Installing the development environment

Follow these instructions to obtain the Hyperledger Composer development tools (primarily used to create Business Networks) and stand up a Hyperledger Fabric (primarily used to run/deploy your Business Networks locally). Note that the Business Networks you create can also be deployed to Hyperledger Fabric runtimes in other environments e.g. on a cloud platform.

Before you begin

Make sure you have installed the required pre-requisites, following the instructions in Installing pre-requisites.

These instructions assume that you've not installed the tools and used them before. If this is not the case, you might want to check that your previous setup is completely destroyed before you start following this guide. To learn how to do this, skip to the Appendix.

To provide flexibility and enable the maximum number of dev, test and deployment scenarios, Composer is delivered as a set of components you can install with npm and control from the CLI. These instructions will tell you how to install everything first, then how to control your development environment.

Installing components

Step 1: Install the CLI tools

There are a few useful CLI tools for Composer developers. The most important one is composer-cli, which contains all the essential operations, so we'll install that first. Next, we'll also pick up generator-hyperledger-composer, composer-rest-server and Yeoman plus the generator-hyperledger-composer. Those last 3 are not core parts of the development environment, but they'll be useful if you're following the tutorials or developing applications that interact with your Business Network, so we'll get them installed now.

Note that you should not use su or sudo for the following npm commands.

Essential CLI tools:
```
npm install -g composer-cli@0.19
```
Utility for running a REST Server on your machine to expose your business networks as RESTful APIs:
```
npm install -g composer-rest-server@0.19
```

Useful utility for generating application assets:

npm install -g generator-hyperledger-composer@0.19

Yeoman is a tool for generating applications, which utilises generator-hyperledger-composer:
```
npm install -g yo
```

Step 2: Install Playground

If you've already tried Composer online, you'll have seen the browser app "Playground". You can run this locally on your development machine too, giving you a UI for viewing and demonstrating your business networks.

Browser app for simple editing and testing Business Networks:
```
npm install -g composer-playground@0.19
```

Step 3: Set up your IDE

Whilst the browser app can be used to work on your Business Network code, most users will prefer to work in an IDE. Our favourite is VSCode, because a Composer extension is available.

Install VSCode from this URL: https://code.visualstudio.com/download
Open VSCode, go to Extensions, then search for and install the Hyperledger Composer extension from the Marketplace.

Step 4: Install Hyperledger Fabric

This step gives you a local Hyperledger Fabric runtime to deploy your business networks to.

In a directory of your choice (we will assume ~/fabric-dev-servers), get the .tar.gz file that contains the tools to install Hyperledger Fabric:
```
mkdir ~/fabric-dev-servers && cd ~/fabric-dev-servers

curl -O https://raw.githubusercontent.com/hyperledger/composer-tools/master/packages/fabric-dev-servers/fabric-dev-servers.tar.gz
tar -xvf fabric-dev-servers.tar.gz
```
A zip is also available if you prefer: just replace the .tar.gz file with fabric-dev-servers.zip and the tar -xvf command with a unzip command in the preceding snippet.
Use the scripts you just downloaded and extracted to download a local Hyperledger Fabric v1.1 runtime:
```
cd ~/fabric-dev-servers
export FABRIC_VERSION=hlfv11
./downloadFabric.sh
```

Congratulations, you've now installed everything required for the typical Developer Environment. Read on to learn some of the most common things you'll do with this environment to develop and test your Blockchain Business Networks.

Controlling your dev environment

Starting and stopping Hyperledger Fabric

You control your runtime using a set of scripts which you'll find in ~/fabric-dev-servers if you followed the suggested defaults.

The first time you start up a new runtime, you'll need to run the start script, then generate a PeerAdmin card:

    cd ~/fabric-dev-servers
    export FABRIC_VERSION=hlfv11
    ./startFabric.sh
    ./createPeerAdminCard.sh

You can start and stop your runtime using ~/fabric-dev-servers/stopFabric.sh, and start it again with ~/fabric-dev-servers/startFabric.sh.

At the end of your development session, you run ~/fabric-dev-servers/stopFabric.sh and then ~/fabric-dev-servers/teardownFabric.sh. Note that if you've run the teardown script, the next time you start the runtime, you'll need to create a new PeerAdmin card just like you did on first time startup.

The local runtime is intended to be frequently started, stopped and torn down, for development use. If you're looking for a runtime with more persistent state, you'll want to run one outside of the dev environment, and deploy Business Networks to it. Examples of this include running it via Kubernetes, or on a managed platform such as IBM Cloud.

Start the web app ("Playground")

To start the web app, run:

    composer-playground

It will typically open your browser automatically, at the following address: http://localhost:8080/login

You should see the PeerAdmin@hlfv1 Card you created with the createPeerAdminCard script on your "My Business Networks" screen in the web app: if you don't see this, you may not have correctly started up your runtime!

Congratulations, you've got all the components running, and you also know how to stop and tear them down when you're done with your dev session.

What Next?

Learn how to use the web app UI with the Playground Tutorial
Learn how to use the CLI and VSCode tools with the Developer Tutorial

Appendix: destroy a previous setup

If you've previously used an older version of Hyperledger Composer and are now setting up a new install, you may want to kill and remove all previous Docker containers, which you can do with these commands:

    docker kill $(docker ps -q)
    docker rm $(docker ps -aq)
    docker rmi $(docker images dev-* -q)