Bash script that sets up a private Ethereum network for development and testing.
This bash script uses:
To bring up a test network, run the testnet.bash script from the root of this
repository as follows:
mkdir -p testnet
TESTNET_BASE_DIR=testnet/ ./testnet.bashYou can run the same command to restart the testnet after shutting it down using CTRL+C.
All the account passwords (by default) are peppercat.
Suggest you just copy the testnet.bash script over to your repo, modify it to suit your needs, and
use it there. Would appreciate attribution (by linking to this repo).
Accepts inputs through environment variables:
Directory in which all data is stored. This is where you will find your node data directories, dag directories, and more.
If this is not set, will create a temporary directory in which to store all data.
Set this environment variable to specify a path to a custom geth. If not set, will use the first
geth available in your $PATH.
To add testnet bash as new network:
brownie networks add Ethereum ethereum-local-testnet name="Moonstream Ethereum testnet" host="http://127.0.0.1:8545" chainid=1337Just copy the bash script and edit it, my friend.
Why not Ganache?
testnet.bash is the testing environment we use to test
Moonstream crawlers and data providers.
Ganache is built for smart contract developers. In addition to smart contracts, we also need to test
blockchain (and transaction pool) crawlers and data providers. Our crawlers and data providers use
geth-specific APIs that Ganache either does not implement or for which the Ganache semantics differ
from the geth semantics.
Since our testnet needs to include geth nodes, Ganache is not suitable to our needs.
Moreover, Ganache feels pretty heavy-duty to me and we wanted something light-weight that we could use to spin up a private network, set up a scenario, and then run a series of tests. On our local machines or in continuous integration environments (we use GitHub Actions).
Because bash is ubiquitous, especially in continuous integration environments.
I have experimented in the past with similar setups in docker-compose (link).
This bash script does the job just as well, is much simpler to understand, and is much easier to
customize.
Copy the bash script and edit the definition of the GENESIS_JSON variable.
The vanilla script sets up 2 mining nodes. Any less and chain data will not be persisted to disk
between runs. If you wanted to add a third node, you would modify the bash script to add a run_miner
call:
MINER_0=$(run_miner 0)
MINER_1=$(run_miner 1)
MINER_2=$(run_miner 2)If you wanted to print metadata about this new miner, you would add a new echo statement near
where the miner metadata is printed:
echo "Running testnet. Miner info:"
echo "$MINER_0" | jq .
echo "$MINER_1" | jq .
echo "$MINER_2" | jq .
echo
echo "Press CTRL+C to exit."Finally, you would probably want to add the new miner's logs to the tail command:
tail -f $(echo "$MINER_0" | jq -r ".logfile") $(echo "$MINER_1" | jq -r ".logfile")Because geth is what we use in moonstream.
If you would like to add support for another Ethereum client, I would welcome a pull request.
This script uses mktemp -d when you don't specify a testnet directory.
The BSD version of mktemp has a different signature than the GNU version. Relevant StackExchange
thread: https://unix.stackexchange.com/questions/30091/fix-or-alternative-for-mktemp-in-os-x
If you want to run this script on a Mac with a temporary base directory, please let me know and I will add support. At that time, I would appreciate your help in testing the change.
In the meantime, you can get around the issue by explicitly creating a base directory and setting it
as the TESTNET_BASE_DIR environment variable.
So far, it has been tested on:
- Debian Buster VM image on WSL2 (Windows 10), bash
5.0.3(1)-release
If you have run this script successfully, I would appreciate it if you submit an edit to this README describing your environment. Thank you.
Your contributions are welcome: