add flags to control gateway lookback parameters

cmd/lotus-gateway/main.go

@@ -8,6 +8,7 @@ import (
 
 	"contrib.go.opencensus.io/exporter/prometheus"
 	"github.com/filecoin-project/go-jsonrpc"
+	"github.com/filecoin-project/go-state-types/abi"
 	promclient "github.com/prometheus/client_golang/prometheus"
 	"go.opencensus.io/tag"
 
@@ -70,6 +71,16 @@ var runCmd = &cli.Command{
 			Name:  "api-max-req-size",
 			Usage: "maximum API request size accepted by the JSON RPC server",
 		},
+		&cli.DurationFlag{
+			Name:  "api-max-lookback",
+			Usage: "maximum duration allowable for tipset lookbacks",
+			Value: LookbackCap,
+		},
+		&cli.Int64Flag{
+			Name:  "api-wait-lookback-limit",
+			Usage: "maximum number of blocks to search back through for message inclusion",
+			Value: int64(StateWaitLookbackLimit),
+		},
 	},
 	Action: func(cctx *cli.Context) error {
 		log.Info("Starting lotus gateway")
@@ -107,7 +118,11 @@ var runCmd = &cli.Command{
 			mux.Handle(path, rpcServer)
 		}
 
-		ma := metrics.MetricedGatewayAPI(NewGatewayAPI(api))
+		lookbackCap := cctx.Duration("api-max-lookback")
+
+		waitLookback := abi.ChainEpoch(cctx.Int64("api-wait-lookback-limit"))
+
+		ma := metrics.MetricedGatewayAPI(newGatewayAPI(api, lookbackCap, waitLookback))
 
 		serveRpc("/rpc/v1", ma)
 		serveRpc("/rpc/v0", lapi.Wrap(new(v1api.FullNodeStruct), new(v0api.WrapperV1Full), ma))