Setting up a local simnet

Learn how to run your own local "simnet" node.

Prerequisites

Make sure you have the required hardware and dependencies installed. Follow this guide if you haven't already.

Setting up a local simnet

For local development and testing, we can configure a local "simnet", or a fake network on our local computer.

The easiest way to do so is with our melsimnet binary. In the melnode directory:

cargo run --bin melsimnet -- create -s 1. -s 2. -s 3. -s 4.

Running this command will generate several (4 in this case) files and scripts to run the staker nodes in your custom local network. This means that staker 1 will have voting power equivalent to 1 SYM and staker 2 will have 2 SYM, etc.

Let's go through what this all means:

1. run-staker-*.sh - run an individual staker node

2. run-all.sh - run all of the staker nodes on a custom local network

3. staker-*.yaml* - defines the config for an individual staker node (explained below)

4. genesis.yaml - defines the genesis config for the custom local network (explained below)

After running some (or all) of the nodes, you'll be able to interact with the nodes via melwallet-client, melminter, or even direct HTTP calls.

./run-all.sh

Should produce logs like:

[2024-05-11T14:28:09Z INFO  melnode] melnode v0.20.7 initializing...
[2024-05-11T14:28:09Z DEBUG melnode::storage::storage] about to sqlite
[2024-05-11T14:28:09Z DEBUG melnode::storage::storage] sqlite initted
[2024-05-11T14:28:09Z DEBUG melnode::storage::storage] about to mesha
[2024-05-11T14:28:09Z DEBUG melnode::args] node storage opened
[2024-05-11T14:28:09Z INFO  melnode] bootstrapping with [127.0.0.1:2000]
[2024-05-11T14:28:09Z DEBUG melnode::node] starting to listen at 127.0.0.1:2000
[2024-05-11T14:28:19Z DEBUG melnode::staker] starting consensus for 1...
[2024-05-11T14:28:19Z WARN  melnode::staker] mempool not at the right height, trying again
[2024-05-11T14:28:29Z DEBUG melnode::staker] starting consensus for 1...
[2024-05-11T14:28:29Z DEBUG melstf::state] changing fee multiplier 100 by 1
[2024-05-11T14:28:29Z DEBUG melnode::staker] proposed state has 0 transactions
[2024-05-11T14:28:32Z DEBUG melnode::staker] 1/127.0.0.1:5000 DECIDED on a block with 240 bytes within 3.155822014s
[2024-05-11T14:28:32Z DEBUG melstf::state] applied a batch of 0 txx to #<c99d36b369d0fc1bd494b84db635c5964e8359fafff00a1732d19090c3595e41> => #<c99d36b369d0fc1bd494b84db635c5964e8359fafff00a1732d19090c3595e41>
[2024-05-11T14:28:32Z DEBUG melstf::state] changing fee multiplier 100 by 1
[2024-05-11T14:28:32Z DEBUG melnode::storage::storage] applied block 1 / 64e3f33aa793f118ef09fa8aa72a7f6b7b5831dba1f8052d8ac1506e04883a09 in 5.01ms (history insertion 2.42ms)
[2024-05-11T14:28:32Z DEBUG melnode::staker] 1/127.0.0.1:5000 COMMITTED the newly decided block within 3.164806678s

melwallet-cli, melminter

To use melwallet or melminter on your local simnet, first set the MELBOOTSTRAP environment variable to a hard-coded block height and header hash to bootstrap clients on this network:

export MELBOOTSTRAP=<network-name>:<block-height>:<header-hash>

You can find all the information needed from the node logs. From the logs above, you can set:

export MELBOOTSTRAP=custom02:1:64e3f33aa793f118ef09fa8aa72a7f6b7b5831dba1f8052d8ac1506e04883a09

To use the wallet, run melwallet-cli with the --bootstrap flag to specify the socket address for connecting to the local node:

melwallet-cli --wallet-path my-wallet.json --bootstrap 127.0.0.1:2000 create --network custom02

Similarly with melminter:

melminter --bootstrap 127.0.0.1:2000 --payout <wallet-address>

Local simnets all support faucet transactions:

melwallet-cli --wallet-path my-wallet.json --bootstrap 127.0.0.1:2000 send-faucet --wait

Custom genesis configuration

This is only needed to start our own custom network, melnode accepts a YAML config file similar to the following:

network: custom02 # anything from custom02..custom08
# specifies the "initial stash" of money in the genesis block
init_coindata:
  # what address gets the initial supply of money
  covhash: t5xw3qvzvfezkb748d3zt929zkbt7szgt6jr3zfxxnewj1rtajpjx0
  # how many units (in millionths)
  value: 1000000
  # denomination
  denom: MEL
  # additional data in the UTXO, as a hex string
  additional_data: ""
# specifies all the stakers with consensus power.
# we need to specify ourselves in order to produce any blocks; "Mel-crypttool generate-ed25519" (install via cargo) can generate a keypair for us
stakes:
  deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef:
    pubkey: 4ce983d241f1d40b0e5b65e0bd1a6877a35acaec5182f110810f1276103c829e
    e_start: 0
    e_post_end: 100000 # essentially never end the stake
    syms_staked: 10000 # does not matter
# Initial fee pool
init_fee_pool: 10000

Custom staker configuration

If we want to run a local custom staker node, melnode accepts a YAML config file:

# secret key; must correspond to "stakes.dead[...]beef.pubkey" in the network config
signing_secret: 5b4c8873cbdb089439d025e9fa817b1df1128231699131c245c0027be880d4d44ce983d241f1d40b0e5b65e0bd1a6877a35acaec5182f110810f1276103c829e
# address for staker-network communication, this can be arbitrary
listen: 127.0.0.1:20000
# must be same as "listen"
bootstrap: 127.0.0.1:20000
# where block rewards are sent
payout_addr: t5xw3qvzvfezkb748d3zt929zkbt7szgt6jr3zfxxnewj1rtajpjx0
# vote for this fee multiplier (higher values charge more fees)
target_fee_multiplier: 10000