Ethereum in Practice

This chapter introduces the Ethereum development environment. Several examples will be presented in this chapter to complement the theoretical concepts provided in the previous chapter.

We will begin by considering the practical payment process in Ethereum, and some recent and upcoming innovations to the blockchain. We will then look at test nets, which can play a vital role in testing the smart contracts before deploying on the main net. Then, we will look at the private net option in Ethereum, which allows the creation of an independent private network. This private network can be used as a shared distributed ledger between participating entities and for the development and testing of smart contracts.

While there are other clients available for Ethereum, Geth is the leading client for Ethereum and the standard tool of choice, and as such, this chapter uses Geth for the examples. We will also use Remix IDE to write smart contracts and MetaMask to deploy...

Ethereum payments

In this section, we will see how Ethereum works from a user’s point of view. For this purpose, we will present the most common use case of transferring funds—in our use case, from one user (Bashir) to another (Irshad). We will use two Ethereum clients, one for sending funds and the other for receiving. There are several steps involved in this process, as follows:

1. First, either a user requests money by sending the request to the sender, or the sender decides to send money to the receiver. We can use any Ethereum wallet software. The request can be sent by sending the receiver’s Ethereum address to the sender.

   For example, there are two users, Bashir and Irshad. If Irshad requests money from Bashir, then she can send a request to Bashir by using a QR code. Once Bashir receives this request, he will either scan the QR code or manually type in Irshad’s Ethereum address and send the Ether to Irshad’s address. This request...

Innovations in Ethereum

In this section we will cover some of the innovations in Ethereum. Ethereum is under constant development. Just like BIPs, we have Ethereum improvement proposals (EIPS) in Ethereum to suggest and implement improvements in Ethereum. You can track EIPs here: https://eips.ethereum.org. Now we will cover some important improvements.

Difficulty time bomb

In addition to timestamp difference-based difficulty adjustment, there is also another element that increases mining difficulty exponentially after every 100,000 blocks. This is the so-called difficulty time bomb, or ice age, introduced in the Ethereum network, which will make it very hard to mine on the Ethereum blockchain at some point in the future.

Once activated, over time, the difficulty bomb makes mining on Ethereum 1.x so prohibitively slow that it becomes infeasible, resulting in a so-called “ice age.” In other words, this mechanism exponentially increases the PoW mining difficulty...

Programming with Geth

First, we describe Geth and explore various operations that can be performed using this client.

Installing and configuring the Geth client

The installation procedure detailed at https://geth.ethereum.org/docs/getting-started/installing-geth describes the installation of Ethereum clients on macOS and Linux. Instructions for other operating systems are also available.

Once installation is complete, Geth can be launched simply by issuing the geth command at the terminal. It comes preconfigured with all the required parameters to connect to the live Ethereum network (main net):

$ geth

When the Ethereum client starts up, it starts to synchronize with the rest of the network. There are three types of synchronization mechanisms available, namely, snap, full, and light:

• Snap: This is the default mode that keeps the most recent 128 blocks’ states in memory, enabling immediate access to transactions in this range. The node in this...

Setting up a development environment

A usual and sensible approach to develop and test Ethereum smart contracts is within a local private net or a simulated environment like Ganache. After all the relevant tests are successful on a public test net, the contracts can then be deployed to the public main net. There are, however, variations in this process.

Many developers opt to only develop and test contracts on a local simulated environment and then deploy them onto the public main net or their private/enterprise production blockchain networks. Developing first on a simulated environment and then deploying directly to a public network can lead to faster time to production, as setting up private networks may take longer compared to setting up a local development environment with a blockchain simulator.

There are new tools and frameworks available, like Truffle and Ganache, which make development and testing for Ethereum easier. We will look into these tools in more depth in...

Introducing Remix IDE

There are various Integrated Development Environments (IDEs) available for Solidity development. Most of the IDEs are available online and are presented via web interfaces. Remix (formerly Browser-Solidity) is the most commonly used IDE for building and debugging smart contracts. It is discussed here.

Remix is a web-based environment for the development and testing of contracts using Solidity. It is a feature-rich IDE that does not run on a live blockchain; in fact, it is a simulated environment in which contracts can be deployed, tested, and debugged. It is available at https://remix.ethereum.org.

An example interface is shown as follows:

Figure 10.3: Remix IDE

On the left-hand side, there is a column with different icons. These icons represent various plugins of the Remix IDE. When you run Remix for the first time, it won’t show any of the plugins. In order to add plugins to Remix IDE, you need to access the plugin manager to activate...

Interacting with the Ethereum Blockchain with MetaMask

MetaMask allows interaction with the Ethereum blockchain via the Firefox and Chrome browsers. It injects a web3 object within the running website’s JavaScript context, which allows immediate interface capability for dApps. This injection allows dApps to interact directly with the blockchain.

Further information is available at https://github.com/MetaMask/metamask-plugin.

MetaMask also allows account management and records all transactions for these accounts. This acts as a verification method before any transaction is executed on the blockchain. The user is shown a secure interface to review the transaction for approval or rejection before it can reach the target blockchain.

It allows connectivity with various Ethereum networks. An interesting feature to note is that MetaMask can connect to any Ethereum blockchain via the custom RPC connection. It can connect to not only remote blockchains but also...

Summary

In this chapter, we have explored Ethereum test networks and how to set up private Ethereum networks. After the initial introduction to private network setup, we also saw how the Geth command-line tool can be used to perform various functions and how we can interact with the Ethereum blockchain. We also saw how MetaMask and Remix can be used to deploy smart contracts.

In the next chapter, we will see in greater detail what tools, programming languages, and frameworks are available for the development of smart contracts on Ethereum.

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