Part 2: Setting up Development Environment for CosmWasm

Part 1: Introduction to CosmWasm

Introduction

CosmWasm is a smart contract platform built for the Cosmos ecosystem, allowing developers to write secure and efficient smart contracts in Rust. Please check the article for basic understanding of CosmWasm. In this article, we will go through the process of setting up a development environment for CosmWasm, including the installation of essential tools and dependencies, more specifically, for CosmWasm testnet malaga-420.

Prerequisites

• A Linux-based operating system (Ubuntu is used in this article)
• Basic understanding of Bash scripting and the command line

Step 1: Update and Install Basic Dependencies

First, update the package list and install basic dependencies, including Git, wget, curl, nano, and jq:

apt-get -y update
apt-get -y install git wget curl nano jq

Step 2: Install Make

Make is a build automation tool, and it’s required for compiling some of the tools used in this tutorial. Install Make by installing the build-essential package:

apt-get -y install build-essential

Step 3: Install Go

The Go programming language is required for some of the tools used in the CosmWasm ecosystem. Download and install Go 1.18.2 (as per requirements of Malaga-420) with the following commands:

wget https://dl.google.com/go/go1.18.2.linux-amd64.tar.gz
tar -xvf go1.18.2.linux-amd64.tar.gz
mv go /usr/local

Next, set the Go environment variables and update the PATH:

export GOROOT=/usr/local/go
export GOPATH=$HOME/go
export PATH=$GOPATH/bin:$GOROOT/bin:$PATH

Save these environment variables to your .bash_profile for future terminal sessions:

echo 'export GOROOT=/usr/local/go' >>~/.bash_profile
echo 'export GOPATH=$HOME/go' >>~/.bash_profile
echo 'export PATH=$GOPATH/bin:$GOROOT/bin:$PATH' >>~/.bash_profile
source ~/.bash_profile
echo 'source ~/.bash_profile' >> /etc/bash.bashrc

Clean up the Go tar.gz:

rm go1.18.2.linux-amd64.tar.gz

Step 4: Install Rust

Rust is the primary programming language for writing CosmWasm smart contracts. Install Rust with the following commands:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
echo "source $HOME/.cargo/env" >> ~/.bash_profile

Set the Rust default toolchain to stable and update it:

rustup default stable
rustup update stable

Add the wasm32-unknown-unknown target, which is required for compiling Rust code to WebAssembly:

rustup target list --installed
rustup target add wasm32-unknown-unknown

Step 5: Install wasmd

wasmd is a blockchain daemon built with CosmWasm support. Clone the wasmd repository and checkout to version 0.27.0 (as per requirements of Malaga-420):

git clone https://github.com/CosmWasm/wasmd.git
cd wasmd
git checkout v0.21.0

Build and install wasmd:

make install

Verify the installation by checking the version:

wasmd version

Step 6: Configure Testnet Environment

Source and save the environment variables for the CosmWasm testnet, malaga-420:

source <(curl -sSL https://raw.githubusercontent.com/CosmWasm/testnets/master/sandynet-1/defaults.env)
echo "source <(curl -sSL https://raw.githubusercontent.com/CosmWasm/testnets/master/sandynet-1/defaults.env)" >> ~/.bash_profile

Next, set the NODE environment variable with the Remote Procedure Call (RPC) endpoint and save it to .bash_profile:

echo 'export NODE="--node $RPC"'  >> ~/.bash_profile

Finally, set the TXFLAG environment variable with transaction-related flags (such as chain ID, gas prices, and gas adjustment) and save it to .bash_profile:

echo 'export TXFLAG="${NODE} --chain-id ${CHAIN_ID} --gas-prices 0.015umlg --gas auto --gas-adjustment 1.5"' >> ~/.bash_profile

The TXFLAG variable includes the following flags:

• ${NODE}: The RPC endpoint (previously set in the NODE variable).
• --chain-id ${CHAIN_ID}: The chain ID of the testnet.
• --gas-prices 0.015umlg: The gas prices for transactions (in this case, 0.015umlg).
• --gas auto: Automatically estimate the gas needed for a transaction.
• --gas-adjustment 1.5: Apply a 1.5x multiplier to the estimated gas for a transaction to account for variability.

Conclusions

In this article, we walked through the process of setting up CosmWasm development environment. With the tools and dependencies in place, we are now well-equipped to dive into the world of smart contracts and the Cosmos ecosystem. Happy coding!