[blockchain | Solana] Introduction to program development on Solana chain [source code]

In this tutorial , We will learn how to develop Solana Chain program , The content includes creating Solana account number 、 Get free... From the test chain SOL、 Compile, deploy and test process , And develop a simple Solana Chain program . At the end of the tutorial, you can download the complete source code .

Before delving into this tutorial , Please make sure that you have followed This tutorial The steps in set up the environment and install the tool kit . You can visit here to see Solana RPC API file .

1、 Connect to Solana Development Network

If you don't have your own node, don't worry ,Solana It provides the same configuration as the main network devnet. So here, let's start with API Endpoint Set as development chain - https://devnet.solana.com：

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[email protected]:~$ solana config set --url https://devnet.solana.com
Config File: /home/ubuntu/.config/solana/cli/config.yml
RPC URL: https://devnet.solana.com
WebSocket URL: wss://devnet.solana.com/ (computed)

2、 Get ready Solana account

Every program on the chain is actually a Account, But it is marked “Executable: true”, This means that it is an executable . To store this file , We need to create another one that can pay for Solana Account ：

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solana-keygen new

Enter the password and confirm , The new account is saved in  /home/ubuntu/.config/solana/id.json  in , As our default key . You can run the following command to check the public key ：

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[email protected]:~$ solana-keygen pubkey /home/ubuntu/.config/solana/id.json
7FqW6xXE4sMmZSeVxFsoTr83He4MhhePvA1vRAv9zgQf

stay Solana On the test chain , You can run the following commands for free SOL In order to perform subsequent operations ：

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[email protected]:~$ solana airdrop 10 7FqW6xXE4sMmZSeVxFsoTr83He4MhhePvA1vRAv9zgQf
Requesting airdrop of 10 SOL from 34.82.57.86:9900
10 SOL

Let's check our balance ：

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[email protected]:~$ solana balance 7FqW6xXE4sMmZSeVxFsoTr83He4MhhePvA1vRAv9zgQf
10 SOL

wow , rich .

Then we create another account , Used to store program files ：

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solana-keygen new -o solana_memo_program.json

ad locum , We use -o Option to output the new key pair to a new file solana_memo_program.json .

3、 compiler

from 1.4.x edition （2020-10-22 Release ） Start ,Solana Provides cargo-build-bpf and cargo-test-bpf Tools such as , Help us to cargo The project is compiled as BPF Format file .

have access to Solana The memo program provided by the official team to try this . First clone the warehouse ：

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git clone https://github.com/solana-labs/solana-program-library.git

Then jump to the folder solana-program-library/memo/program/ And run ：

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cargo build-bpf

This is the program we mentioned above cargo-build-bpf The wrapper . If you see the following error ：

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= note: /usr/bin/ld: cannot find Scrt1.o: No such file or directory
/usr/bin/ld: cannot find crti.o: No such file or directory
collect2: error: ld returned 1 exit status

That's because you lack some 32 Bit dependent package , Let's fix it by installing ：

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sudo apt install gcc-multilib

Then we compile again , obtain ：

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To deploy this program:
$ solana deploy /home/ubuntu/solana/solana-program-library/target/deploy/spl_memo.so

Okay , Ready to deploy , Here we deploy it to the account we created and export it to a file solana_memo_program.json, Let's get the key first ：

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solana-keygen pubkey ~/solana_memo_program.json
D8Cnv1UcThay2WijWP4SQ8G683UuVsKPaZEU7TNVKW1j

Then run the deployment ：

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solana deploy /home/ubuntu/solana/solana-program-library/target/deploy/spl_memo.so ~/solana_memo_program.json
{"programId":"D8Cnv1UcThay2WijWP4SQ8G683UuVsKPaZEU7TNVKW1j"}

Now we have successfully deployed a program to the test company , Program address ：D8Cnv1UcThay2WijWP4SQ8G683UuVsKPaZEU7TNVKW1j

To verify the results of the command line , Can be in Solana explorer Check our program on , go to https://explorer.solana.com/ And change the network to Devnet, Enter the program address , You might see ：

Yes , Our program is right there ！

4、 test Solana Program

In order to interact with our chain program , We need old friends here @solana/web3.js. Let's create a new js Project and add package @solana/web3.js：

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yarn init
yarn add @solana/web3.js

Then create a similar one in the root folder and test code index.js Entrance js file ：

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var solana_web3 = require('@solana/web3.js');
function testMemo(connection, account){
const instruction = new solana_web3.TransactionInstruction({
keys: [],
programId:new solana_web3.PublicKey('D8Cnv1UcThay2WijWP4SQ8G683UuVsKPaZEU7TNVKW1j'),
data: Buffer.from('cztest'),
});
console.log("account:", account.publicKey.toBase58())
solana_web3.sendAndConfirmTransaction(
connection,
new solana_web3.Transaction().add(instruction),
[account],
{
skipPreflight: true,
commitment: "singleGossip",
},
).then(()=>{console.log("done")}).catch((e)=>{console.log("error",e)});
}function main() {
connection = new solana_web3.Connection("https://devnet.solana.com", 'singleGossip');
const account = new solana_web3.Account()
const lamports = 10*1000000000
connection.requestAirdrop(account.publicKey, lamports).then(()=>{
console.log("airdrop done")
testMemo(connection, account)
});
}
main()

Let's see what happened here .

First connect to devnet Endpoint , And then we use solana_web3 Provided solana_web3.Account()  Function creation A new account , This account will be used to interact with our program later .

Then we go from devnet Get some free SOL , And then called this. testMemo function , This function sends a transaction to our program , Parameters are passed in as data streams （ Here we pass a string “ cztest ”）

Now? , Let's use Explorer again to check our Solana Program ：

The transaction shown above , We can see the data in hexadecimal format , have access to binascii Tools like to decode this data ：

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>>> import binascii
>>> binascii.a2b_hex('637a74657374')
b'cztest'

Here we can see that the result is the same as the string we sent to the program

5、 Write your own Solana Program

We just tried one from Solana official repo Program extracted from , So what should we do to write from scratch One Solana The program on the chain ？ As an ordinary Rust project ,Solana The program on the chain is also made by cargo Managed .

First , Let's use cargo To start our new project ：

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cargo new onchain_program

Then open it with your favorite editor onchain_program/Cargo.toml And add some basic information to the project ：

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[dependencies]
arrayref = "0.3.6"
num-derive = "0.3"
num-traits = "0.2"
num_enum = "0.5.1"
solana-program = "1.4.8"
thiserror = "1.0"[dev-dependencies]
solana-sdk = "1.4.8"[lib]
crate-type = ["cdylib", "lib"][package.metadata.docs.rs]
targets = ["x86_64-unknown-linux-gnu"]

We also added a Xargo.toml file , Used in compiling bpf Cross platform is supported when file . Then it's time to do it yourself , Let's write some Rust Code . First of all we have src/lib.rs Add an entry point to ：

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#![deny(missing_docs)]//! A simple program that return success.#[cfg(not(feature = "no-entrypoint"))]
mod entrypoint;// Export current sdk types for downstream users building with a different sdk version
pub use solana_program;

Then in the entry file entrypoint.rs Add some code to ：

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//! Program entrypointuse solana_program::{
account_info::AccountInfo, entrypoint, entrypoint::ProgramResult, program_error::ProgramError,
pubkey::Pubkey,
};
use std::str::from_utf8;entrypoint!(process_instruction);
fn process_instruction(
_program_id: &Pubkey,
_accounts: &[AccountInfo],
instruction_data: &[u8],
) -> ProgramResult {
Ok(())
}

This is a very simple program , We haven't done anything here , Just return success

function process_instruction Is the entire entry function we pass in the instruction structure . It contains all the information needed to execute the instruction ： _program_id Show program ,_accounts Indicates all accounts required in this instruction ,instruction_data It means that we use it to convey Serialized data stream of other parameters . When the program works well , We use Ok(()) Return to success , Or use Err(error) Return failed .

If you're ready , Next, you can deploy the program as you did before ：

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cargo build-bpf...To deploy this program:
$ solana deploy /home/ubuntu/solana/memo_test/onchain_program/target/deploy/onchain_program.so

6、 Conclusion

With the help of Solana All tools and SDK, We can use cargo Easy access to target files . Once you understand the whole process , You'll find it's just a Rust project , It USES rustrc Provided LLVM Translate it into BPF Format file , Then we deploy it on the chain . What I want to mention is , Developing Solana On chain program , Not all Rust Features can be used , Details can be stay here find . If you use 1.3.x Version of the tool suite , Then it needs to be xargo-build.sh.

The tutorial code can be downloaded from here ： example-helloworldhttps://github.com/solana-labs/example-helloworld#rust-limitations
solana-program-libraryhttps://github.com/solana-labs/solana-program-library cargo-build-bpfhttps://github.com/solana-labs/solana/tree/master/sdk/cargo-build-bpf