Download, Compile, Store

Now we will download a contract, compile it, and upload it to the Source chain.

Download

We're going to grab the cosmwasm-examples repo and compile our chosen contract.

# get the code
git clone https://github.com/CosmWasm/cosmwasm-examples
cd cosmwasm-examples
git fetch
git checkout 44d6a256cd99e66849e550185c98671d4109d78b # current at time of writing, should be cw 1.0.0-beta
cd contracts/erc20

Compile

We can compile our contract like so:

# compile the wasm contract with stable toolchain
rustup default stable
cargo wasm

However, we want to create an optimised version to limit gas usage, so we're going to run:

sudo docker run --rm -v "$(pwd)":/code \
    --mount type=volume,source="$(basename "$(pwd)")_cache",target=/code/target \
    --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
    cosmwasm/rust-optimizer:0.12.6

This will result in an artifact called cw_erc20.wasm being created in the artifacts directory.

Uploading

You can now upload, or 'store' this to the chain via your local node.

cd artifacts
sourced tx wasm store cw_erc20.wasm  --from <your-key> --chain-id=<chain-id> \
  --gas-prices 0.1usource --gas auto --gas-adjustment 1.3 -b block -y

You will need to look in the output for this command for the code ID of the contract. In the JSON, it will look like {"key":"code_id","value":"6"} in the output.

Alternatively, you can capture the output of the command run above, by doing these steps instead, and use the jq tool installed earlier to get the code_id value:

cd artifacts
TX=$(sourced tx wasm store cw_erc20.wasm  --from <your-key> --chain-id=<chain-id> --gas-prices 0.1usource --gas auto --gas-adjustment 1.3 -b block --output json -y | jq -r '.txhash')
CODE_ID=$(sourced query tx $TX --output json | jq -r '.logs[0].events[-1].attributes[0].value')

You can now see this value with:

echo $CODE_ID