JSON-RPC server

Looking for the list of supported RPC endpoints?

See the full checklist here: #835

Original Issue

We need to implement the basic API for JSON-RPC server. A simplistic start can be found here: https://github.com/ethereum/py-evm/tree/master/evm/rpc

Lets flesh this out further to something more complete. For now lets keep it as something that must be run as python evm/rpc/server.py ....

I suggest sticking to the read-only apis for now.

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Compiled to-do list:

(Checked off at the time of merge)

• support all the eth_* read-only methods
  • eth_protocolVersion
  • eth_syncing
  • eth_coinbase
  • eth_mining
  • eth_hashrate
  • eth_gasPrice
  • eth_accounts
  • eth_blockNumber
  • eth_getBalance
  • eth_getStorageAt
  • eth_getTransactionCount
  • eth_getBlockTransactionCountByHash
  • eth_getBlockTransactionCountByNumber
  • eth_getUncleCountByBlockHash
  • eth_getUncleCountByBlockNumber block int
  • eth_getUncleCountByBlockNumber block string
  • eth_getCode
  • eth_call
  • eth_estimateGas
  • eth_getBlockByHash
  • eth_getBlockByNumber block int
  • eth_getBlockByNumber block string
  • eth_getTransactionByHash
  • eth_getTransactionByBlockHashAndIndex
  • eth_getTransactionByBlockNumberAndIndex
  • eth_getTransactionReceipt
  • eth_getUncleByBlockHashAndIndex
  • eth_getUncleByBlockNumberAndIndex block int
  • eth_getUncleByBlockNumberAndIndex block string
  • eth_getCompilers
  • eth_getLogs
  • eth_getWork
• serve over socket
• make score available on block object, so that a returned block dict can be formatted without a chain reference ?

To save for another PR:

• server over HTTP

[pipermerriam]

Quick information drop about eth_estimateGas.

This may be as simple as returning computation.gas_meter.start_gas - computation.gas_meter.gas_remaining. However, if memory serves, I think it’s more complicated that that.

The way that I recall go-ethereum doing this is to execute the transaction with some very large upper bound of gas like 50,000,000.

• if it errors out: return an error over RPC
• if it passes, proceed into a binary search, re-running the transaction at each gas value until you find the spot where it succeeds/fails and use the success value.

I’ll re-iterate that the binary search approach may not be necessary based on how we do gas consumption tracking. Let’s see.

[pipermerriam]

Future TODO: make gas price strategy for eth_gasPrice pluggable and implement the Eth Gas Station strategy: https://github.com/ethereum/web3.py/issues/496