add script to run a local devnet, and helper command

cli/wait.go

@@ -0,0 +1,34 @@
+package cli
+
+import (
+	"fmt"
+	"time"
+
+	"gopkg.in/urfave/cli.v2"
+)
+
+var waitApiCmd = &cli.Command{
+	Name:  "wait-api",
+	Usage: "Wait for lotus api to come online",
+	Action: func(cctx *cli.Context) error {
+		for i := 0; i < 30; i++ {
+			api, closer, err := GetFullNodeAPI(cctx)
+			if err != nil {
+				fmt.Printf("Not online yet... (%s)\n", err)
+				time.Sleep(time.Second)
+				continue
+			}
+			defer closer()
+
+			ctx := ReqContext(cctx)
+
+			_, err = api.ID(ctx)
+			if err != nil {
+				return err
+			}
+
+			return nil
+		}
+		return fmt.Errorf("timed out waiting for api to come online")
+	},
+}