The following is a list of dependencies and recommended tools that you should install in order to develop chaincode.
- Git
- Git Desktop (for those uncomfortable with git's CLI)
Git is a great version control tool to familiarize yourself with, both for chaincode development and software development in general. Also, git bash, which is installed with git on Windows, is an excellent alternative to the the Windows command prompt.
After following the installation instructions above, you can verify that git is installed using the following command:
$ git --version
git version 2.11.1.windows.1
Once you have git installed, go create an account for yourself on GitHub. The IBM Blockchain service on Bluemix currently requires that chaincode be in a GitHub repository in order to be deployed through the REST API.
The Go installation installs a set of Go CLI tools which are very useful when writing chaincode.
For example, the go build command allows you to check that your chaincode actually compiles before you attempt to deploy it to a network.
At time of writing, this chaincode is known to build successfully with version 1.7.5.
You can verify that Go is installed properly by running the following commands. Of course, the output of go version may change depending on your operating system.
$ go version
go version go1.7.5 windows/amd64
$ echo $GOPATH
C:\gopath
Your GOPATH does not need to match the one above.
It only matters that you have this variable set to a valid directory on your filesystem.
The installation instructions linked above will take you through the setup of this environment variable.
Next verify you can build GoLang code with the hello world example.
Any piece of chaincode that you write will need to import the chaincode shim from Hyperledger fabric in order to be able to read and write data to/from the ledger. In order to compile chaincode locally, which you will be doing a lot, you will need to have the fabric code present in your GOPATH. Follow the instructions below.
A few different releases of the fabric are linked above. The release you clone needs to match the Hyperledger network you are using.
For example, if you are using the Bluemix Blockchain Service then check the commit level of the Hyperledger Fabric being used by your network. It can be found in the Release Notes section of the network's UI.
Update 5/1/2017
If you are on Windows please use this commit instead: 0616a9ddc02cc541409c9d77c8b7e97523a8b96e. Windows needs a Fabric fix that disables pkcs11 that was not avaible until April 1st, 2017 (no joking). Other OSes should be able to use the same version in their release note.
Make sure that the fabric release you choose is stored under $GOPATH/src/github.com/hyperledger/fabric.
The instructions below should take you through the process of properly installing the v1.0 release on your GOPATH.
# Create the parent directories on your GOPATH
mkdir -p $GOPATH/src/github.com/hyperledger
cd $GOPATH/src/github.com/hyperledger
# Clone the appropriate release codebase into $GOPATH/src/github.com/hyperledger/fabric
# This starts at the master branch
git clone https://github.com/hyperledger/fabric.git
# Match this version to the commit level of your network (1st 7 characters will work)
cd fabric
git checkout 14055d7
# Confirm the level using git branch, should show the commit level matching your network
git branch
Open a command prompt/terminal and browse to this directory $GOPATH/src/github.com/hyperledger/fabric/examples/chaincode/go/chaincode_example02
$ go build -tags nopkcs11 .
It should return with no errors/warnings.
Download the latest Node.js LTS version.
Node.js is NOT necessary to develop chaincode, but is to run Marbles.
Open a command prompt/terminal and make sure the following commands work on your machine:
$ node -v
v6.10.1
$ npm -v
3.10.10
Visual Studio Code is a free IDE that supports all the languages in Marbles such as JS/CSS/HTML/GoLang.
Like VS Code, Atom has plugins to support any of the languages needed to develop chaincode or modify our examples.