The structure of this practice is as follows.

Folder	README
/contract	Solidity contract sources and binaries
/app/app.js	NodeJS main application
/app/test/*	Test for every contract
/app/test/config	Configuration file

1. Setup Enviroment

First, we need to setup our development environment.

• For Windows 7,8,10. Instructions-Win.md
• For Unix (Ubuntu 16.04). Instructions-Unix.md
• For MacOS ElCapitan and Sierra. Instructions-OSX.md

2. Run Ethereum Full Node

To configure ethereum in private network mode:

1. Create a configuration file (genesis.json)

   {
       "config": {
           "chainId": 123456780221054942,
           "homesteadBlock": 0,
           "eip155Block": 0,
           "eip158Block": 0
       },
       "difficulty": "0x20000",
       "gasLimit": "0x1DF5E70",
       "extraData": "0x6365726f6e",
       "alloc": {
       }
   }

2. Initialize ethereum blockchain with custom network and genesis id.

   $ geth --datadir data --networkid 123456780221054942 --ipcpath $ethereumpath/geth.ipc --rpc --rpcapi "eth,net,web3,admin,personal" --rpcaddr=localhost --rpcport=6545 init genesis.json

3. Run geth service with RPC api enabled

   $ geth --datadir data --networkid 123456780221054942 --ipcpath $ethereumpath/geth.ipc --rpc --rpcapi "eth,net,web3,admin,personal" --rpcaddr=localhost --rpcport=6545 console

4. Inside the geth console, create a new account, which will be the coinbase account

   > personal.newAccount('YOUR_PASSPHRASE');

   Don't forget to keep safe your passphrase

3. Deploy contract

The contract files is located in the subdirectory contract.

• contract-*.sol: The source code of contract in solidity language
• contract-*.abi: The interface definition of contract
• contract-*.bin: The bytecode of contract, used to deploy in ethereum.

Note: Where * it's a wildcard to represent the name of the contract.

1. Open new terminal tab/window and execute:

   $ geth attach

2. Start mining ethers to coinbase

   > miner.start()

   Wait to ethereum builds the DAG file and start mining.
3. Unlock your account

   > personal.unlockAccount('your coinbase address', 'your passphrase')

4. Open another terminal window and execute geth attach to deploy the contract

   > var contract = web3.eth.contract(ABI_INTERFACE);
   > var instance = contract.new({
                              from: 'your coinbase address', 
                              data: CONTRACT_BYTECODE, 
                              gas: '4700000'
                    }, function (e, c){
                          if (typeof c.address !== 'undefined') {
                              console.log('Contract mined! address: ' + c.address + ' transactionHash: ' + c.transactionHash);
                          }
                    });

5. Wait to see in the terminal something like this:

   Contract mined! address: 0xdaa24d02bad7e9d6a80106db164bad9399a0423e

   That's your contract address.
6. Repeat 1-4 steps for every contract in the folder.

Note: You can compile your code without a solidity compiler installed in your computer, in this case you can use this online web tool to get the bytecode and ABI definition: https://ethereum.github.io/browser-solidity/

4. Run NodeJS App

The nodejs application uses just web3 (https://github.com/expressjs) as webserver and Hoogan.js (http://twitter.github.io/hogan.js/) npm package for template view engine. The project is located in the subdirectory app.

1. Open a terminal window and go to app directory
2. Install the nodejs dependencies

   $ npm install -d

3. Open config.js file and replace the following lines with the coinbase address, passphrase created in the step 2.1 and contract address deployed.

   ipc: 'PATH_TO_IPC'
   ...
   coinbase: 'YOUR_FIRST_ACCOUNT_ADDRESS',
   passphrase: 'YOUR_FIRST_ACCOUNT_PASSPHRASE'

   Also you need to change the contract addresses generated in the step 3.

   contracts: {
      ...
      contract_name: {
          ...
          address: 'YOUR_COTNRACT_ADDRESS'
      }
      ...
   }

4. Run application main file

   $ nodejs app.js

   or

   $ node app.js

Note: Your ethereum node must be mining while the application is running.

FAQ

The IPC file location for every OS.

• Windows: ~/AppData/Roaming/Ethereum/geth.ipc
• MacOS: ~/Library/Ethereum/geth.ipc
• Linux: ~/.ethereum/geth.ipc

Links

• How to install command line tools in OSX: http://railsapps.github.io/xcode-command-line-tools.html
• Ethereum Wallet: https://github.com/ethereum/mist/releases/tag/v0.9.2
• Remix Solidity Compiler: https://remix.ethereum.org/
• Time converter to seconds: http://www.ruddwire.com/handy-code/date-to-millisecond-calculators/#.WglN6dvmGCR