164 lines
5.0 KiB
Python
164 lines
5.0 KiB
Python
# Interacting with the Dexter's blockchain with multiple nodes using HTTP requests
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from flask import Flask, jsonify, request
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from blockChain import Blockchain
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# Initialise our node with identifier and instantiate the Blockchain class
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app = Flask(__name__)
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blockchain = Blockchain()
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# API endpoint to mine a block, it is an HTTP GET request
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@app.route('/mine', methods=['GET'])
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# Method to mine a block
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def mine():
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# To ensure that only delegates elected by voting can mine a new block
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current_port = "localhost:" + str(port)
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if current_port in blockchain.delegates:
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# To ensure that a new block is mined only if there are atleast 2 transactions
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if len(blockchain.unverified_transactions) >= 2:
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last_block = blockchain.last_block
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previous_hash = blockchain.hash(last_block)
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block = blockchain.new_block(previous_hash)
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response = {
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'message': "New block mined!",
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'index': block['index'],
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'transactions': block['transactions'],
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'previous_hash': block['previous_hash']
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}
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print(len(blockchain.unverified_transactions))
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return jsonify(response), 200
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else:
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response = {
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'message': 'Not enough transactions to mine a new block and add to chain!'
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}
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print(len(blockchain.unverified_transactions))
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return jsonify(response), 400
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else:
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response = {
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'message': 'You are not authorised to mine block! Only delegates can mine.'
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}
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return jsonify(response), 400
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# Endpoint for a new transaction
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@app.route('/transactions/new', methods=['POST'])
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def new_transaction():
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values = request.get_json()
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required = ['Customer name', 'Item name', 'Total billing amount']
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if not all(k in values for k in required):
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return 'Missing values! Please enter customer name, item name and billing amount.', 400
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index = blockchain.new_transaction(values['Customer name'], values['Item name'], values['Total billing amount'])
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response = {
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'message': f'Transaction will be added to block {index}'
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}
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return jsonify(response), 201
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# Endpoint for viewing the blockchain
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@app.route('/chain', methods=['GET'])
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def full_chain():
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response = {
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'chain': blockchain.chain,
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'length': len(blockchain.chain)
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}
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return jsonify(response), 200
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# Endpoint for adding HTTP address of new nodes along with their stakes in the network.
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@app.route('/nodes/add', methods=['POST'])
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def add_nodes():
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values = request.get_json()
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required = ['nodes', 'stake']
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if not all(k in values for k in required):
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return 'Error', 400
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blockchain.add_node(values['nodes'], values['stake'])
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response = {
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'message': 'New nodes are added!',
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'total_nodes': list(blockchain.nodes)
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}
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print(blockchain.nodes)
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return jsonify(response), 201
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# Endpoint to start the voting process
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@app.route('/voting', methods=['GET'])
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def voting():
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if port == 5000:
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show_votes = blockchain.add_vote()
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response = {
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'message': 'The voting results are as follows:',
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'nodes': blockchain.voteNodespool
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}
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return jsonify(response), 200
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else:
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response = {
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'message': 'You are not authorized to conduct the election process!'
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}
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return jsonify(response), 400
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# Endpoint to view the list of all three elected delegate nodes
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@app.route('/delegates/show', methods=['GET'])
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def delegates():
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show_delegates = blockchain.selection()
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response = {
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'message': 'The 3 delegate nodes selected for block mining are:',
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'node_delegates': blockchain.delegates
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}
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return jsonify(response), 200
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# Endpoint to synchronise the list of elected delegates with all other nodes in the network
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@app.route('/delegates/sync', methods=['GET'])
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def sync_delegates():
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sync_delegates = blockchain.sync()
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response = {
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'message': 'The delegate nodes are:',
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'node_delegates': blockchain.delegates
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}
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return jsonify(response), 200
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# Endpoint to resolve and replace current chain with the longest validated one,achieving consensus
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@app.route('/chain/resolve', methods=['GET'])
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def consensus():
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replaced = blockchain.resolve_chain()
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if replaced:
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response = {
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'message': 'Our chain was replaced',
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'new_chain': blockchain.chain
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}
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else:
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response = {
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'message': 'Our chain is authoritative',
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'chain': blockchain.chain
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}
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return jsonify(response), 200
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if __name__ == '__main__':
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from argparse import ArgumentParser
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parser = ArgumentParser()
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parser.add_argument('-p', '--port', default=5000, type=int, help='Listening on port')
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args = parser.parse_args()
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port = args.port
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app.run(host='0.0.0.0', port=port)
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