Setup testnet Ethereum network with Docker
Ethereum is a decentralized platform that runs smart contracts: applications that run exactly as programmed without any possibility of downtime, censorship, fraud or third party interference.
This is step-by-step guide, how to setup testnet Ethereum network.
We'll setup ethereum testnet node in the docker container and write ruby json-rpc client. The difference between ethereum(Frontier) and testnet ethereum(Ropsten) networks is that the testnet used for development. The genesis block on the testnet was set with a very low difficulty so anyone can do minning. The coins mained in the testnet have no values. You can request some coins on the facuet or trying to mine it.
I assume you have got hand-on experience with Docker, also you’re knowing Ruby a little.
You can ask why docker? I don't want to install
gethlocally.
Copy the source code from my Github repository.
Let's get stated from the Docker container, here is a Dockerfile which we'll use:
FROM ubuntu:16.04
LABEL version="1.0"
LABEL maintainer="[email protected]"
ENV DEBIAN_FRONTEND=noninteractive
RUN apt-get update && apt-get install --yes software-properties-common
RUN add-apt-repository ppa:ethereum/ethereum
RUN apt-get update && apt-get install --yes geth
RUN adduser --disabled-login --gecos "" eth_user
USER eth_user
WORKDIR /home/eth_user
ENTRYPOINT bash
Now build an image:
docker build -t ether_node .
# Output omitted
# ...
After the building process, let's start it:
docker run --rm -it -p 8545:8545 ether_node
# Output omitted
# ...
Now we need to start our node to use testnet.
From the docker container:
[email protected]:~$ geth --rpc --rpcaddr="0.0.0.0" --testnet --fast --cache=512 console
WARN [xx-xx|xx:xx:xx] No etherbase set and no accounts found as default
INFO [xx-xx|xx:xx:xx] Starting peer-to-peer node instance=Geth/v1.7.2-stable-1db4ecdc/linux-amd64/go1.9
INFO [xx-xx|xx:xx:xx] Allocated cache and file handles database=/home/eth_user/.ethereum/testnet/geth/chaindata cache=512 handles=1024
INFO [xx-xx|xx:xx:xx] Initialised chain configuration config="{ChainID: 3 Homestead: 0 DAO: <nil> DAOSupport: true EIP150: 0 EIP155: 10 EIP158: 10 Byzantium: 1700000 Engine: ethash}"
INFO [xx-xx|xx:xx:xx] Disk storage enabled for ethash caches dir=/home/eth_user/.ethereum/testnet/geth/ethash count=3
INFO [xx-xx|xx:xx:xx] Disk storage enabled for ethash DAGs dir=/home/eth_user/.ethash count=2
INFO [xx-xx|xx:xx:xx] Initialising Ethereum protocol versions="[63 62]" network=3
INFO [xx-xx|xx:xx:xx] Loaded most recent local header number=1934866 hash=480bc8…021ca1 td=6358565226576368
INFO [xx-xx|xx:xx:xx] Loaded most recent local full block number=1934867 hash=a61065…492947 td=6358586381670544
INFO [xx-xx|xx:xx:xx] Loaded most recent local fast block number=1934866 hash=480bc8…021ca1 td=6358565226576368
INFO [xx-xx|xx:xx:xx] Loaded local transaction journal transactions=0 dropped=0
INFO [xx-xx|xx:xx:xx] Regenerated local transaction journal transactions=0 accounts=0
WARN [xx-xx|xx:xx:xx] Blockchain not empty, fast sync disabled
# ....
Note about geth command line options:
--rpc- enable RPC--rpcaddr="0.0.0.0"- HTTP-RPC server listening interface (default: "localhost")--testnet- Ropsten network: pre-configured test network--fast- Enable fast syncing through state downloads--cache=512- Megabytes of memory allocated to internal cachingconsole- Start an interactive JavaScript environment
Documentation for all other command line options you can find here
The next step is the database synchronization. That process can be long. In my case I was waiting at least 5 hours before got the last block.
As long as you see in the logs INFO [00-00|XX:XX:XX] Imported new state entries .... the network is syncing.
To get rid of annoying log entries like INFO ....., stop syncing and start again with --verbosity=2 options.
[email protected]:~$ geth --rpc --rpcaddr="0.0.0.0" --testnet --fast --cache=512 --verbosity=2 console
WARN [xx-xx|xx:xx:xx] No etherbase set and no accounts found as default
WARN [xx-xx|xx:xx:xx] Blockchain not empty, fast sync disabled
Welcome to the Geth JavaScript console!
instance: Geth/v1.7.2-stable-1db4ecdc/linux-amd64/go1.9
modules: admin:1.0 debug:1.0 eth:1.0 miner:1.0 net:1.0 personal:1.0 rpc:1.0 txpool:1.0 web3:1.0
>
You can check progress with command eth.syncing, if syncing is on going you must see:
{
"currentBlock": 1032920,
"highestBlock": 1934940,
"knownStates": 8621554,
"pulledStates": 8618011,
"startingBlock": 3926371
}
Your actual output must be differ. Check last block here ropsten.etherscan.io.
If you're lucky guy and your waiting is complete, you'll see INFO [xx-xx|xx:xx:xx] Imported new chain segment ... entries in the log.
The command eth.syncing retruns false and command eth.blockNumber returns the same block number as on ropsten.etherscan.io (+- 2 or 3 blocks).
Now let's create a brand new address and sent to it some of ether from faucet.
In order to create a new account we'll use geth console and the personal_newAccount() method.
> personal.newAccount("foo")
"0xd46c9fb0447dabc0d862141e817039fedbb653b0"
>
With the new account send to it some ether by faucet. In my case I'm using this faucet.
We'll check the account balance with JSON-RPC client written by Ruby language (from the json_rpc_client folder):
You might need to install script dependencies, check out the README.md file.
$> ruby client.rb "0xd46c9fb0447dabc0d862141e817039fedbb653b0"
Address: 0xd46c9fb0447dabc0d862141e817039fedbb653b0 balance: 0
Sleep 3 second ...
Address: 0xd46c9fb0447dabc0d862141e817039fedbb653b0 balance: 0
Sleep 3 second ...
Address: 0xd46c9fb0447dabc0d862141e817039fedbb653b0 balance: 0
Sleep 3 second ...
Address: 0xd46c9fb0447dabc0d862141e817039fedbb653b0 balance: 3
Cheers! The account is filled with 3 ether. You also can check the account balance here ropsten etherscan.
We have got up and running docker container with Ethereum testnet network (AKA Ropsten) and we able to communicate with our node by JSON-RPC client written by Ruby. It's a good start to create your own blockchain project based on Ethereum.
References: