Using ipfs with etheruem

December 23, 2019

Using ipfs with etheruem

Ipfs is a decentralized tool , it’s very suitable for ethereum.

We also use Smart Contract to store “data” in the etheruem blockchain.

Today , We use Smart Contract to store “data（ipfs hash）” , for the purpose of immutability .

IPFS

What’s IPFS ?

ipfs> IPFS introduction from wiki

The InterPlanetary File System (IPFS) is a protocol and peer-to-peer network for storing and sharing data in a distributed file system. IPFS uses content-addressing to uniquely identify each file in a global namespace connecting all computing devices.

IPFS allows users to not only receive but host content, in a similar manner to BitTorrent. As opposed to a centrally located server, IPFS is built around a decentralized system of user-operators who hold a portion of the overall data, creating a resilient system of file storage and sharing. Any user in the network can serve a file by its content address, and other peers in the network can find and request that content from any node who has it using a distributed hash table (DHT).

Why we use ipfs ?

We know we can’t upload pictures on Ethereum, because uploading pictures on Ethereum has to pay a high gas fees.

gas feesWe can upload the ipfs hash to Ethereum Blockchain .

How do we do ? Let’s go with our tutorial .

Tutorial

We will use Ipfs to upload the file and deploy the **Hash (Ipfs generate) **on the Ethereum blockchain .

First : Prepare List

Chrome
Metamask
Remix
IPFS Desktop / Extension- Chrome

Google Chrome is a good browser can use many extensions on it .

Google Chrome 網路瀏覽器 *Google 內建的智慧功能可為你提供無比簡易、安全又快速的使用體驗。*www.google.com 2. Metamask

Metamask is not only a ethereum wallet but a chrome extension .

MetaMask *Get Chrome Extension Chrome Firefox Opera Brave iOS (beta) Android (beta) MetaMask is a bridge that allows you to visit…*metamask.io o 3. Remix

Remix is a smart contract complier and we also use it to test our smart contract .

Remix - Ethereum IDE Edit descriptionremix.ethereum.org 4. IPFS Desktop /Extension

mac : https://github.com/ipfs-shipyard/ipfs-desktop/releases/download/v0.10.2/ipfs-desktop-0.10.2.dmgwindows : https://github.com/ipfs-shipyard/ipfs-desktop/releases/download/v0.10.2/ipfs-desktop-setup-0.10.2.exe ipfs-shipyard/ipfs-desktop *A desktop client for IPFS. You don’t need the command line to run an IPFS node. Just install IPFS Desktop and have all…*github.com #### Second : Write smart contract on Remix

if we install metamask on browser , and we change the network to Ropsten Testnet , and get the ether from faucet .

Faucet

You can get the ether from faucet.

Test Ether Faucet Edit descriptionfaucet.metamask.io > Remix

If you first use Remix , please click the **solidity button **in Eviroments.

2. Create a new file on FILE EXPLORERS and we named it “ipfs_inbox.sol” .

> Code on it .

pragma solidity ^0.4.23; contract ipfs_store { string ipfsHash;

function sendHash(string x) public { ipfsHash = x; }function getHash() public view returns (string x) { return ipfsHash; } }3. Click the icon “SOLIDITY COMPILER” , and click compile ipfs_inbox.sol .

And you can see your contract ABI and Bytecode on it .

4. Change to DEPLOY & RUN TRANSACTIONS