42 lines
1.0 KiB
Python
42 lines
1.0 KiB
Python
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# standard imports
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import os
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import sys
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# local imports
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from chainlib.jsonrpc import JSONRPCRequest
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from chainlib.chain import ChainSpec
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from chainlib.connection import (
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JSONRPCHTTPConnection,
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RPCConnection,
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ConnType,
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)
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# set up node connection and execute rpc call
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rpc_provider = os.environ.get('RPC_PROVIDER', 'http://localhost:8545')
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RPCConnection.register_constructor(ConnType.HTTP, JSONRPCHTTPConnection)
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tag = 'baz'
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chain_spec = ChainSpec('foo', 'bar', 42, tag=tag)
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RPCConnection.register_location(rpc_provider, chain_spec, tag='default')
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conn = RPCConnection.connect(chain_spec, 'default')
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# check the connection
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if not conn.check():
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sys.stderr.write('node {} not usable\n'.format(rpc_provider))
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sys.exit(1)
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# build and send rpc call
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g = JSONRPCRequest()
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o = g.template()
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o['method'] = 'eth_blockNumber'
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r = conn.do(o)
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# interpret result for humans
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try:
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block_number = int(r, 10)
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except ValueError:
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block_number = int(r, 16)
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print('block number {}'.format(block_number))
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