Alpha Casper FFG Testnet Instructions

Welcome to the first release of the alpha Casper FFG testnet, built on pyethereum. This network represents the result of years of work on cryptoeconomic proof-of-stake and months of active development of the client, and is a fully-featured and usable network, allowing users to send transactions, mine and become validators. However, this is still several steps away from a network that will be ready for launch. Some parameters are set differently from the intended final settings, and the currently only available client, pyethereum, has a much lower processing capacity than clients implemented in faster languages; as a result, network parameters will be heavily restricted to ensure network sustainability. Do not expect performance equivalent to test networks operated by more performant clients such as Geth and Parity.

What is Casper FFG and how does it work?

This is out of scope of this document, but you can find info in these links:

The rest of this document assumes some familiarity with Casper FFG.

Just taking a look

If you want to go straight to running a node, feel free to skip straight to the next section ("Running a Node")

Look at the ethstats page here: http://34.203.42.208:3000/

Also, you can use web3 (installation: sudo pip3 install web3) to connect to a node as follows (assuming python 3):

> from web3 import Web3, HTTPProvider
> web3 = Web3(HTTPProvider('http://52.87.179.32:8545'))
> web3.eth.getBlock('latest')
# This should return the head of the chain

Then:

> import urllib.request, json
> 


# This may take a while depending on your internet connection
> casper_abi = json.load(urllib.request.urlopen( "https://gist.githubusercontent.com/vbuterin/868a6213b058fb4f1fdfcf64e54f0e91/raw/33fc177da3863ec320d1ebf95816ba52ffbffbe8/casper_abi"))
> casper = web3.eth.contract(abi=casper_abi, address='0xbd832b0cd3291c39ef67691858f35c71dfb3bf21').call()

# This should return the current epoch
> casper.get_current_epoch()

Look through the Casper contract to see all the functions that you can call. Any public variable has a corresponding getter method, eg. a variable x, if it's public, has the corresponding getter get_x(); see the Vyper documentation here (the latest available info) or here (this is outdated as of April 2 2018) for a more complete description on what getters are available.

Running a node

To run a node, follow the following instructions to download and run a Docker instance:

Installing docker (if you do not yet have it) on Ubuntu:

curl -fsSL get.docker.com -o get-docker.sh
sudo sh get-docker.sh
sudo usermod -aG docker $USER

(Replace $USER with your username, i.e. the one you see in login, in the terminal, in your file directory, etc.) Make sure to log out and log back in after this step.

On MacOS, follow the instructions here: https://docs.docker.com/docker-for-mac/install/#install-and-run-docker-for-mac

Getting the docker containers for the testnet nodes (warning, this involves a few hundred MB of downloading)

$ git clone http://github.com/karlfloersch/docker-pyeth-dev
$ cd docker-pyeth-dev
$ sudo make new-account
🌟 Creating keystore directory at ./validator/data/config/keystore
🌟 Enter a new password to encrypt your account:
🌟 Your password is stored at ./validator/data/config/password.txt
🌟 Pyethapp container is creating new address for you, might take few seconds:

Running:

$ sudo make run-node bootstrap_node=enode://d3260a710a752b926bb3328ebe29bfb568e4fb3b4c7ff59450738661113fb21f5efbdf42904c706a9f152275890840345a5bc990745919eeb2dfc2c481d778ee@54.167.247.63:30303

If that enode does not work, try replacing with: enode://a120401858c93f0be73ae7765930174689cad026df332f7e06a047ead917cee193e9210e899c3143cce55dd991493227ecea15de42aa05b9b730d2189e19b567@52.87.179.32:30303

Also, if you have a Geth, Parity or Akasha client or other service already using the port 30303, try changing it to something else, e.g. 30304.

If you are running a node, then you can use web3.py to connect to it:

$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                            NAMES
20a0dfe1d9e2        casper-validator    "sh /root/start.sh p…"   18 minutes ago      Up 18 minutes       8545/tcp, 30303/tcp, 30303/udp   validator
$ docker exec -it 20a0dfe1d9e2 python

Replace 20a0dfe1d9e2 with whatever container ID appears in the output when you run docker ps. Then repeat the web3 instructions above inside the python console that appears, but use Web3(HTTPProvider('http://localhost:8545')) in place of the remote node.

To mine:

$ sudo make run-node mine_percent=90 bootstrap_node=enode://d3260a710a752b926bb3328ebe29bfb568e4fb3b4c7ff59450738661113fb21f5efbdf42904c706a9f152275890840345a5bc990745919eeb2dfc2c481d778ee@54.167.247.63:30303

If you get an error like this:

docker: Error response from daemon: Conflict. The container name "/validator" is already in use...

Then, you can fix by running sudo docker rm validator.

Running a validator

First, you will need to have enough testnet ETH to become a validator. You can either mine a lot of blocks, or ask us for ETH (a faucet may be available soon).

To ask for ETH, you will need to have an ETH address. You can either use a keystore file you already generated on your own, e.g. using geth or pyeth_keys, or generate one with the docker tools.

To login as a validator with the account you generated by running the sudo make new-account command above, run:

make run-node validate=true deposit=2000 bootstrap_node=enode://d3260a710a752b926bb3328ebe29bfb568e4fb3b4c7ff59450738661113fb21f5efbdf42904c706a9f152275890840345a5bc990745919eeb2dfc2c481d778ee@54.167.247.63:30303

Replacing 2000 with whatever amount of ETH you want to deposit (min 1500).

From there, just leave the docker node running. Note that once you log on, it will take ~1.5 dynasties (normally, ~30 minutes) until you are in the active validator set and can start voting.

Checking your status

Aside from the web3 route, you can also play around with the node directly through the python console. Press Ctrl+C inside of it, and you will see an instruction like Hit [ENTER], to launch console; [Ctrl+C] again to quit! [0s]. Press Ctrl+C again and you will enter the console.

From there, you can use eth.chain to access the pyethereum Chain object (see documentation here). Use eth.services.accounts.accounts[0].address to get your validator's address, which is also used as a kind of ID for the validator. You can also create a python object that will let you call commands of the Casper contract as so:

>> import urllib.request, json
>> casper_abi = casper_abi = json.load(urllib.request.urlopen( "https://gist.githubusercontent.com/vbuterin/868a6213b058fb4f1fdfcf64e54f0e91/raw/33fc177da3863ec320d1ebf95816ba52ffbffbe8/casper_abi"))
>> from ethereum.tools import tester
>> casper = tester.ABIContract(tester.State(eth.chain.state), casper_abi, '0xbd832b0cd3291c39ef67691858f35c71dfb3bf21')
>> casper.get_current_epoch()
# This should return the current epoch number

To get data about yourself, do:

>> my_index = casper.get_validator_indexes(eth.services.accounts.accounts[0].address)
>> 
# This should return your current deposit size
>> casper.get_deposit_size(my_index)
>> 
# This should return the current dynasty, and your validator's start and end dynasty
>> casper.get_dynasty(), casper.get_validators__start_dynasty(my_index), casper.get_validators__end_dynasty(my_index)

Note that you will need to re-run the casper = tester.ABIContract... line in order to call Casper with the most recent state.

To broadcast a transaction, use eth.app.services.chain.broadcast_transaction(tx)

To exit pyethapp, type Ctrl+D.

Logging out

You can log out with the command:

make run-node validate=true logout=true bootstrap_node=enode://d3260a710a752b926bb3328ebe29bfb568e4fb3b4c7ff59450738661113fb21f5efbdf42904c706a9f152275890840345a5bc990745919eeb2dfc2c481d778ee@54.167.247.63:30303

Then just leave the validator running, and after the withdrawal period ends it will automatically send another transaction to withdraw you.

Note that in general, staying online is important. You as a validator will only be profitable if you are online more than half the time in the normal case, and if many other validators are offline than you may need to be online almost all of the time in order not to incur a loss.