Openchain - Peer

Overview

This project contains the core blockchain fabric.

Building the project

Assuming you have followed the development environment getting started instructions

To access your VM, run

vagrant ssh

From within the VM, follow these additional steps.

Go build

cd $GOPATH/src/github.com/openblockchain/obc-peer
go build

Run

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

cd $GOPATH/src/github.com/openblockchain/obc-peer
./obc-peer

You should see some output similar to below (NOTE: rootcommand below is hardcoded in the main.go. Current build will actually create an obc-peer executable file).

    Usage:
      obc-peer [command]

    Available Commands:
      peer        Run obc peer.
      status      Status of the obc peer.
      stop        Stops the obc peer.
      chaincode    Compiles the specified chaincode.
      help        Help about any command

    Flags:
      -h, --help[=false]: help for openchain


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

The peer command will run peer process. You can then use the other commands to interact with this peer process. For example, status will show the peer status.

Test

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

cd $GOPATH/src/github.com/openblockchain/obc-peer
go test -timeout=20m $(go list github.com/openblockchain/obc-peer/... | grep -v /vendor/)

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 name. To run tests with verbose output use the -v flag. For example, to run TestGetFoo function, change to the directory containing the foo_test.go and enter:

go test -test.v -run=TestGetFoo

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 Openchain network of several validating peers, follow the instructions on the Devnet Setup page. This network leverage Docker to manage multiple instances of validating peer 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 Openchain peer node through the available APIs and packages, follow the instructions on the API Documentation page.

Configuration

Configuration utilizes the viper and cobra libraries.

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

OPENCHAIN_PEER_LOGGING_LEVEL=CRITICAL ./obc-peer

Logging

Logging utilizes the go-logging library.

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

Generating grpc code

If you modify ant .proto files, run the following command to generate new .pb.go files.

/openchain/obc-dev-env/compile_protos.sh

Adding or updating a Go packages

Openchain uses the Go 1.5 Vendor Experiment for package management. This means that all required packages reside in the /vendor folder within the obc-peer project. This is enabled because the GO15VENDOREXPERIMENT environment variable is set to 1 in the Vagrant environment. Go will use packages in this folder instead of the GOPATH when go install or go build is run. To manage the packages in the /vendor folder, we use Govendor. This 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

Building outside of Vagrant

This is not recommended, however some users may wish to build Openchain outside of Vagrant if they use an editor with built in Go tooling. The instructions are

1. Follow all steps required to setup and run a Vagrant image.

• Make you you have Go 1.5.1 or later installed
• Set the GO15VENDOREXPERIMENT environmental variable to 1. export GO15VENDOREXPERIMENT=1
• Install RocksDB version 4.1
• Run the following commands replacing /opt/rocksdb with the path where you installed RocksDB

cd $GOPATH/src/github.com/openblockchain/obc-peer
CGO_CFLAGS="-I/opt/rocksdb/include" CGO_LDFLAGS="-L/opt/rocksdb -lrocksdb -lstdc++ -lm -lz -lbz2 -lsnappy" go install