Example App

This project is an example app demonstrating some of the Hyperledger/fabric capabilities. This app uses both the Node.js SDK and the REST interface. The features that display information about the blockchain and its transactions primarily use the REST interface while the features that execute chaincode transactions use the SDK.

Installation

git clone https://github.com/ericmvaughn/blocks.git

npm install -g gulp
npm install -g mocha
npm install

Setting up a test blockchain

Bluemix blockchain

To get started you will need an account on Bluemix.

Provision the blockchain service from the list of Application services.

Open up the management panel for the blockchain service and select the "Service Credentials" tab and then select "View Credentials". Copy and paste the credentials into a file named something similar to cred-blockchain-ma.json.

Modify the api_url lines from http to https.

Edit the following line in both api.js and util.js to match your credentials filename.

var cred = require('./cred-blockchain-ma.json');

Start the node server in the directory the app was installed in.

node api.js

Connect to the node server from a browser using http://localhost:3000

Vagrant local blockchain

Follow the instructions from the Hyperledger Fabric project to install Vagrant and the fabric source. Using windows start 3 git-bash consoles in administrator mode.

In the first console build the vagrant environment which can take some time.

cd $GOPATH/src/github.com/hyperledger/fabric/devenv/
vagrant up

Once this completes login to the vagrant image.

vagrant ssh

Initial Installation

If fabric hasn't be built yet then do the following.

cd /hyperledger
make all

Delete the block chain created during the build process

rm -r /var/hyperledger/production/

Also delete the files under tmp/keyValStore in the blocks source directory. Note: Only delete these files the first time you run or anytime you delete the /var/hyperledger/production directory in vagrant.

Next start the member services.

cd /hyperledger/
export MEMBERSRVC_CA_ACA_ENABLED=true
 ./build/bin/membersrvc

In the second window start a validating peer.

cd $GOPATH/src/github.com/hyperledger/fabric/devenv/
vagrant ssh
cd /hyperledger/
export CORE_SECURITY_ENABLED=true
export CORE_SECURITY_PRIVACY=true
./build/bin/peer node start

In the third console start the node server in the directory the app was installed in.

node api.js

At this point you can connect from a browser using http://localhost:3000

Deploying chaincode with the SDK in windows

This is the current workaround for deploying chaincode from a node app running under windows with the SDK. The basic approach here is to create the chaincode in the Vagrant environment and build it. Then copy the whole directory back to windows.

Inside the Vagrant environment do the following.

cd $GOPATH/src/github.com/
git clone https://github.com/blocledger/blocks_chaincode.git
cd blocks_chaincode
mkdir -p vendor/github.com/hyperledger
cd vendor/github.com/hyperledger
cp -r $GOPATH/src/github.com/hyperledger/fabric .
cp -r fabric/vendor/github.com/op ..
cd ../../..
go build

Now copy the whole blocks_chaincode directory back to windows and put it in $GOPATH/src/github.com

To invoke the deploy from your browser go to URL localhost:3000/deploy

NOTE: The Vagrant steps were gleaned from fabric/sdk/node/bin/run-unit-tests.sh.

Deploying chaincode with the REST interface

Alternatively the REST interface can be used to deploy the chaincode from the Github repository. The postman app works well for this.

First step is to register one of the users defined in the membersrvc.yaml file.

POST http://localhost:7050/registrar

BODY
{
      "enrollId": "jim",
      "enrollSecret": "6avZQLwcUe9b"
}


POST  http://localhost:7050/chaincode

body
{
  "jsonrpc": "2.0",
  "method": "deploy",
  "params": {
    "type": 1,
    "chaincodeID":{
        "path":"https://github.com/ericmvaughn/blocks_chaincode"
    },
    "ctorMsg": {
        "function":"init",
        "args":["a", "1000", "b", "2000"]
    },
    "secureContext": "jim"
  },
  "id": "1"  
}

results
{
  "jsonrpc": "2.0",
  "result": {
    "status": "OK",
    "message": "77dcb5e38265da1ef3f51edee25b3612085bcbd26262da4236da5ceb4387a655a3c60476c4aed35e1ca78dcdb6417a7e4c88965aa88ffa39878c7c8bde2a0772"
  },
  "id": "1"
}

The message value in the results contains the chaincode ID that needs to be saved in the tmp/keyValStore/chaincodeID file.

NOTE: A restart of node may be required at this point.

Testing

To run both the linter and code style checker run gulp with no parameters.

To run testing that will generate transactions and exercise all of the server capabilities run gulp test.

Debugging

Turn additional debug prints and/or GRPC tracing with

DEBUG=hfc,blocks node api.js
  or
DEBUG=hfc,blocks GRPC_TRACE=all node api.js

Acknowledgement

This project was based heavily on the IBM Marbles example and the Hyperledger fabric project.

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