Hyperledger Fabric Client SDK for Node.js

The Hyperledger Fabric Client SDK (HFC) makes it easy to use APIs to interact with a Hyperledger Fabric blockchain.

As an application developer, to learn about how to install and use the Node.js SDK, please visit the fabric documentation.

The following section targets a current or future contributor to this project itself.

Build and Test

To build and test, the following pre-requisites must be installed first:

• node runtime version 4.5 or later (which also installs the npm tool)
• npm tool version 2.15.9 or later
• gulp command
• docker (not required if you only want to run the headless tests with npm test, see below)

Clone the project and launch the following commands to install the dependencies and perform various tasks.

This project publishes two separate npm packages:

• hfc - main client for the Hyperledger Fabric. Applications can use this package to deploy chaincodes, submit transactions and make queries against a Hyperledger Fabric-based blockchain network.
• hfc-cop - client for the optional component in Hyperledger Fabric, COP. The COP component allows applications to enroll Peers and application users to establish trusted identities on the blockchain network. It also provides support for pseudonymous transaction submissions with Transaction Certificates. If the target blockchain network is configured with standard Certificate Authorities for trust anchors, then the application does not need to use this package.

In the project root folder:

• npm install to install dependencies
• gulp cop to copy common dependent modules from the hfc folder to the hfc-cop folder
• gulp watch to set up watch that updates hfc-cop's shared dependencies from hfc/lib and updates installed hfc and hfc-cop modules in node_modules. This command does not return, so you should keep it running in a separate command window as you work on the code and test in another command window
• optionally, gulp doc to generate API docs if you want to review the doc content
• npm test to run the headless tests that do not require any additional set up

The following tests require setting up a local blockchain network as the target. Because v1.0 is still in active development, you still need the vagrant environment to build the necessary Docker images needed to run the network. Follow the steps below to set it up.

• You will need the COP server (new implementation of the member service) to run the tests. Because the COP project's build script does not yet produce a docker image, you'd need to run the COP server as a native process inside vagrant
• git clone both the fabric and fabric-cop repositories into the $GOPATH/src/github.com/hyperledger folder in your native host (MacOS, Windows or Ubuntu, etc).

If you are using a Mac and would like to build the docker images and run them natively instead of using vagrant, do the following:

• If docker is installed and it’s not ‘Docker for Mac’, uninstall and follow Docker’s clean up instructions to uninstall completely.

• Install ‘Docker for Mac’.

• Install Brew: http://brew.sh

• run brew install gnu-tar —-with-default-names

• To use vagrant, do the following:

• cd fabric/devenv

• Open the file Vagrantfile and insert the following statement below the existing config.vm.network statements:

  • config.vm.network :forwarded_port, guest: 7056, host: 7056 # Openchain gRPC services
  • config.vm.network :forwarded_port, guest: 8888, host: 8888 # COP services

• run vagrant up to launch the vagrant VM

• Once inside vagrant, follow these steps to start the COP server and the Peers network with orderer

• start COP (new membership service)

  • cd `$GOPATH/src/github.com/hyperledger/fabric-cop
  • run make cop to build the COP binary or follow the instructions in fabric-cop README
  • from the fabric-cop folder, launch the following command to start the COP server. The ec.pem and ec-key.pem certificates sets up the COP server as the trusted root that the Peer nodes have been statically configured as a temporary measure. In other words, the Peers will be able to trust any user certificates that have been signed by the COP server. This is important because the endorser code inside the Peer will need to validate the user certificate issued by COP before using it to verify the signature of the transaction proposal.
    • bin/cop server start -address "" -ca testdata/ec.pem -ca-key testdata/ec-key.pem -config testdata/testconfig.json

• start the Peer network

  • cd $GOPATH/src/github.com/hyperledger/fabric
  • run make docker to build the docker images
  • create a docker-compose.yml file in home directory (/home/vagrant), and copy docker-compose.yml file content into the file
  • from /home/vagrant, run docker-compose up --force-recreate to launch the network

• Back in your native host (MacOS, or Windows, or Ubuntu, etc), run the following tests:

  • Clear out your previous keyvalue store if needed for fabric-sdk-node (rm -fr /tmp/hfc-*) and for fabric-cop (rm $HOME/.cop/cop.db)
  • Run gulp test to run the entire test bucket and generate coverage reports (both in console output and HTMLs)
  • Test user management with a member services, run node test/unit/ca-tests.js
  • Test happy path from end to end, run node test/unit/end-to-end.js
  • Test transaction proposals, run node test/unit/endorser-tests.js
  • Test sending endorsed transactions for consensus, run node test/unit/orderer-tests.js

Contributor Check-list

The following check-list is for code contributors to make sure their changesets are compliant to the coding standards and avoid time wasted in rejected changesets:

Check the coding styles, run the following command and make sure no ESLint violations are present:

• gulp

Run the full unit test bucket and make sure 100% are passing:

• gulp test

The gulp test command above also generates code coverage reports. Your new code should be accompanied with unit tests and pass 80% lines coverage or above.

HFC objects and reference documentation

For a high-level design specificiation for Fabric SDKs of all languages, visit this google doc (Work-In-Progress).

HFC is written in CommonJS modules and is object-oriented. It's comprised of the following modules.

• index.js is the top-level module that provides the main API surface into the HFC package. It's mainly a collection of convenient methods.
• The main top-level class is Chain. It is the client's view of a blockchain network. HFC allows you to interact with multiple chains. Each chain object can be configured with a different member service or share a common member service, depending on how the target blockchain networks are set up. Each chain object has a KeyValueStore to store private keys and certificates for authenticated users. Each chain object can be configured with an ordering service, to which HFC connects to send transactions for consensus and committing to the ledger.
• The KeyValueStore is a very simple interface which HFC uses to store and retrieve all persistent data. This data includes private keys, so it is very important to keep this storage secure. The default implementation is a simple file-based version found in the FileKeyValueStore class.
• The MemberServices interface provides security and identity related features such as user registration and enrollment, transaction certificate issuance. The Hyperledger Fabric has a built-in implementation that issues ECerts (enrollment certificates) and TCerts (transaction certificates). ECerts are for enrollment identity and TCerts are for transactions.
• The Member class represents an end user who transacts on the chain. From the Member class, you can register and enroll users. This class interacts with the MemberServices object. You can also deploy, query, and invoke chaincode from this class, which interact with the Peer objects.
• The EventHub class encapsulates the interaction with the network peers' event streams.

Pluggability

HFC defines the following abstract classes for application developers to supply extensions or alternative implementations. For each abstract class, a built-in implementation is included with the ability to load alternative implementations via designated environment variables:

1. To replace FileKeyValueStore with a different implementation, such as one that saves data to a database, specify "KEY_VALUE_STORE" and provide the full require() path to an alternative implementation of the api.KeyValueStore abstract class.

2. The cryptography suite used by the default implementation uses ECDSA for asymmetric keys cryptography, AES for encryption and SHA2/3 for secure hashes. A different suite can be plugged in with "CRYPTO_SUITE" environment variable specifying full require() path to the alternative implementation of the api.CrytoSuite abstract class.

3. If the user application uses an alternative membership service than the one provided by the component fabric-cop, the client code will likely need to use an alternative client to hfc-cop to interact with that membership service.