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This article is about how to build linux and ubuntu ethernet private chain development environment, the editor thinks it is very practical, so I share it with you to learn. I hope you can get something after reading this article.

1. Pre-installation preparation 1.1 View the current CPU architecture

Execute the following command in the terminal to determine whether it is a 32-bit architecture or a 64-bit architecture:

~ $uname-px86_64

If you see the output x86x64, it's a 64-bit system, otherwise it's 32-bit.

1.2 download tools

Make sure you have installed the download tool wget:

~ $wget-VGNU Wget 1.17.1 built on linux-gnu

If wget is not already installed, use apt-get to install it

~ $sudo apt-get install wget

Second, install the DApp development environment

# # 2.1 install Node.js first download different precompiled versions depending on whether your ubuntu is 32-bit or 64-bit We use the official long-supported version of 8.10.0LTS: 64-bit: ~ $wget https://nodejs.org/dist/v8.10.0/node-v8.10.0-linux-x64.tar.gz 32-bit: ~ $wget https://nodejs.org/dist/v8.10.0/node-v8.10.0-linux-x86.tar.gz, and then extract it to the current directory, taking 64-bit as an example:

~ $tar zxvf node-v8.10.0-linux-x64.tar.gz

Then modify .bashrc to set the relevant environment variables:

~ $echo "export NODE_HOME=$HOME/node-v8.10.0-linux-x64" > > .bashrc ~ $echo "export NODE_PATH=$NODE_HOME/lib/node_modules" > > .bashrc ~ $echo "export PATH=$NODE_HOME/bin:$PATH" > > .bashrc

Finally, reload .bashrc (or log in again) to make node effective:

~ $source .bashrc

Now you can use node:

~ $node-vv8.10.0

# # 2.2 install Geth and execute the following command on the terminal:

~ $wget https://gethstore.blob.core.windows.net/builds/geth-linux-amd64-1.8.3-329ac18e.tar.gz~$ mv get-linux-amd64-1.8.3-329ac18e geth~$ echo export PATH=$HOME/geth:$PATH > > .bashrc ~ $soure .bashrc

After the installation is complete, execute the command to verify that the installation is successful:

~ $geth versionGethVersion: 1.8.3-stable2.3 installs solidity compiler ~ $npm install-g solc

After the installation is complete, execute the command to verify that the installation is successful

~ $solcjs-version0.40.2+commit.3155dd80.Emscripten.clang2.4 install web3~$ npm install-g web3@0.20.2

Installation verification:

~ $node-p 'require ("web3")' {[Function: Web3] providers: {… }} 2.5 install the truffle framework

Execute the following command to install the truffle development framework:

~ $npm install-g truffle

Verify the installation:

~ $truffle versionTruffle v4.1.3 (core 4.1.3) 2.6 install webpack

Execute the following command to install webpack:

~ $npm install-g webpack@3.11.0

Verify installation

~ $webpack-v3.11.0 III. Run Private chain Node 3.1 Genesis Block configuration

Create a node directory, node1, and create a private chained Genesis block profile in it:

~ $mkdir node1~$ cd node1~/node1 $touch private.json

Then edit the content as follows:

{"config": {"chainId": 7878, "homesteadBlock": 0, "eip155Block": 0, "eip158Block": 0}, "difficulty": "200"," gasLimit ":" 2100000 "," alloc ": {" 7df9a875a174b3bc565e6424a0050ebc1b2d1d82 ": {" balance ":" 300000 "}," f41c74c9ae680c1aa78f42e5647a62f353b7bdde ": {" balance ":" 400000 "}

Config.chainId: to declare the network number of Ethernet Square, select a number greater than 10.

Difficulty: used to declare the difficulty of mining, the smaller the value, the lower the difficulty, and the faster the block can be produced.

3.2 initialize private chain nodes

Execute the init command of geth to initialize the private chain node:

~ / node1 $geth-- datadir. / data init private.json

This creates a data directory under the current directory to store block data and account information:

~ / node1 $lsdata private.json

You can write the above command into a script init.sh to avoid typing so many things you can't remember each time:

~ / node1 $touch init.sh~node1 $chmod + x init.sh

The editing content is as follows:

#! / bin/bashgeth-- datadir. / data init private.json

When you deploy the next node, you can execute this script directly for initialization. For example, on another machine:

~ / node1 $. / init.sh3.3 starts the private chain node

Boot from the specified private chain data directory and set a different network number to start the node:

~ / node1 $geth-- rpc-- datadir. / data-- networkid 7878 console

Similarly, you can use a script console.sh to simplify the input when starting the node:

~ / node1 $touch console.sh~/node1 $chmod + x console.sh

The editing content is as follows:

#! / bin/bashgeth-- rpc\-- rpcaddr 0.0.0.0\-- rpccorsdomain "*"\-datadir. / data\-- networkid 7878\ console

Rpcaddr: used to declare the listening address of the node RPC API. If set to 0.0.0.0, the API can be accessed from other machines.

Rpccorsdomain: used to resolve security restrictions on cross-domain calls of web3 from browsers. To start the node later, just execute the script directly:

~ / node1 $. / console.sh3.4 account Management 3.4.1 View account list

In the geth console, use the accounts property of the eth object to view the current account list:

> eth.accounts []

Because we haven't created an account yet, the list is still empty.

3.4.2 create a new account

In the geth console, use the newAccount () method of the personal object to create a new account with a password of your choice:

> personal.newAccount ('7878787878') 0xd8bcf1324d566cbec5d3b67e6e14485b06a41d49

The output is the newly created account address (public key), and your output will not be the same as the example above. The geth is saved to the keystore file in the data directory. The password should be memorized by yourself and need to be used in the future.

3.4.3 query account balance

In the geth console, use the getBalance () method of the personal object to obtain the balance of the specified account. The parameter is the account address:

> eth.getBalance (eth.accounts [0]) 0

Or enter the account address directly:

> eth.getBalance ('0xd8bcf1324d566cbec5d3b67e6e14485b06a41d49') 0

Sure enough, the balance of the newly created account is 0.

3.4.4 Mining

Accounts without money can do nothing and need to dig mines to make some money. Execute the start () method of the miner object in the geth console to start mining:

> miner.start (1)

After a few minutes, check the account balance:

> eth.getBalance (eth.accounts [0]) 2.695e+21

There is a lot of money, 2695ETH. At present, the market capitalization is nearly 5 million RMB, ha. Execute the stop () method of the miner object to stop mining:

> miner.stop () 3.4.5 unlock the account

An unlocked account is required when deploying the contract. In the geth console, use the unlockAccount () method of the personal object to unlock the specified account, with the parameters of the account address and account password (the password specified when the account was created):

> eth.unlockAccount (eth.accounts [0], '78787878') true IV. Build sample project 4.1 New DApp project

Execute the following command to create a project directory and enter it:

~ $mkdir demo~$ cd demo

Then initialize the project skeleton structure with the webpack template:

~ / demo$ truffle unbox webpackDownloading... Unpacking... Setting up... Unbox successful. Sweet 4.2 install the NPM package on which the project depends

Execute the following command to install the nmp package:

~ / demo$ npm install4.3 modify truffle configuration

In truffle.js, modify port to 8545, because geth listens on port 8545 by default:

Module.exports = {networks: {development: {… Port: 8545... } 4.4 start the node

At the other terminal, execute the following command to start the node software to deploy the contract and execute the transaction:

~ $cd node1~/node1 $. / console.sh >

Note: in order to deploy the contract on the node, don't forget to unlock the account after starting geth:

> personal.unlockAcount (eth.accounts [0], '78787878') true4.5 compilation contract

Execute the following command to compile the project contract:

~ / demo$ truffle compile4.6 deployment contract

Execute the following command to deploy the contract:

~ / demo$ truffle migrate

If you forgot to unlock your account in the geth console, you will see the following error. You can unlock it by referring to the previous instructions:

Error: authentication needed: password or unlock

If you have unlocked the account correctly, you will see that the deployment process stops in the following state:

Replacing Migrations... 0x3088762a5bc9...

This is because truffle is waiting for the deployment deal to be submitted, but we haven't started mining in the private chain yet. Now switch back to the geth terminal window to view the status of the transaction pool:

> txpool.status {pending:1, queued:0}

Sure enough, there is a pending deal! Just start digging:

> miner.start (1)

Wait a moment, and then check the status of the trading pool:

> txpool.status {pending:0, queued:0}

The deal has been successfully submitted. We can stop digging because it takes up too much CPU:

> miner.stop ()

Now switch back to the truffle terminal, and the deployment process is completed correctly.

4.7 start DApp

Execute the following command to start DApp:

~ / demo$ npm run dev

Just visit http://localhost:8080 in your browser. If you want to be able to access your DApp application from another machine, modify package.json:

{scripts: {"dev": "webpack-dev-server-- host 0.0.0.0"}} above is how to build linux and ubuntu ethernet private chain development environment. The editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

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