIDGen = f.deps.UUIDGen //nolint:staticcheck
-	boshOpts.Pcap.GatewayFlags.UUIDGen = f.deps.UUIDGen //nolint:staticcheck
+	boshOpts.SSH.GatewayFlags.UUIDGen = f.deps.UUIDGen      //nolint:staticcheck
+	boshOpts.SCP.GatewayFlags.UUIDGen = f.deps.UUIDGen      //nolint:staticcheck
+	boshOpts.Logs.GatewayFlags.UUIDGen = f.deps.UUIDGen     //nolint:staticcheck
+	boshOpts.Pcap.GatewayFlags.UUIDGen = f.deps.UUIDGen     //nolint:staticcheck
+	boshOpts.RunErrand.GatewayFlags.UUIDGen = f.deps.UUIDGen //nolint:staticcheck
 
 	helpText := bytes.NewBufferString("")
 	parser.WriteHelp(helpText)

cmd/opts/opts.go

@@ -716,6 +716,10 @@ type RunErrandOpts struct {
 	DownloadLogs  bool        `long:"download-logs" description:"Download logs"`
 	LogsDirectory DirOrCWDArg `long:"logs-dir" description:"Destination directory for logs" default:"."`
 
+	StreamLogs *int `long:"stream-logs" description:"Stream errand logs (only /var/vcap/sys/log/ERRAND-NAME/errand.log) from the instance during execution. Optionally specify poll interval in seconds" optional:"true" optional-value:"30"`
+
+	GatewayFlags
+
 	cmd
 }