Download Debian Package and all dependencies (node)

downloader

// remote
const axios = require( "axios" );
const cheerio = require( "cheerio" );
const path = require( "path" );
const fs = require( "fs" );
const { exec } = require( "child_process" );
const crypto = require( "crypto" );


// vars
const downloaded_packages = new Set();


// config
const package_name = "wpasupplicant";
const repo_name = "bookworm";
const arch = "amd64";
const mirror = "ftp.us.debian.org/debian";
const download_dir = path.resolve( "..", "packages" );


// run
run( package_name );


// code

function run(
	package_name
) {

	console.log( `run [${ package_name }]` );

	if ( ! fs.existsSync( download_dir ) ) {

		console.log( `download_dir does not exist, creating [${ download_dir }]` )
		fs.mkdirSync( download_dir );

	}

	process.chdir( download_dir );

	downloadPackage( package_name );

}

async function downloadPackage(
	package_name
) {

	console.log( `downloadPackage [${ package_name }]` );

	// If the package has already been downloaded, return
	if ( downloaded_packages.has( package_name ) ) {
		console.log( `Already downloaded` );
		return;
	}

	const url = `https://packages.debian.org/${ repo_name }/${ package_name }`;
	const response = await axios.get( url );
	const $ = cheerio.load( response.data );

	const package_el = $( "#pdownload a" ).filter( ( i, el ) => $( el ).text() === arch )[0];
	if ( package_el ) {

		console.log( `has package_el` );

		const download_page_url = $( package_el ).attr( "href" );
		console.log( `download_page_url [${ download_page_url }]` );

		const result = await parseDownloadPage( `https://packages.debian.org${ download_page_url }` );
		const file_name = path.resolve( ".", result.download_url.split( "/" ).pop() );

		let did_download = false;
		if ( checkFileExists( file_name ) ) {
			console.log( "File already exists" );

			const local_sha_256 = getFileSHA256( file_name );
			console.log( `local_sha_256 [${ local_sha_256 }]` );
			if ( local_sha_256 !== result.sha_256 ) {
				console.warn( "File is damaged, deleting" );
				fs.rmSync( file_name );
				did_download = true;
				await execPromise( `wget ${ result.download_url }` );
			}

		}
		else {
			did_download = true;
			await execPromise( `wget ${ result.download_url }` );
		}

		if ( did_download ) {

			const local_sha_256 = getFileSHA256( file_name );
			console.log( `local_sha_256 [${ local_sha_256 }]` );
			if ( local_sha_256 !== result.sha_256 ) {
				console.error( `File is damaged [${ file_name }]` );
			}

		}

		downloaded_packages.add( package_name );

	}
	else {
		console.log( `missing package_el` );
	}

	const dependencies = $( ".uldep a" );

	// Download each dependency using wget
	for ( let i = 0; i < dependencies.length; i++ ) {

		const dependency_name = $( dependencies[ i ] ).text().trim();
		console.log( `dependency_name [${ dependency_name }]` );

		await downloadPackage( dependency_name );

	}

}

async function parseDownloadPage(
	url
) {

	console.log( `parseDownloadPage [${ url }]` );

	const response = await axios.get( url );
	const $ = cheerio.load( response.data );

	const download_url = $( $( "#content a" ).filter( ( i, el ) => $( el ).text() === mirror )[0] ).attr( "href" );

	console.log( `download_url [${ download_url }]` );

	const sha_256 = $( $( "#pdownloadmeta tr" ).filter( ( i, el ) => {
		return ( $( el ).find( "th" ).text() === "SHA256 checksum" );
	})[0] ).find( "tt" ).text().trim();

	console.log( `sha_256 [${ sha_256 }]` );

	return {
		download_url: download_url,
		sha_256: sha_256
	};

}

function checkFileExists(
	file_name
) {

	return fs.existsSync( file_name );

}

function getFileSHA256(
	file_path
) {

	const content = fs.readFileSync( file_path );
	const hashSum = crypto.createHash( "sha256" );
	hashSum.update( content );

	return hashSum.digest( "hex" );

}

function execPromise(
	command
) {

	return new Promise( ( resolve, reject ) => {

		exec(
			command,
			( error, stdout, stderr ) => {

				if ( error ) {
					console.error( `exec error: ${ error }` );
					return reject( error );
				}

				return resolve( stdout );

			}
		);

	});

}

TODO: add in hash verification

Updated to check against sha256 and re-download if mismatched

Especially useful if you are setting up a machine that needs a package installed to get on the network