3.3.2. Sending Transactions With Python library

Open a new terminal (note that Iroha container and irohad should be up and running) and attach to an iroha docker container:

docker exec -it iroha /bin/bash

Now you are in the interactive shell of Iroha’s container.

3.3.2.1. Prerequisites

Note

The library only works in Python 3 environment (Python 2 is not supported).

To use Iroha Python library, you need to get it from the repository or via pip3:

pip3 install iroha

3.3.2.2. Creating your own key pairs with Python library

For testing purposes, you can use example keys. But you can also create your own. To create native Iroha ed25519 SHA-3 keys (difference between algorithms can be found here), please use the following code:

from iroha import IrohaCrypto

# these first two lines are enough to create the keys
private_key = IrohaCrypto.private_key()
public_key = IrohaCrypto.derive_public_key(private_key)

# the rest of the code writes them into the file
with open('keypair.priv', 'wb') as f:
    f.write(private_key)

with open('keypair.pub', 'wb') as f:
    f.write(public_key)

And for HL Ursa ed25519 SHA-2 keys in Multihash format, please use:

from iroha import IrohaCrypto, ed25519_sha2
from nacl.encoding import HexEncoder

private_key = ed25519_sha2.SigningKey.generate()
public_key = IrohaCrypto.derive_public_key(private_key).encode('ascii')

with open('keypair.priv', 'wb') as f:
    f.write(private_key.encode(encoder=HexEncoder))
    f.write(public_key[6:])

with open('keypair.pub', 'wb') as f:
    f.write(public_key)

Now, as we have the library and the keys, we can start sending the actual transactions.

3.3.2.3. Running example transactions

If you only want to try what Iroha transactions would look like, you can simply go to the examples from the repository here. Here is the tx-example.py file with comments to clarify each step:

#!/usr/bin/env python3
#
# Copyright Soramitsu Co., Ltd. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
#

import os
import binascii
from iroha import IrohaCrypto
from iroha import Iroha, IrohaGrpc
from iroha.primitive_pb2 import can_set_my_account_detail
import sys

if sys.version_info[0] < 3:
    raise Exception('Python 3 or a more recent version is required.')


IROHA_HOST_ADDR = os.getenv('IROHA_HOST_ADDR', '127.0.0.1')
IROHA_PORT = os.getenv('IROHA_PORT', '50051')
ADMIN_ACCOUNT_ID = os.getenv('ADMIN_ACCOUNT_ID', 'admin@test')
ADMIN_PRIVATE_KEY = os.getenv(
    'ADMIN_PRIVATE_KEY', 'f101537e319568c765b2cc89698325604991dca57b9716b58016b253506cab70')

user_private_key = IrohaCrypto.private_key()
user_public_key = IrohaCrypto.derive_public_key(user_private_key)
iroha = Iroha(ADMIN_ACCOUNT_ID)
net = IrohaGrpc('{}:{}'.format(IROHA_HOST_ADDR, IROHA_PORT))


def trace(func):
    """
    A decorator for tracing methods' begin/end execution points
    """

    def tracer(*args, **kwargs):
        name = func.__name__
        print('\tEntering "{}"'.format(name))
        result = func(*args, **kwargs)
        print('\tLeaving "{}"'.format(name))
        return result

    return tracer


@trace
def send_transaction_and_print_status(transaction):
    hex_hash = binascii.hexlify(IrohaCrypto.hash(transaction))
    print('Transaction hash = {}, creator = {}'.format(
        hex_hash, transaction.payload.reduced_payload.creator_account_id))
    net.send_tx(transaction)
    for status in net.tx_status_stream(transaction):
        print(status)


@trace
def create_domain_and_asset():
    """
    Creates domain 'domain' and asset 'coin#domain' with precision 2
    """
    commands = [
        iroha.command('CreateDomain', domain_id='domain', default_role='user'),
        iroha.command('CreateAsset', asset_name='coin',
                      domain_id='domain', precision=2)
    ]
    tx = IrohaCrypto.sign_transaction(
        iroha.transaction(commands), ADMIN_PRIVATE_KEY)
    send_transaction_and_print_status(tx)


@trace
def add_coin_to_admin():
    """
    Add 1000.00 units of 'coin#domain' to 'admin@test'
    """
    tx = iroha.transaction([
        iroha.command('AddAssetQuantity',
                      asset_id='coin#domain', amount='1000.00')
    ])
    IrohaCrypto.sign_transaction(tx, ADMIN_PRIVATE_KEY)
    send_transaction_and_print_status(tx)


@trace
def create_account_userone():
    """
    Create account 'userone@domain'
    """
    tx = iroha.transaction([
        iroha.command('CreateAccount', account_name='userone', domain_id='domain',
                      public_key=user_public_key)
    ])
    IrohaCrypto.sign_transaction(tx, ADMIN_PRIVATE_KEY)
    send_transaction_and_print_status(tx)


@trace
def transfer_coin_from_admin_to_userone():
    """
    Transfer 2.00 'coin#domain' from 'admin@test' to 'userone@domain'
    """
    tx = iroha.transaction([
        iroha.command('TransferAsset', src_account_id='admin@test', dest_account_id='userone@domain',
                      asset_id='coin#domain', description='init top up', amount='2.00')
    ])
    IrohaCrypto.sign_transaction(tx, ADMIN_PRIVATE_KEY)
    send_transaction_and_print_status(tx)


@trace
def userone_grants_to_admin_set_account_detail_permission():
    """
    Make admin@test able to set detail to userone@domain
    """
    tx = iroha.transaction([
        iroha.command('GrantPermission', account_id='admin@test',
                      permission=can_set_my_account_detail)
    ], creator_account='userone@domain')
    IrohaCrypto.sign_transaction(tx, user_private_key)
    send_transaction_and_print_status(tx)


@trace
def set_age_to_userone():
    """
    Set age to userone@domain by admin@test
    """
    tx = iroha.transaction([
        iroha.command('SetAccountDetail',
                      account_id='userone@domain', key='age', value='18')
    ])
    IrohaCrypto.sign_transaction(tx, ADMIN_PRIVATE_KEY)
    send_transaction_and_print_status(tx)


@trace
def get_coin_info():
    """
    Get asset info for coin#domain
    :return:
    """
    query = iroha.query('GetAssetInfo', asset_id='coin#domain')
    IrohaCrypto.sign_query(query, ADMIN_PRIVATE_KEY)

    response = net.send_query(query)
    data = response.asset_response.asset
    print('Asset id = {}, precision = {}'.format(data.asset_id, data.precision))


@trace
def get_account_assets():
    """
    List all the assets of userone@domain
    """
    query = iroha.query('GetAccountAssets', account_id='userone@domain')
    IrohaCrypto.sign_query(query, ADMIN_PRIVATE_KEY)

    response = net.send_query(query)
    data = response.account_assets_response.account_assets
    for asset in data:
        print('Asset id = {}, balance = {}'.format(
            asset.asset_id, asset.balance))


@trace
def get_userone_details():
    """
    Get all the kv-storage entries for userone@domain
    """
    query = iroha.query('GetAccountDetail', account_id='userone@domain')
    IrohaCrypto.sign_query(query, ADMIN_PRIVATE_KEY)

    response = net.send_query(query)
    data = response.account_detail_response
    print('Account id = {}, details = {}'.format('userone@domain', data.detail))


create_domain_and_asset()
add_coin_to_admin()
create_account_userone()
transfer_coin_from_admin_to_userone()
userone_grants_to_admin_set_account_detail_permission()
set_age_to_userone()
get_coin_info()
get_account_assets()
get_userone_details()

print('done')

Now, if you have irohad running, you can run the example or your own file by simply opening the .py file in another tab.