fabric-samples/asset-transfer-basic/chaincode-java/README.md

Basic asset transfer

This project demonstrates the use of the Java SDK, running a basic asset transfer contract using the "chaincode as a service" pattern.

Setup

In this sample we will employ the Kubernetes Test Network to illustrate a scenario of building, running, and debugging chaincode on a development workstation.

This project is also compatible with the legacy chaincode builder pipeline and the compose based test-network. For additional details, see the End-to-end with the test-network documentation.

Quickstart

export PATH=${PWD}/../../test-network-k8s:$PATH 

network kind 

network up 
network channel create

network chaincode deploy    asset-transfer-basic basic_1.0 ${PWD}

network chaincode metadata  asset-transfer-basic
network chaincode invoke    asset-transfer-basic '{"Args":["InitLedger"]}'
network chaincode query     asset-transfer-basic '{"Args":["ReadAsset","asset1"]}' | jq 

Detailed Guide

network down
network up
network channel create

# Build the chaincode docker image 
docker build -t fabric-samples/asset-transfer-basic/chaincode-java .

# Load the docker image directly to the KIND control plane.  
# (Alternately, build/tag/push the image to a remote container registry, e.g. localhost:5000) 
kind load docker-image fabric-samples/asset-transfer-basic/chaincode-java

# Assemble the chaincode package archive 
network chaincode package basic_1.0 asset-transfer-basic $PWD/build/asset-transfer.tgz

# Determine the ID for the chaincode package 
CORE_CHAINCODE_ID_NAME=$(network chaincode id $PWD/build/asset-transfer.tgz)

# Launch the chaincode in k8s as Deployment + Service 
network chaincode launch asset-transfer-basic $CORE_CHAINCODE_ID_NAME fabric-samples/asset-transfer-basic/chaincode-java

# Complete the chaincode lifecycle 
network chaincode install $PWD/build/asset-transfer.tgz 
network chaincode approve asset-transfer-basic $CORE_CHAINCODE_ID_NAME
network chaincode commit  asset-transfer-basic

# execute the smart contract by name 
network chaincode metadata  asset-transfer-basic
network chaincode invoke    asset-transfer-basic '{"Args":["InitLedger"]}'
network chaincode query     asset-transfer-basic '{"Args":["ReadAsset","asset1"]}'

kubectl -n test-network logs -f deployment/org1peer1-ccaas-asset-transfer-basic

Debugging

Build

./gradlew shadowJar

or

docker build -t fabric-samples/asset-transfer-basic/chaincode-java . 

Package

By instructing the peer to connect to chaincode at the Docker host alias host.docker.internal, pods running in Kubernetes will access the local process via a special loopback interface established by KIND.

Set the "address" attribute in the package connection.json descriptor and assemble the chaincode package:

export TEST_NETWORK_CHAINCODE_ADDRESS=host.docker.internal:9999

network cc package basic_1.0 asset-transfer-debug $PWD/build/asset-transfer-debug.tgz

Launch

When chaincode is launched locally, it must declare the package ID in the environment as if the process had been managed by the peer's chaincode lifecycle manager. Calculate the package ID and start the chaincode, binding to port 9999 on the local system:

export CHAINCODE_SERVER_ADDRESS=0.0.0.0:9999
export CORE_CHAINCODE_ID_NAME=$(network chaincode id $PWD/build/asset-transfer-debug.tgz)

java -jar build/libs/chaincode.jar

Or using the editor/debugger/IDE of your choice, create a launch target for ContractMain.main(), specifying the environment as above.

Or launch the chaincode in a Docker container, binding to port 9999 on the host system:

docker run \
  --rm \
  --name basic_1.0 \
  -p 9999:9999 \
  -e CHAINCODE_SERVER_ADDRESS \
  -e CORE_CHAINCODE_ID_NAME \
  fabric-samples/asset-transfer-basic/chaincode-java

Approve, Invoke, and Query

After the contract main has launched, install, approve, commit, and invoke the chaincode:

# Complete the chaincode lifecycle 
network cc activate asset-transfer-debug $PWD/build/asset-transfer-debug.tgz 

# execute the smart contract by name 
network cc metadata asset-transfer-debug
network cc invoke   asset-transfer-debug '{"Args":["InitLedger"]}'
network cc query    asset-transfer-debug '{"Args":["ReadAsset","asset1"]}'

Tear Down

network down 

or

network unkind