Pre-requisites

These are the tools you would need to follow this tutorial

1. Install docker and verify that docker is working

   https://docs.docker.com/engine/installation/

   docker run hello-world

   After installation verify the docker daemon is listening on tcp port.

   Ubuntu follow these steps as the default service daemon does not listen on tcp port,

   sudo service stop docker
   sudo docker daemon -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock
   

2. Install docker-compose, which we will use to bring up multiple docker containers easily.

   https://docs.docker.com/compose/install/

Example

1. Clone this repository or download the archive from Github.
2. Run the following command, this pulls 2 images and runs a network of 2 peers

• fabric-peer which hosts the hyperledger fabric backend
• fabric-javaenv which is the runtime image for java chaincodes

  	cd docker-compose
  	docker-compose up
  

3. Open another terminal in the same directory and start the fabric-peer container to issue deploy and invoke transactions

   docker-compose run vp1 bash

4. Once you are inside the container deploy the given example,

   peer chaincode deploy --logging-level debug -l java -p examples/chaincode/java/SimpleSample -c '{"Function": "init", "Args": ["alice","100", "bob", "200"]}'

   17:23:38.936 [logging] LoggingInit -> DEBU 001 Setting default logging level to DEBUG for command 'chaincode'
   17:23:39.131 [chaincodeCmd] chaincodeDeploy -> INFO 002 Deploy result: type:JAVA chaincodeID:<path:"examples/chaincode/java/SimpleSample" name:"771df7c1cfa4dd9607c72ec190c8e7f1954c1d431c08017496097c3007cd06e4902aa49e7385a1b8ab75111fa66a17cd7094d8b8a325de62d33bf8014e62dcf0" > ctorMsg:<args:"init" args:"alice" args:"100" args:"bob" args:"200" > 
   17:23:39.131 [main] main -> INFO 003 Exiting.....
   

   Note the value for 'name' from the response. This is like a unique identifier for the chaincode that was just deployed. This will be reused as a parameter in the following commands.

5. Query the initial state of the accounts,

   peer chaincode query -l java \
   -n 771df7c1cfa4dd9607c72ec190c8e7f1954c1d431c08017496097c3007cd06e4902aa49e7385a1b8ab75111fa66a17cd7094d8b8a325de62d33bf8014e62dcf0 \
   -c '{ "Function": "query", "Args": ["alice"]}'
   

   peer chaincode query -l java \
   -n 771df7c1cfa4dd9607c72ec190c8e7f1954c1d431c08017496097c3007cd06e4902aa49e7385a1b8ab75111fa66a17cd7094d8b8a325de62d33bf8014e62dcf0 \
   -c '{ "Function": "query", "Args": [ "bob"]}'
   

6. Invoke a transaction on the example,

   peer chaincode invoke -l java \
   	-n 771df7c1cfa4dd9607c72ec190c8e7f1954c1d431c08017496097c3007cd06e4902aa49e7385a1b8ab75111fa66a17cd7094d8b8a325de62d33bf8014e62dcf0 \
   	-c '{ "Function": "transfer",  "Args": [ "alice", "bob", "10"]}'
   

7. Query the state of the accounts again,

   peer chaincode query -l java \
   	-n 771df7c1cfa4dd9607c72ec190c8e7f1954c1d431c08017496097c3007cd06e4902aa49e7385a1b8ab75111fa66a17cd7094d8b8a325de62d33bf8014e62dcf0 \
   	-c '{ "Args": ["query", "alice"]}'
   

   peer chaincode query -l java \
   	-n 771df7c1cfa4dd9607c72ec190c8e7f1954c1d431c08017496097c3007cd06e4902aa49e7385a1b8ab75111fa66a17cd7094d8b8a325de62d33bf8014e62dcf0 \
   	-c '{ "Args": ["query", "bob"]}'
   

Repo Contract example

This example is located under docker-compose/project/repoChaincode. This project folder is mapped to the peer docker container and made available as /root/ volume. So any changes made to this folder will get reflected in the docker container.

1. Deploy the Repo contract chaincode using the following command

   peer chaincode deploy --logging-level debug -l java -p /root/project/repoChaincode -c '{"Function": "init", "Args": []}'
   

2. Dealer X with 2 trades, Trade-1 between ML 9510 and JPMorgan 9512

   peer chaincode invoke -l java \
   -n fb14710b9ca328fcff5784e7f99ff94277b369f05f39ee869c112821e08c7437add98f4ab3d54c702aabfd018ff0585a195d3c76e83a73de20002b9585d18855 \
   -c '{"Function": "instruct", "Args": ["XREF-MLJPM1", "TID1001", "9510", "9512", "0.34", "8000000", "100000", "371487AE9"]}'
   

3. And a Trade-2 between ML 9510 and HSBC 9513

   peer chaincode invoke -l java \
   -n fb14710b9ca328fcff5784e7f99ff94277b369f05f39ee869c112821e08c7437add98f4ab3d54c702aabfd018ff0585a195d3c76e83a73de20002b9585d18855 \
   -c '{"Function": "instruct", "Args": ["XREF-MLHSBC", "TID1002", "9510", "9513", "0.36", "5000000", "20000", "371487AE9"]}'
   

4. Now Dealer Y comes with a matching trade for XREFMLJPM1

   peer chaincode invoke -l java \
   -n fb14710b9ca328fcff5784e7f99ff94277b369f05f39ee869c112821e08c7437add98f4ab3d54c702aabfd018ff0585a195d3c76e83a73de20002b9585d18855 \
   -c '{"Function": "instruct", "Args": ["XREF-BRK1MLJPM", "TIDX002", "9512", "9510", "0.34", "8000000", "100000", "371487AE9"]}'
   

5. Once this transaction is made, it is matched with existing trade and the trades gets updated accordingly.

   peer chaincode query -l java \
   -n fb14710b9ca328fcff5784e7f99ff94277b369f05f39ee869c112821e08c7437add98f4ab3d54c702aabfd018ff0585a195d3c76e83a73de20002b9585d18855 \
   -c '{"Function": "trades", "Args": ["", ""]}'
   

Development of chaincodes

Please follow the repoChaincode example in the projects folder and modify build.gradle for your needs,

• Make your main class extend ChaincodeBase class and implement the following methods from base class.

    public String run(ChaincodeStub stub, String function, String[] args)
    public String query(ChaincodeStub stub, String function, String[] args)
    public String getChaincodeID()

• Implement the main method to instantiate and run the start() method.
• Modify the mainClassName in build.gradle to point to your new class.