Differences in the v7 stack from our stack older versions

What stays the same with the v7 Stack

• Engine Yard's Stack v7 continues on the path set by v6 and is based on the Ubuntu LTS distribution. 
• Chef runs in the same way that on v6, meaning custom cookbooks are executed after main recipes, and main recipes' behavior can be modified through the know overlay method.
• Services can continue to be enabled through environment variables like 'EY_REDIS_ENABLED=true' and 'EY_SIDEKIQ_ENABLED=true'.

What changes with the v7 Stack

• All core chef recipes have been renamed to include the 'ey-' prefix.  Meaning what used to be 'redis' now is named 'ey-redis'.  This impacts custom recipes that overlay core ones, although a simple change on name & paths should be enough.
• As part of every release, all core Chef recipes now are going through a linter.  Hopefully the code is easier to read now.
• Graviton-based instances are available, and can be added to an environment alongside x86 ones.  This means the same set of Chef recipes run on both.
• To deploy applications on v7, version 3.0.4 of Serverside (the EYC deployment process) has to be used.

A comparison of features across all EYC Stack's can be found here.