Setup a Local Testnet (advanced)

How to setup a local Elrond Testnet on a workstation.

Prerequisites

First, clone elrond-go and elrond-proxy-go in a directory of your choice.

$ mkdir mytestnet && cd mytestnet
$ git clone git@github.com:ElrondNetwork/elrond-go.git
$ git clone git@github.com:ElrondNetwork/elrond-proxy-go.git

Then, run the prerequisites command.

$ cd elrond-go/scripts/testnet
$ ./prerequisites.sh

This will install some packages and also clone the elrond-deploy-go repository, as a sibling of the previously cloned elrond-go.

Depending on your Linux distribution, you may need to run the following commands as well:

sudo apt install tmux
sudo apt install gnome-terminal

Configure the Testnet

The variables that dictate the structure of the Testnet are located in the file scripts/testnet/variables.sh. For example:

export TESTNETDIR="$HOME/Elrond/testnet"
export SHARDCOUNT=2
...

You can override the default variables by creating a new file called local.sh, as a sibling of variables.sh. For example, in order to use a different directory than the default one:

local.sh
export TESTNETDIR="$HOME/Desktop/mytestnet/sandbox"
export USETMUX=1
export NODETERMUI=0

Once ready with overriding the desired parameters, run the config command.

$ ./config.sh

After that, you can inspect the generated configuration files in the specified folder:

$HOME/Desktop/mytestnet/sandbox
├── filegen
│   ├── filegen
│   └── output
│   ├── delegationWalletKey.pem
│   ├── delegators.pem
│   ├── genesis.json
│   ├── genesisSmartContracts.json
│   ├── nodesSetup.json
│   ├── validatorKey.pem
│   └── walletKey.pem
├── node
│   └── config
│   ├── api.toml
│   ├── config_observer.toml
│   ├── config_validator.toml
│   ├── delegationWalletKey.pem
│   ├── delegators.pem
│   ├── economics.toml
│   ├── external.toml
│   ├── gasSchedule.toml
│   ├── genesisContracts
│   │   ├── delegation.wasm
│   │   └── dns.wasm
│   ├── genesis.json
│   ├── genesisSmartContracts.json
│   ├── nodesSetup.json
│   ├── p2p.toml
│   ├── prefs.toml
│   ├── ratings.toml
│   ├── systemSmartContractsConfig.toml
│   ├── validatorKey.pem
│   └── walletKey.pem
├── node_working_dirs
├── proxy
│   └── config
│   ├── config.toml
│   ├── economics.toml
│   ├── external.toml
│   └── walletKey.pem
└── seednode
└── config
├── config.toml
└── p2p.toml

Starting and stopping the Testnet

In order to start the Testnet, run the start command.

$ ./start.sh debug

After waiting about 1 minute, you can inspect the logs of the running nodes in folder mytestnet/sandbox/node_working_dirs.

In order to stop the Testnet, run the stop command.

$ ./stop.sh

If desired, you can also pause and resume the Testnet (without actually stopping the running nodes):

$ ./pause.sh
$ ./resume.sh

Recreating the Testnet

In order to destroy the Testnet, run the clean command:

./stop.sh
./clean.sh

After running clean, you need to run config before start, in order to start the Testnet again.

If you need to recreate a Testnet from scratch, use the reset command (which also executes clean under the hood):

$ ./reset.sh

Inspecting the Proxy

By default, the local Testnet also includes a local Elrond Proxy instance, listening on port 7950. You can query in in a browser or directly in the command line. Also see REST API.

$ curl http://localhost:7950/network/config

Given the request above, extract and save the fields erd_chain_id and erd_min_transaction_version from the response. You will need them in order to send transactions against your local Testnet.

Configuring erdpy

You can configure erdpy to point to your local Testnet by default:

$ erdpy config set chainID 15...
$ erdpy config set txVersion 123
$ erdpy config set proxy http://localhost:7950

Sending transactions

Let's send a simple transaction using erdpy:

$ erdpy tx new --recall-nonce --data="Hello, World" --gas-limit=70000 \
--receiver=erd1... \
--pem=./sandbox/node/config/walletKey.pem --pem-index=0 \
--send

You should see the prepared transaction and the transaction hash in the stdout (or in the --outfile of your choice). Using the transaction hash, you can query the status of the transaction against the Proxy:

$ curl http://localhost:7950/transaction/1363...

Deploying and interacting with Smart Contracts

Let's deploy a Smart Contract using erdpy. We'll use the Simple Counter as an example.

Deploy
erdpy --verbose contract deploy --bytecode=./mycounter/output/counter.wasm \
--recall-nonce --gas-limit=5000000 \
--pem=./sandbox/node/config/walletKey.pem --pem-index=0 \
--outfile=myCounter.json \
--send

Upon deployment, you can check the status of the transaction and the existence of the Smart Contract:

$ curl http://localhost:7950/transaction/daf2...
$ curl http://localhost:7950/address/erd1qqqqqqqqqqqqqpgql...

If everything is fine (transaction status is executed and the code property of the address is set), you can interact with or perform queries against the deployed contract:

Call
erdpy --verbose contract call erd1qqqqqqqqqqqqqpgql... \
--recall-nonce --gas-limit=1000000 --function=increment \
--pem=./sandbox/node/config/walletKey.pem --pem-index=0 --outfile=myCall.json \
--send
Query
erdpy --verbose contract query erd1qqqqqqqqqqqqqpgqlq... --function=get