chainlib-eth

Ethereum implementation of the chainlib interface
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jsonrpc_factory.py (1035B)

      1 # standard imports
      2 import os
      3 import sys
      4 
      5 # local imports
      6 from chainlib.jsonrpc import JSONRPCRequest
      7 from chainlib.chain import ChainSpec
      8 from chainlib.connection import (
      9         JSONRPCHTTPConnection,
     10         RPCConnection,
     11         ConnType,
     12         )
     13 
     14 
     15 # set up node connection and execute rpc call
     16 rpc_provider = os.environ.get('RPC_PROVIDER', 'http://localhost:8545')
     17 RPCConnection.register_constructor(ConnType.HTTP, JSONRPCHTTPConnection)
     18 
     19 tag = 'baz'
     20 chain_spec = ChainSpec('foo', 'bar', 42, tag=tag)
     21 RPCConnection.register_location(rpc_provider, chain_spec, tag='default')
     22 conn = RPCConnection.connect(chain_spec, 'default')
     23 
     24 # check the connection
     25 if not conn.check():
     26     sys.stderr.write('node {} not usable\n'.format(rpc_provider))
     27     sys.exit(1)
     28 
     29 # build and send rpc call
     30 g = JSONRPCRequest()
     31 o = g.template()
     32 o['method'] = 'eth_blockNumber'
     33 r = conn.do(o)
     34 
     35 # interpret result for humans
     36 try:
     37     block_number = int(r, 10)
     38 except ValueError:
     39     block_number = int(r, 16)
     40 
     41 print('block number {}'.format(block_number))