Setting up a locally hosted blockchain

Overview

One of the ways we will be testing the write operations of our dashboard is by setting up a locally-hosted blockchain. We accomplish this with Truffle and Ganache, using the tokens in centre-tokens. Although truffle/ganache are both documented thoroughly, this article serves as a quick reference to setting it up for the specific needs of our project.

Installation

These are the minimum prerequisites that must be completed before setting up the local blockchain:

1. Install ganache-cli, our test RPC client.

   $ npm i -g ganache-cli
   

2. Install truffle, our development environment for creating our blockchain.

   $ npm i -g truffle
   

3. Clone the centre-tokens repository to any location on your machine. This is where the truffle config is defined.

   $ git clone https://github.com/centrehq/centre-tokens.git
   

4. Install dependencies in the centre-tokens directory.

   centre-tokens$ npm install
   

Launching Local Blockchain

1. Compile the defined truffle configurations.

   centre-tokens$ truffle compile
   

   For context, this compiles truffle-config.js, contracts/**, and migrations/**.

2. Start the block-chain locally.

   centre-tokens$ npm run ganache -- -p 8545 -h localhost
   

   The output should look EXACTLY the same as

   Available Accounts
   ==================
   (0) 0x90F8bf6A479f320ead074411a4B0e7944Ea8c9C1 (1000000 ETH)
   (1) 0xFFcf8FDEE72ac11b5c542428B35EEF5769C409f0 (1000000 ETH)
   (2) 0x22d491Bde2303f2f43325b2108D26f1eAbA1e32b (1000000 ETH)
   (3) 0xE11BA2b4D45Eaed5996Cd0823791E0C93114882d (1000000 ETH)
   (4) 0xd03ea8624C8C5987235048901fB614fDcA89b117 (1000000 ETH)
   (5) 0x95cED938F7991cd0dFcb48F0a06a40FA1aF46EBC (1000000 ETH)
   (6) 0x3E5e9111Ae8eB78Fe1CC3bb8915d5D461F3Ef9A9 (1000000 ETH)
   (7) 0x28a8746e75304c0780E011BEd21C72cD78cd535E (1000000 ETH)
   (8) 0xACa94ef8bD5ffEE41947b4585a84BdA5a3d3DA6E (1000000 ETH)
   (9) 0x1dF62f291b2E969fB0849d99D9Ce41e2F137006e (1000000 ETH)
   (10) 0x610Bb1573d1046FCb8A70Bbbd395754cD57C2b60 (1000000 ETH)
   (11) 0x855FA758c77D68a04990E992aA4dcdeF899F654A (1000000 ETH)
   (12) 0xfA2435Eacf10Ca62ae6787ba2fB044f8733Ee843 (1000000 ETH)
   (13) 0x64E078A8Aa15A41B85890265648e965De686bAE6 (1000000 ETH)
   (14) 0x2F560290FEF1B3Ada194b6aA9c40aa71f8e95598 (1000000 ETH)
   
   Private Keys
   ==================
   (0) 0x4f3edf983ac636a65a842ce7c78d9aa706d3b113bce9c46f30d7d21715b23b1d
   (1) 0x6cbed15c793ce57650b9877cf6fa156fbef513c4e6134f022a85b1ffdd59b2a1
   (2) 0x6370fd033278c143179d81c5526140625662b8daa446c22ee2d73db3707e620c
   (3) 0x646f1ce2fdad0e6deeeb5c7e8e5543bdde65e86029e2fd9fc169899c440a7913
   (4) 0xadd53f9a7e588d003326d1cbf9e4a43c061aadd9bc938c843a79e7b4fd2ad743
   (5) 0x395df67f0c2d2d9fe1ad08d1bc8b6627011959b79c53d7dd6a3536a33ab8a4fd
   (6) 0xe485d098507f54e7733a205420dfddbe58db035fa577fc294ebd14db90767a52
   (7) 0xa453611d9419d0e56f499079478fd72c37b251a94bfde4d19872c44cf65386e3
   (8) 0x829e924fdf021ba3dbbc4225edfece9aca04b929d6e75613329ca6f1d31c0bb4
   (9) 0xb0057716d5917badaf911b193b12b910811c1497b5bada8d7711f758981c3773
   (10) 0x77c5495fbb039eed474fc940f29955ed0531693cc9212911efd35dff0373153f
   (11) 0xd99b5b29e6da2528bf458b26237a6cf8655a3e3276c1cdc0de1f98cefee81c01
   (12) 0x9b9c613a36396172eab2d34d72331c8ca83a358781883a535d2941f66db07b24
   (13) 0x0874049f95d55fb76916262dc70571701b5c4cc5900c0691af75f1a8a52c8268
   (14) 0x21d7212f3b4e5332fd465877b64926e3532653e2798a11255a46f533852dfe46
   
   HD Wallet
   ==================
   Mnemonic:      myth like bonus scare over problem client lizard pioneer submit female collect
   Base HD Path:  m/44'/60'/0'/0/{account_index}
   
   Gas Price
   ==================
   20000000000
   
   Gas Limit
   ==================
   6721975
   
   Call Gas Limit
   ==================
   9007199254740991
   
   Listening on localhost:8545
   

   Tip: save the 15 account addresses and private keys to somewhere else since the ganache server produces a lot of output and you might lose the addresses when testing locally.

3. Deploy contracts to the block-chain.

   IMPORTANT: now open a new terminal tab to keep your block-chain server running!

   centre-tokens$ npm run migrate
   

   The output should look something like

   Compiling your contracts...
   ===========================
   > Everything is up to date, there is nothing to compile.
   
   Starting migrations...
   ======================
   > Network name:    'development'
   > Network id:      1605989681002
   > Block gas limit: 6721975 (0x6691b7)
   
   1_initial_migration.js
   ======================
   
      Deploying 'Migrations'
      ----------------------
      ...
   
   2_deploy_v1.js
   ==============
   Proxy Admin:   0x2F560290FEF1B3Ada194b6aA9c40aa71f8e95598
   Owner:         0xE11BA2b4D45Eaed5996Cd0823791E0C93114882d
   Master Minter: 0x3E5e9111Ae8eB78Fe1CC3bb8915d5D461F3Ef9A9
   Pauser:        0xACa94ef8bD5ffEE41947b4585a84BdA5a3d3DA6E
   Blacklister:   0xd03ea8624C8C5987235048901fB614fDcA89b117
   Deploying implementation contract...
   
      Deploying 'FiatTokenV1'
      -----------------------
      ...
   
      Deploying 'FiatTokenProxy'
      --------------------------
      > transaction hash:    0xfa9ad043a309b6047000c8d2a3b57435115b3c608b7eef2818c1d38ee861bda2
      > Blocks: 0            Seconds: 0
      > contract address:    0xC89Ce4735882C9F0f0FE26686c53074E09B0D550
      > block number:        5
      > block timestamp:     1605989824
      > account:             0x90F8bf6A479f320ead074411a4B0e7944Ea8c9C1
      > balance:             999999.92802742
      > gas used:            486261 (0x76b75)
      > gas price:           20 gwei
      > value sent:          0 ETH
      > total cost:          0.00972522 ETH
      ...
   
   3_deploy_v2.js
   ==============
   FiatTokenProxy:  0xC89Ce4735882C9F0f0FE26686c53074E09B0D550
   Deploying FiatTokenV2 implementation contract...
   
      Deploying 'FiatTokenV2'
      -----------------------
      ...
   
   4_deploy_v2_upgrader.js
   =======================
      ...
   
   
   Summary
   =======
   ...
   

   The account roles that it produces should exactly match:

   Owner:         0xE11BA2b4D45Eaed5996Cd0823791E0C93114882d
   Master Minter: 0x3E5e9111Ae8eB78Fe1CC3bb8915d5D461F3Ef9A9
   Pauser:        0xACa94ef8bD5ffEE41947b4585a84BdA5a3d3DA6E
   Blacklister:   0xd03ea8624C8C5987235048901fB614fDcA89b117
   

   The private keys for these accounts should have been provided for you in the step above.

   However, the FiatTokenProxy address should be different every time you run this. For now, copy this proxy address (FiatTokenProxy contract address) into your clipboard.

4. Go to metamask in your browser and switch your Network to Localhost 8545

   

5. Set up the contract address on the app locally.

   Copy and paste the FiatTokenProxy contract address from step 3 into your .env file:

   USDC_CONTRACT_ADDRESS = '{{PASTE_FIAT_TOKEN_PROXY_CONTRACT_ADDRESS}}'

   NOTE: this address is different every time you run your blockchain server.

6. Open up localhost:3000 and run the app. You might notice that there are no transactions displayed. This is because there is no transaction history on your new blockchain. To create transactions, you can either:

   1. Import accounts into metamask and create transactions. You get your account's private keys from the terminal from step 2. You can check if the transaction went through with the /transactions page.

   2. Use the /transfers page.