code: function(purpose) {
      const oThis = this;
  
      // Create empty ENV file
      fileManager.touch(setupConfig.env_vars_file, '#!/bin/sh');
      fileManager.append(setupConfig.env_vars_file, '#################');
      fileManager.append(setupConfig.env_vars_file, '# opentST Platform Environment file');
      fileManager.append(setupConfig.env_vars_file, '#################');
  
      logger.info('* writing env basic, geth, cache and addresses related env vars');
  
      // Create geth ENV variables
      oThis._gethVars(purpose);
  
      // Create cache ENV variables
      oThis._cacheVars();
  
      // Create notification ENV variables
      oThis._notificationVars();
  
      // Create miscellaneous ENV variables
      oThis._miscellaneousVars();
  
      // Create dynamodb ENV variables
      oThis._dynamodbVars();
  
      // Create dynamodb auto scaling ENV variables
      oThis._dynamodbAutoScalingVars();
  
      // Create contract address ENV variables
      oThis._contractAddressVars();
  
      // Create address ENV variables
      oThis._addressVars();
    }
docs: Generate ENV file from config.js