This is the source code for a toy block chain introduced here
PyNaiveChain is a toy blockchain implemented completly in python. It has the following features as of now
- Peer discovery of a loosely implemented gossip protocol
- Simple consensus based data addition
- Dedicated WebSocket Communication layer implemetation
- Protocol Processing for inter-node comuunication
- Flask based HTTP Layer for handling client requests
What it doesn't have at the moment:
- Proof of work/Proof of stake based consensus
- Proper implementation of node discovery
- Block Data persistence
- Chain reparing
Note: This only supports python 3, it is not compatible with Python 2.
Setup the virtual environment and install all the requirements
python3 -m venv env
source env/bin/activate
pip install -r requirements.txtCheck out the startup script for information about different options:
python start_node --help
usage: start_node.py [-h] [-pid PEER_ID] [-pport PEER_PORT] [-p PORT]
optional arguments:
-h, --help show this help message and exit
-pid PEER_ID, --peer_id PEER_ID Id of the peer to synce from after startup
-pport PEER_PORT, --peer_port PEER_PORT Port of the peer to connect to
-p PORT, --port PORT Port for the instance
Once you are done installing the requirements, you can start by firing up a single node.
python start_node.py -p 15001You should see outlogs like this
[INFO]: BLOCKCHAIN-Setting up naive chain server
[INFO]: BLOCKCHAIN-Intializing websocket RPC
[INFO]: RPC_SERVER-Intializing RPC server
[INFO]: BLOCKCHAIN-Intializing websocket RPC
[INFO]: BLOCKCHAIN-Intializing protocol processing
[INFO]: PROTOCOL_PROCESSOR-Intializing protocol processor
[INFO]: RPC_SERVER-Starting RPC server on port 0.0.0.0:15001
[INFO]: RPC_SERVER-RPC server waiting for connections
[INFO]: BLOCKCHAIN-Node 7a02e5b3-de28-49e5-947f-93a2c15d1d47 live on 0.0.0.0:15001
[INFO]: BLOCKCHAIN-No Peer Specified. Intializing genesis block for standalone operation
* Serving Flask app "http_server" (lazy loading)
* Environment: production
WARNING: Do not use the development server in a production environment.
Use a production WSGI server instead.
* Debug mode: off
* Running on http://0.0.0.0:15002/ (Press CTRL+C to quit)
The http server starts on websocket port + 1. You can access HTTP based RPCs on :
Running on http://0.0.0.0:15002/ (Press CTRL+C to quit)
The Node id is displayed in the output log:
[INFO]: BLOCKCHAIN-Node 7a02e5b3-de28-49e5-947f-93a2c15d1d47 live on 0.0.0.0:15001
NOTE: Currently, a single node will not let you add any data. You need atleast 2 nodes to add any kind of data.
Start a single node as shown in the previous section , and copy it's port and node id.(this example is going to use the node from above as the pre-exsiting peer.
python start_node.py -pid 7a02e5b3-de28-49e5-947f-93a2c15d1d47 -pport 15001 -p 9803
This should display the same output as above:
[INFO]: BLOCKCHAIN-Setting up naive chain server
[INFO]: BLOCKCHAIN-Intializing websocket RPC
[INFO]: RPC_SERVER-Intializing RPC server
[INFO]: BLOCKCHAIN-Intializing websocket RPC
[INFO]: BLOCKCHAIN-Intializing protocol processing
[INFO]: PROTOCOL_PROCESSOR-Intializing protocol processor
[INFO]: RPC_SERVER-Starting RPC server on port 0.0.0.0:9803
[INFO]: RPC_SERVER-RPC server waiting for connections
[INFO]: BLOCKCHAIN-Node be809443-c21f-4130-9ba8-b18a8f6e7e56 live on 0.0.0.0:9803
[INFO]: BLOCKCHAIN-Peer Discovered
[INFO]: BLOCKCHAIN-Joining remote peer
[INFO]: BLOCKCHAIN-Intializing data sync peer
[INFO]: PROTOCOL_PROCESSOR-NEW_PEER_JOIN_DATA_UPLOAD recieved
[INFO]: PROTOCOL_PROCESSOR-Saving data from remote peer
* Serving Flask app "http_server" (lazy loading)
* Environment: production
WARNING: Do not use the development server in a production environment.
Use a production WSGI server instead.
* Debug mode: off
* Running on http://0.0.0.0:9804/ (Press CTRL+C to quit)
This is the same as above, but our new node gets all the info from the existing node as well:
[INFO]: BLOCKCHAIN-Peer Discovered
[INFO]: BLOCKCHAIN-Joining remote peer
[INFO]: BLOCKCHAIN-Intializing data sync peer
[INFO]: PROTOCOL_PROCESSOR-NEW_PEER_JOIN_DATA_UPLOAD recieved
[INFO]: PROTOCOL_PROCESSOR-Saving data from remote peer
You can add as many nodes as like this desired.
All the nodes expose all their functionality throught HTTP endpoints
| Name | End Point | Method | Description |
|---|---|---|---|
| Add Data | /data | POST | Add new data to the blockchain(TODO: Change this to PUT) |
| Get Data | /data | GET | Get all the data currently residing in the blockchain |
| Node Info | /node | GET | Get all information against a node |
| Get Peers | /peers | GET | Get all the peers of a node |
Request:
curl -X POST \
http://127.0.0.1:15002/data \
-H 'Cache-Control: no-cache' \
-H 'Content-Type: application/json' \
-d '{"data": "Testing String Again"}'
Response:
{"status": "OK", "data": true}
Request:
curl -X GET http://127.0.0.1:15002/data
Response:
{
"status":"OK",
"data":[
{
"index":0,
"previous_hash":"ioiiiuasyi891qbduquiuqwiqwiupwe",
"data":"\"random\"",
"curr_hash":"71fbc6a1c90d94050b32ab9f9d6a11fc41724f8f954905c120c4c16b71f1f80f"
},
{
"index":1,
"previous_hash":"71fbc6a1c90d94050b32ab9f9d6a11fc41724f8f954905c120c4c16b71f1f80f",
"data":"\"Testing String Again\"",
"curr_hash":"c8a8924ed4d8c58638b9f4fcbb7609bb0edb4a509d1514246a04ebba680d5a1f"
}
]
}
Request:
curl -X GET http://127.0.0.1:15002/node
Response:
{
"status":"OK",
"data":{
"peer_id":"7a02e5b3-de28-49e5-947f-93a2c15d1d47",
"data_count":2,
"health":true,
"rpc_port":"15001",
"age":"2018-06-02 12:42:13.860551"
}
}
Request:
curl -X GET http://127.0.0.1:15002/peers
Response:
{
"status":"OK",
"data":{
"01cfb470-65a3-4267-a33c-28be309b5887":{
"host":"0.0.0.0",
"port":"9803"
}
}
}