Fix edge case for accessing accounts through rpc (#134)

* Add mutex and close keybase database correctly after use

* Add options http request to rpc API for remix

rpc/config.go

@@ -74,7 +74,7 @@ func registerRoutes(rs *lcd.RestServer) {
 		}
 	}
 
-	rs.Mux.HandleFunc("/rpc", s.ServeHTTP).Methods("POST")
+	rs.Mux.HandleFunc("/", s.ServeHTTP).Methods("POST", "OPTIONS")
 }
 
 func unlockKeyFromNameAndPassphrase(accountName, passphrase string) (emintKey emintcrypto.PrivKeySecp256k1, err error) {

rpc/eth_api.go

@@ -6,6 +6,7 @@ import (
 	"log"
 	"math/big"
 	"strconv"
+	"sync"
 
 	emintcrypto "github.com/cosmos/ethermint/crypto"
 	emintkeys "github.com/cosmos/ethermint/keys"
@@ -37,10 +38,11 @@ import (
 
 // PublicEthAPI is the eth_ prefixed set of APIs in the Web3 JSON-RPC spec.
 type PublicEthAPI struct {
-	cliCtx    context.CLIContext
-	key       emintcrypto.PrivKeySecp256k1
-	nonceLock *AddrLocker
-	gasLimit  *int64
+	cliCtx      context.CLIContext
+	key         emintcrypto.PrivKeySecp256k1
+	nonceLock   *AddrLocker
+	keybaseLock sync.Mutex
+	gasLimit    *int64
 }
 
 // NewPublicEthAPI creates an instance of the public ETH Web3 API.
@@ -103,6 +105,8 @@ func (e *PublicEthAPI) GasPrice() *hexutil.Big {
 
 // Accounts returns the list of accounts available to this node.
 func (e *PublicEthAPI) Accounts() ([]common.Address, error) {
+	e.keybaseLock.Lock()
+
 	addresses := make([]common.Address, 0) // return [] instead of nil if empty
 	keybase, err := emintkeys.NewKeyBaseFromHomeFlag()
 	if err != nil {
@@ -114,6 +118,9 @@ func (e *PublicEthAPI) Accounts() ([]common.Address, error) {
 		return addresses, err
 	}
 
+	keybase.CloseDB()
+	e.keybaseLock.Unlock()
+
 	for _, info := range infos {
 		addressBytes := info.GetPubKey().Address().Bytes()
 		addresses = append(addresses, common.BytesToAddress(addressBytes))

rpc/filters.go

@@ -17,7 +17,7 @@ type Filter struct {
 	addresses []common.Address
 	topics    [][]common.Hash
 
-	block      common.Hash // Block hash if filtering a single block
+	block common.Hash // Block hash if filtering a single block
 }
 
 // NewBlockFilter creates a new filter which directly inspects the contents of

rpc/tester/tester_test.go

@@ -27,7 +27,7 @@ const (
 	addrAStoreKey = 0
 )
 
-var addr = fmt.Sprintf("http://%s:%d/rpc", host, port)
+var addr = fmt.Sprintf("http://%s:%d", host, port)
 
 type Request struct {
 	Version string   `json:"jsonrpc"`