Importing Drupal 8 config programmatically

import.php

<?php

// Import arbitrary config from a variable.
// Assumes $data has the data you want to import for this config.
$config = \Drupal::service('config.factory')->getEditable('filter.format.basic_html');
$config->setData($data)->save();

// Or, re-import the default config for a module or profile, etc.
\Drupal::service('config.installer')->installDefaultConfig('module', 'my_custom_module');

// Or, import YAML config from an arbitrary file.
$config_path = drupal_get_path('module', 'my_custom_module') . '/config/install';
$source = new FileStorage($config_path);
$config_storage = \Drupal::service('config.storage');
$config_storage->write('filter.format.basic_html', $source->read('filter.format.basic_html'));


// Create a fieds from config. 
use Drupal\taxonomy\Entity\Term;
use Drupal\Core\Config\FileStorage;
 
/**
 * Implement hook_install().
 */
function client_business_logic_install() {
  // Obtain configuration from yaml files
  $config_path = 'path/to/config';
  $source      = new FileStorage($config_path);
 
  // Obtain the storage manager for vocabularies
  // Create a new vocabulary from the yaml configuration and save
  \Drupal::entityManager()->getStorage('taxonomy_vocabulary')
    ->create($source->read('taxonomy.vocabulary.business_logic_vocab'))
    ->save();
 
  // Obtain the storage manager for field storage bases
  // Create a new field from the yaml configuration and save
  \Drupal::entityManager()->getStorage('field_storage_config')
    ->create($source->read('field.storage.taxonomy_term.field_machine_name'))
    ->save();
 
  // Obtain the storage manager for field instances
  // Create a new field instance from the yaml configuration and save
  \Drupal::entityManager()->getStorage('field_config')
    ->create($source->read('field.field.taxonomy_term.business_logic_vocab.field_machine_name'))
    ->save();