Parity-ethereum: Dev mode times out on send transaction

[Pet3ris]

I'm running:

• Which Parity version?: latest docker image parity/parity
• Which operating system?: MacOS
• How installed?: docker
• Are you fully synchronized?: n/a
• Which network are you connected to?: dev
• Did you try to restart the node?: yes

How to reproduce

Running parity like so:

docker run -d -p 8545:8545 parity/parity --config dev --jsonrpc-interface all --jsonrpc-apis all --jsonrpc-cors "*"

I'm having trouble with transactions that never complete.

Web3.py (this code times out):

import web3
from web3 import HTTPProvider, Web3
w3 = Web3(HTTPProvider("http://localhost:8545"))
w3.eth.sendTransaction({'to': w3.eth.accounts[1], 'from': w3.eth.coinbase, 'value': 3 * 10**9})

Web3.js (this code hangs):

var Web3 = require('web3');
var web3 = new Web3(new Web3.providers.HttpProvider('http://localhost:8545'));
var BN = web3.utils.BN;

web3.eth.getAccounts(async (err, acc) => {
    let startingBalance = web3.utils.toBN(await web3.eth.getBalance(acc[0]))
    console.log(startingBalance.toString());
    let result = await web3.eth.sendTransaction({
        from: acc[0],
        to: acc[1],
        value: 1000000
    })
    console.log(result);
});

The same code works perfectly fine with geth --dev or ganache nodes.

[Tbaut]

You need to unlock the account you are using, pre-sign the transaction or use personal_sendTransaction. Web3 is waiting for you to sign it in this case.

[Pet3ris]

Thanks for the note @Tbaut . I've traced the same problem in this thread: https://github.com/paritytech/parity/issues/5335 which was apparently resolved by https://github.com/paritytech/parity/pull/5612. However despite what https://github.com/paritytech/parity/pull/5612 claims, accounts 0 and 1 are not unlocked by default. Was there developer documentation I've missed about how to use parity for integration testing?

[Tbaut]

The ticket mentioned creates an account, it's in ~/.local/share/io.parity.ethereum/keys/DevelopmentChain/ but there is no mention of unlock it.

[Pet3ris]

@Tbaut, in this StackOverflow thread I've found an explanation that suggests the "rich" account is the account recovered with an empty passphrase, however, this code reveals it to have 0 balance.

rich = web3.personal.newAccount("")
web3.personal.unlockAccount(rich, "")
print(w3.eth.getBalance(rich)) #=> 0

[Tbaut]

Check this out, it's the chain spec of the dev chain. This account is rich and it has already been created for you:
https://github.com/paritytech/parity/blob/master/ethcore/res/instant_seal.json#L49

[Pet3ris]

@Tbaut, thanks a lot, was able to confirm the address like so (it indeed has the balance as stated):

if client == 'parity':
    rich = to_checksum_address("00a329c0648769a73afac7f9381e08fb43dbea72")
    w3.personal.unlockAccount(rich, "")
else:
    rich = w3.eth.coinbase

However, the unlocked address is still unable to send transactions.

[Pet3ris]

@Tbaut sorted, I was able to send using `personal.sendTransaction' like so:

w3.personal.sendTransaction({'to': w3.eth.accounts[1], 'from': rich, 'value': 3*10**9}, "")

Thanks a lot for helping me out, will summarise the steps and feed back from all relevant tickets for future stumblers.

[Pet3ris]

Summary:

• Parity is a more secure node, so behaves differently in dev mode compared to geth or ganache
• It does offer a "coinbase" account with significant ether in address 00a329c0648769a73afac7f9381e08fb43dbea72 unlocked by the empty passphrase ""
• However, every account either needs to be unlocked or signed on transaction
• Moreover, unlocking is only active for one request, so signature is preferred
• A typical transaction like w3.eth.sendTransaction(tx) needs to change to w3.personal.sendTransaction(tx, passphrase)