Add baseFeePerGas to headers sent via EthSubscribe (#2060)

* mycelo: enable websockets

Makes it easier to test websocket specific operations (e.g.
subscriptions) and I don't see a reason not to turn in on.

* Add baseFeePerGas to headers via EthSubscribe

Closes celo-org/celo-blockchain-planning#59

Author: karlb

accounts/abi/bind/backends/simulated.go

@@ -874,6 +874,10 @@ func (fb *filterBackend) ServiceFilter(ctx context.Context, ms *bloombits.Matche
 	panic("not supported")
 }
 
+func (fb *filterBackend) RealGasPriceMinimumForHeader(ctx context.Context, currencyAddress *common.Address, header *types.Header) (*big.Int, error) {
+	return nil, fmt.Errorf("filterBackend does not implement RealGasPriceMinimumForHeader")
+}
+
 func nullSubscription() event.Subscription {
 	return event.NewSubscription(func(quit <-chan struct{}) error {
 		<-quit

eth/filters/api.go

@@ -30,6 +30,8 @@ import (
 	"github.com/celo-org/celo-blockchain/common/hexutil"
 	"github.com/celo-org/celo-blockchain/core/types"
 	"github.com/celo-org/celo-blockchain/ethdb"
+	"github.com/celo-org/celo-blockchain/internal/ethapi"
+	"github.com/celo-org/celo-blockchain/log"
 	"github.com/celo-org/celo-blockchain/rpc"
 )
 
@@ -223,7 +225,14 @@ func (api *PublicFilterAPI) NewHeads(ctx context.Context) (*rpc.Subscription, er
 		for {
 			select {
 			case h := <-headers:
-				notifier.Notify(rpcSub.ID, h)
+				jsonHeader := ethapi.RPCMarshalHeader(h)
+				baseFee, err := api.backend.RealGasPriceMinimumForHeader(ctx, nil, h)
+				if err != nil {
+					log.Debug("Not adding baseFeePerGas to header subscription, failed to retrieve gas price minimum", "block", h.Number.Uint64(), "err", err)
+				} else {
+					jsonHeader["baseFeePerGas"] = (*hexutil.Big)(baseFee)
+				}
+				notifier.Notify(rpcSub.ID, jsonHeader)
 			case <-rpcSub.Err():
 				headersSub.Unsubscribe()
 				return

eth/filters/filter.go

@@ -45,6 +45,7 @@ type Backend interface {
 
 	BloomStatus() (uint64, uint64)
 	ServiceFilter(ctx context.Context, session *bloombits.MatcherSession)
+	RealGasPriceMinimumForHeader(ctx context.Context, currencyAddress *common.Address, header *types.Header) (*big.Int, error)
 }
 
 // Filter can be used to retrieve and filter logs.

eth/filters/filter_system_test.go

@@ -156,6 +156,10 @@ func (b *testBackend) ServiceFilter(ctx context.Context, session *bloombits.Matc
 	}()
 }
 
+func (b *testBackend) RealGasPriceMinimumForHeader(ctx context.Context, currencyAddress *common.Address, header *types.Header) (*big.Int, error) {
+	return nil, fmt.Errorf("testBackend does not implement RealGasPriceMinimumForHeader")
+}
+
 // TestBlockSubscription tests if a block subscription returns block hashes for posted chain events.
 // It creates multiple subscriptions:
 // - one at the start and should receive all posted chain events and a second (blockHashes)

mycelo/cluster/node.go

@@ -40,6 +40,11 @@ func (nc *NodeConfig) RPCPort() int64 {
 	return int64(8545 + nc.Number)
 }
 
+// RPCPort is the rpc port this node will use
+func (nc *NodeConfig) WebsocketPort() int64 {
+	return int64(9545 + nc.Number)
+}
+
 // NodePort is the node port this node will use
 func (nc *NodeConfig) NodePort() int64 {
 	return int64(30303 + nc.Number)
@@ -165,6 +170,10 @@ func (n *Node) Run(ctx context.Context) error {
 		"--http.addr", "127.0.0.1",
 		"--http.port", strconv.FormatInt(n.RPCPort(), 10),
 		"--http.api", "eth,net,web3,debug,admin,personal,istanbul,txpool",
+		"--ws",
+		"--ws.addr", "127.0.0.1",
+		"--ws.port", strconv.FormatInt(n.WebsocketPort(), 10),
+		"--ws.api", "eth,net,web3,debug,admin,personal,istanbul,txpool",
 		// "--nodiscover", "--nousb ",
 		"--unlock", addressToUnlock,
 		"--password", n.pwdFile(),