After following the instructions on how to add a Youtube plugin in CKEditor and adding the code to config.js, I was disappointed to find that the youtube insert button did not show up on the toolbar.
My next step was downloading and extracting the Youtube plugin to a folder, and then adding the following code to config.js:
config.extraPlugins = "plugin1,plugin2,youtube";
Even after this adjustment, the insert button still did not appear in the toolbar. I tried adding it to the items in toolbar like this:
{ name: 'styles', items: [ 'Styles', 'Format','youtube' ] }
Unfortunately, the insert button remained elusive on the toolbar.