feat(lotus-sim): add an info command

cmd/lotus-sim/main.go

@@ -16,6 +16,7 @@ var root []*cli.Command = []*cli.Command{
 	deleteSimCommand,
 	listSimCommand,
 	runSimCommand,
+	infoSimCommand,
 	upgradeCommand,
 }
 

cmd/lotus-sim/simulation/simulation.go

@@ -143,6 +143,10 @@ func (sim *Simulation) GetHead() *types.TipSet {
 	return sim.head
 }
 
+func (sim *Simulation) GetNetworkVersion() network.Version {
+	return sim.sm.GetNtwkVersion(context.TODO(), sim.head.Height())
+}
+
 func (sim *Simulation) SetHead(head *types.TipSet) error {
 	if err := sim.MetadataDS.Put(sim.key("head"), head.Key().Bytes()); err != nil {
 		return xerrors.Errorf("failed to store simulation head: %w", err)

cmd/lotus-sim/stat.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"fmt"
+	"text/tabwriter"
+
+	"github.com/urfave/cli/v2"
+)
+
+var infoSimCommand = &cli.Command{
+	Name:        "info",
+	Description: "Output information about the simulation.",
+	Action: func(cctx *cli.Context) error {
+		node, err := open(cctx)
+		if err != nil {
+			return err
+		}
+		defer node.Close()
+
+		sim, err := node.LoadSim(cctx.Context, cctx.String("simulation"))
+		if err != nil {
+			return err
+		}
+		tw := tabwriter.NewWriter(cctx.App.Writer, 8, 8, 0, ' ', 0)
+		fmt.Fprintln(tw, "Name:\t", sim.Name())
+		fmt.Fprintln(tw, "Height:\t", sim.GetHead().Height())
+		fmt.Fprintln(tw, "TipSet:\t", sim.GetHead())
+		fmt.Fprintln(tw, "Network Version:\t", sim.GetNetworkVersion())
+		return tw.Flush()
+	},
+}