docs: truffle guide (#394)

* add truffle guide, update broken links

* cleanup

* update guide

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>
Co-authored-by: Federico Kunze <federico.kunze94@gmail.com>

docs/DOCS_README.md

@@ -11,7 +11,7 @@ If you want to open a PR on the Cosmos SDK to update the documentation, please f
 
 ## Docs Build Workflow
 
-The documentation for Ethermint is hosted at https://ethermint.cosmos.network/
+The documentation for Ethermint is hosted at https://docs.ethermint.zone/
 
 built from the files in this (`/docs`) directory for
 [master](https://github.com/cosmos/ethermint/tree/master/docs).

docs/README.md

@@ -57,5 +57,4 @@ aside: false
 
 ## Contribute
 
-See [this file](https://github.com/cosmos/ethermint/blob/master/docs/DOCS_README.md) for details of the build process and
-considerations when making changes.
+See [this file](https://github.com/ChainSafe/ethermint/blob/development/docs/DOCS_README.md) for details of the build process and considerations when making changes.

docs/core/encoding.md

@@ -70,4 +70,4 @@ will call this method for each necessary module.
 
 ## Next {hide}
 
-Learn how to connect Ethermint to [Metamask](./../guides/metamask.md) {hide}
+Learn how to deploy a Solidity smart contract on Ethermint using [Truffle](./../guides/truffle.md) {hide}

docs/guides/README.md

@@ -8,4 +8,5 @@ parent:
 
 This section contains different guides to use polular Ethereum tools with Ethermint.
 
-1. [Metamask](./metamask.md)
+1. [Truffle](./truffle.md)
+2. [Metamask](./metamask.md)

docs/guides/metamask.md

@@ -1,5 +1,5 @@
 <!--
-order: 1
+order: 2
 -->
 
 # Metamask

docs/guides/truffle.md

@@ -0,0 +1,167 @@
+<!--
+order: 1
+-->
+
+# Truffle
+
+Set up a Truffle Ethermint local development environment. {synopsis}
+
+## Pre-requisite Readings
+
+- [Installation](./../quickstart/installation.md) {prereq}
+- [Run a node](./../quickstart/run_node.md) {prereq}
+
+[Truffle](https://www.trufflesuite.com/truffle) is a development framework for deploying and managing [Solidity](https://github.com/ethereum/solidity) smart contracts. In this guide, we will learn how to deploy a contract to a running Ethermint network.
+
+## Install dependencies
+
+First, install the latest Truffle version on your machine globally.
+
+```bash
+npm install truffle -g
+```
+
+You will also need to install Ethermint. Check this [document](./../quickstart/installation.md) for the full instructions.
+
+## Create Truffle Project
+
+In this step we will create a simple counter contract. Feel free to skip this step if you already have your own compiled contract.
+
+Create a new directory to host the contracts and initialize it
+
+```bash
+mkdir ethermint-truffle
+cd ethermint-truffle
+```
+
+Initialize the Truffle suite with:
+
+```bash
+truffle init
+```
+
+Create `contracts/Counter.sol` containing the following contract:
+
+```javascript
+pragma solidity ^0.5.11;
+
+contract Counter {
+  uint256 counter = 0;
+
+  function add() public {
+    counter++;
+  }
+
+  function subtract() public {
+    counter--;
+  }
+
+  function getCounter() public view returns (uint256) {
+    return counter;
+  }
+}
+```
+
+Compile the contract using the `compile` command:
+
+```bash
+truffle compile
+```
+
+Create `test/counter_test.js` containing the following tests in Javascript using [Mocha](https://mochajs.org/):
+
+```javascript
+const Counter = artifacts.require("Counter")
+
+contract('Counter', accounts => {
+  const from = accounts[0]
+  let counter
+
+  before(async() => {
+    counter = await Counter.new()
+  })
+
+  it('should add', async() => {
+    await counter.add()
+    let count = await counter.getCounter()
+    assert(count == 1, `count was ${count}`)
+  })
+})
+```
+
+## Truffle configuration
+
+Open `truffle-config.js` and uncomment the `development` section in `networks`:
+
+```javascript
+    development: {
+     host: "127.0.0.1",     // Localhost (default: none)
+     port: 8545,            // Standard Ethereum port (default: none)
+     network_id: "*",       // Any network (default: none)
+    },
+```
+
+This will allow your contract to connect to your Ethermint local node.
+
+## Start Node and REST server
+
+Start your local node using the following command on the Terminal
+
+```bash
+# on the ~/ethermint/ directory
+init.sh
+```
+
+::: tip
+For further information on how to run a node, please refer to [this](./../quickstart/run_node.md) quickstart document.
+:::
+
+In another Terminal wintdow/tab, start the [REST and JSON-RPC server](./../quickstart/clients.md#rest-and-tendermint-rpc.md):
+
+```bash
+emintcli rest-server --laddr "tcp://localhost:8545" --unlock-key mykey--chain-id 8 --trace
+```
+
+## Deploy contract
+
+Back in the Truffle terminal, migrate the contract using
+
+```bash
+truffle migrate --network development
+```
+
+You should see incoming deployment logs in the Ethermint daemon Terminal tab for each transaction (one to deploy `Migrations.sol` and the oether to deploy `Counter.sol`).
+
+```bash
+I[2020-07-15|17:35:59.934] Added good transaction                       module=mempool tx=22245B935689918D332F58E82690F02073F0453D54D5944B6D64AAF1F21974E2 res="&{CheckTx:log:\"[]\" gas_wanted:6721975 }" height=3 total=1
+I[2020-07-15|17:36:02.065] Executed block                               module=state height=4 validTxs=1 invalidTxs=0
+I[2020-07-15|17:36:02.068] Committed state                              module=state height=4 txs=1 appHash=76BA85365F10A59FE24ADCA87544191C2D72B9FB5630466C5B71E878F9C0A111
+I[2020-07-15|17:36:02.981] Added good transaction                       module=mempool tx=84516B4588CBB21E6D562A6A295F1F8876076A0CFF2EF1B0EC670AD8D8BB5425 res="&{CheckTx:log:\"[]\" gas_wanted:6721975 }" height=4 total=1
+```
+
+## Run Truffle tests
+
+Now, you can run the Truffle tests using the Ethermint node using the `test` command:
+
+```bash
+truffle test --network development
+
+Using network 'development'.
+
+
+Compiling your contracts...
+===========================
+> Everything is up to date, there is nothing to compile.
+
+
+
+  Contract: Counter
+    ✓ should add (5036ms)
+
+
+  1 passing (10s)
+```
+
+## Next {hide}
+
+Learn how to connect Ethermint to [Metamask](./../guides/metamask.md) {hide}