Allow images in ckeditor in Drupal to be styled

By default CKEditor applies dimension styling directly to the image element. This makes it difficult to allow your images to be responsive.

To fix this, install the CKEditor Image module.

cd sites/all/modules

drush dl ckeditor_image

sudo chgrp -R www-data .

In CKEditor settings, under the profile’s Editior appearance, check CKEditor Image and uncheck Enhanced Image Plugin.

Then, when you right-click an image in the CKEditor and select Image properties, you will see this:

This dialog will allow you to assign a class to the image to make it responsive.