Part 1 (February 28: 12 min) - Blockchain concepts revision (in a visual way)

Blockchain demo (using https://anders.com/blockchain/). My Brazilian Portuguese documentation about this project: Blockchain: Uma visualização gráfica.

Part 2 (February 28: 48 min) - Using geth

Shell 1

$ tmux
$ git clone https://github.com/paulojeronimo/ethereum-tutorial-cotidiano ethereum-tutorial
$ cd ethereum-tutorial
$ mkdir tmp/

Geth installation geth:

macOS:

$ brew install geth

Arch Linux:

$ sudo pacman -S geth
 
$ mkdir -p tmp/node1
$ cd tmp
$ cat ../genesis.json
$ geth --datadir node1 init ../genesis.json
$ tree node1
$ geth --datadir node1 console 2> node1.log
> admin.nodeInfo
> eth.blockNumber
> personal.newAccount()

Shell 2

$ geth attach node1/geth.ipc
> admin.nodeInfo
> eth.blockNumber

Shell 1

> miner.start(1)
> eth.mining
> eth.blockNumber
> eth.blockNumber
> eth.getBlock(eth.blockNumber).miner

Shell 2

> eth.blockNumber
> exit

Shell 1

> exit
$ geth --datadir node1 --rpc --rpcapi personal,db,eth,net,web3 --rpccorsdomain http://localhost:8000 console 2> node1.log
> eth.blockNumber
> miner.start(1)
> eth.blockNumber

Shell 2

$ git clone https://github.com/etherparty/explorer
$ (cd explorer && npm start &> ../explorer.log) &
$ tail -f explorer.log
<Ctrl+C>

Browser: http://localhost:8000

$ geth --datadir node2 init ../genesis.json
$ geth --datadir node2/ console 2> node2.log
Fatal: Error starting protocol stack: listen udp :30303: bind: address already in use
$ geth --datadir node2/ console 2> node2.log --port 30304
> admin.nodeInfo
> exit

Shell 1

> exit
$ geth --datadir node1 --rpc --rpcapi personal,db,eth,net,web3 --rpccorsdomain http://localhost:8000 --nodiscover --networkid 1234 console 2> node1.log
> admin.nodeInfo.enode
> admin.nodeInfo.protocols.eth.network

Shell 2

$ geth --datadir node2/ console --port 30304 --nodiscover --networkid 1234 2> node2.log
> admin.nodeInfo.enode
"enode://b45c61..."

Shell 1

> admin.peers
> admin.addPeer("enode://b45c61...")
> admin.peers
> admin.peers[0].id
"b45c61..."

Shell 2

> admin.peers
> admin.peers[0].id
"b1b3f1..."

Shell 1

> admin.nodeInfo.id
"b1b3f1..."
> eth.blockNumber
0
> miner.start(1)
> eth.blockNumber
2

Shell 2

> eth.blockNumber
0
> eth.syncing
{
  currentBlock: 0,
  highestBlock: 83,
  knownStates: 7,
  pulledStates: 7,
  startingBlock: 0
}
something was wrong at this point (node2.log was generating synchronization errors, so …​ let’s restart everything (excluding the block explorer)!

Shell 1

> exit
$ rm -rf node1*

Shell 2

> exit
$ rm -rf node2*
$

Shell 1

$ geth --datadir node1 init ../genesis.json
$ geth --datadir node1 --rpc --rpcapi personal,db,eth,net,web3 --rpccorsdomain http://localhost:8000 --nodiscover --networkid 1234 console 2> node1.log
> personal.newAccount()
> admin.nodeInfo.enode
"enode://b1b3f1..."

Shell 2

$ geth --datadir node2 init ../genesis.json
$ geth --datadir node2 --rpc --rpcapi personal,db,eth,net,web3 --rpccorsdomain http://localhost:8000 --nodiscover --networkid 1234 --port 30304 console 2> node2.log
> personal.newAccount()
> admin.peers
[]
> admin.addPeer("enode://b1b3f1...")

Shell 1

> admin.peers
> miner.start(1)
> eth.blockNumber

Shell 2

> eth.blockNumber
> miner.start(1)
> eth.getBlock(eth.blockNumber).miner
"0x6546b634c3dc6fda187af7cfd93a2b013baea862"
> eth.getBlock(eth.blockNumber).miner
"0xbb8b9b883e59dc48ed907785f8e27c0246b7e6a7"

Shell 1

> eth.getBalance(eth.getBlock(eth.blockNumber).miner)
1.60984375e+21
> eth.getBalance(eth.getBlock(eth.blockNumber).miner)
665937500000000000000

Part 3 (March 7: 40 min) - Solidity + browser-solidity and geth

Are you in a hurry? See this:

Part 4 (March 7: 50 min) - Solidity + web3j

Are you in a hurry? See this:

I will present a Java + web3j version of the "voting app" presented by Siraj Raval in his video "A Guide to Building Your First Decentralized Application".

Part 5 (Bonus - in my YouTube channel) - Writing a complete Java + Ethereum application from scratch

The cake cherry.

Available soon (next Wednesday: March 7) on my GitHub account and on my YouTube channel.