Incubation Notice

This is a Hyperledger project in Incubation. It was proposed to the community and documented here. Information on what Incubation entails can be found in the Hyperledger Project Lifecycle document.

Overview

This project contains the core blockchain fabric code, development environment scripts, and documents for developers to contribute fabric code or work on their own applications.

• Building the fabric core
• Building outside of Vagrant
• Code contributions
• Communication
• Coding Golang
• Writing Chaincode
• Setting Up a Network
• Working with CLI, REST, and Node.js
• Configuration
• Logging
• Generating gRPC code
• Adding or updating Go packages

License

This software is made available under the Apache License Version 2.0.

Building the fabric core

The following instructions assume that you have followed the development environment getting started instructions.

To access your VM, run

vagrant ssh

From within the VM, you can build, run, and test your environment.

1. Go build

cd $GOPATH/src/github.com/hyperledger/fabric/peer
go build

2. Run/Execute

To see what commands are available, simply execute the following commands:

cd $GOPATH/src/github.com/hyperledger/fabric/peer
./peer

You should see some output similar to below (NOTE: The root command below is hardcoded in the main.go and the build creates the peer executable).

    Usage:
      peer [command]

    Available Commands:
      peer        Runs the peer.
      status      Returns status of the peer.
      stop        Stops the running peer.
      login       Logs in a user on CLI.
      network     Lists all network peers.
      chaincode   chaincode specific commands.
      help        Help about any command

    Flags:
      -h, --help[=false]: help for peer
          --logging-level="": Default logging level and overrides, see core.yaml for full syntax


    Use "peer [command] --help" for more information about a command.

The peer command will initiate a peer process, with which one can interact by executing other commands. For example, the status command will return the status of the running peer.

3. Test

New code must be accompanied by test cases both in unit and Behave tests.

3.1 Unit Tests

To run all unit tests, in one window, run ./peer peer. In a second window

cd $GOPATH/src/github.com/hyperledger/fabric
go test -timeout=20m $(go list github.com/hyperledger/fabric/... | grep -v /vendor/ | grep -v /examples/)

Note that the first time the tests are run, they can take some time due to the need to download a docker image that is about 1GB in size. This is why the timeout flag is added to the above command.

To run a specific test use the -run RE flag where RE is a regular expression that matches the test case name. To run tests with verbose output use the -v flag. For example, to run the TestGetFoo test case, change to the directory containing the foo_test.go and call/excecute

go test -v -run=TestGetFoo

3.2 Behave Tests

Behave tests will setup networks of peers with different security and consensus configurations and verify that transactions run properly. To run these tests

cd $GOPATH/src/github.com/hyperledger/fabric/bddtests
behave

Some of the Behave tests run inside Docker containers. If a test fails and you want to have the logs from the Docker containers, run the tests with this option

behave -D logs=Y

Note, you must run the unit tests first to build the necessary peer and member services docker images. These images can also be individually built when go test is called with the following parameters:

go test github.com/hyperledger/fabric/core/container -run=BuildImage_Peer
go test github.com/hyperledger/fabric/core/container -run=BuildImage_Obcca

Building outside of Vagrant

While not recommended, it is possible to build the project outside of Vagrant (e.g., for using an editor with built-in Go toolking). In such cases:

• Follow all steps required to setup and run a Vagrant image:
  • Make sure you you have Go 1.6 installed
  • Set the maximum number of open files to 10000 or greater for your OS
  • Install RocksDB version 4.1 and its dependencies

apt-get install -y libsnappy-dev zlib1g-dev libbz2-dev
cd /tmp
git clone https://github.com/facebook/rocksdb.git
cd rocksdb
git checkout v4.1
PORTABLE=1 make shared_lib
INSTALL_PATH=/usr/local make install-shared

• Execute the following commands:

cd $GOPATH/src/github.com/hyperledger/fabric/peer
CGO_CFLAGS=" " CGO_LDFLAGS="-lrocksdb -lstdc++ -lm -lz -lbz2 -lsnappy" go install

• Make sure that the Docker daemon initialization includes the options

-H tcp://0.0.0.0:4243 -H unix:///var/run/docker.sock

• Be aware that the Docker bridge (the CORE_VM_ENDPOINT) may not come up at the IP address currently assumed by the test environment (172.17.0.1). Use ifconfig or ip addr to find the docker bridge.

Code contributions

We welcome contributions to the Hyperledger Project in many forms. There's always plenty to do! Full details of how to contribute to this project are documented in the CONTRIBUTING.md file.

Communication

We use Hyperledger Slack for communication and Google Hangouts™ for screen sharing between developers.

For general purpose questions, use StackOverflow. Even if questions are answered through Hyperledger Slack, please post them to StackOverflow so answers don't have to be repeated continuously.

Coding Golang

• We require a file header in all source code files. Simply copy and paste the header when you create a new file.
• We code in Go™ and strictly follow the best practices and will not accept any deviations. You must run the following tools against your Go code and fix all errors and warnings:
  • golint
  • go vet

Writing Chaincode

Since chaincode is written in Go language, you can set up the environment to accommodate the rapid edit-compile-run of your chaincode. Follow the instructions on the Sandbox Setup page, which allows you to run your chaincode off the blockchain.

Setting Up a Network

To set up an development network composed of several validating peers, follow the instructions on the Devnet Setup page. This network leverages Docker to manage multiple peer instances on the same machine, allowing you to quickly test your chaincode.

Working with CLI, REST, and Node.js

When you are ready to start interacting with the peer node through the available APIs and packages, follow the instructions on the CoreAPI Documentation page.

Configuration

Configuration utilizes the viper and cobra libraries.

There is a core.yaml file that contains the configuration for the peer process. Many of the configuration settings can be overridden on the command line by setting ENV variables that match the configuration setting, but by prefixing with 'CORE_'. For example, logging level manipulation through the environment is shown below:

CORE_PEER_LOGGING_LEVEL=CRITICAL ./peer

Logging

Logging utilizes the go-logging library.

The available log levels in order of increasing verbosity are: CRITICAL | ERROR | WARNING | NOTICE | INFO | DEBUG

See specific logging control instructions when running the peer process.

Generating gRPC code

If you modify any .proto files, run the following command to generate/update the respective .pb.go files.

$GOPATH/src/github.com/hyperledger/fabric/devenv/compile_protos.sh

Adding or updating Go packages

The Hyperledger Fabric Project uses Go 1.6 vendoring for package management. This means that all required packages reside in the /vendor folder within the fabric project. Go will use packages in this folder instead of the GOPATH when the go install or go build commands are executed. To manage the packages in the /vendor folder, we use Govendor, which is installed in the Vagrant environment. The following commands can be used for package management:

# Add external packages.
govendor add +external

# Add a specific package.
govendor add github.com/kardianos/osext

# Update vendor packages.
govendor update +vendor

# Revert back to normal GOPATH packages.
govendor remove +vendor

# List package.
govendor list