Magento – Install magento via Puppet or Composer

• Install module via composer is the best way to Magento 2. Becuase there are many advantages if we install module via composer.

• If you want to upgrade module you just need to change the version in composer.json file and run composer update command at the rootMagentoento.

• While in manual installation you need to first download module and replace old files and run setup:upgrade command to upgrade module.

• All modules which are installed via composer are downloaded in vendor folder.

• Magento uses default https://repo.magento.com/ URL to download module If you purchase module from Magento Marketplace.

• If you purchase module from third-party website. You need to add a repository in composer.json to download and install a module.

For Example

"repositories": {
    "0": {
        "type": "composer",
        "url": "https://repo.magento.com/" //Default Magento Repositry
    },
    "thirdparty-module": {
        "type": "composer",
        "url": "https://mymodule.thirdparty.com/" //Third Party Repositary
    }
},

In my opinion composer is the best and proper way to install module in Magento 2.

Install Third Party Module Via composer:

1. Run this command to add new repository in conposer.json

composer config repositories.thirdparty-module git https://thirdparty-composer-url.com

2. Now run this command to add component and version of module in composer.json

composer require [component-name]:[version]

Forex.  composer require prince/helloword:1.0.0

3. Now run composer update to download module from repository.

composer update

4. Now run setup:upgrade to install and register module in config.php

php bin/magento setup:upgrade

If not, is the best approach here to simply copy & paste any dependencies into the main project composer.json? That's pretty inelegant.

Yes, given that the extension is manually copied to app/code, this is the best approach, and yes, this is pretty inelegant.

The real best solution is to not copy the extension manually. It already has a composer.json file, so you can install it with composer. Set up a private repository (for example at Bitbucket or on the local filesystem outside of the Magento root), specify it in repositories of your composer.json and then require the module as any other composer module.