Breaking changes and incompatibilities

Every Engine release strives to be backward compatible with its predecessors, and interface stability is always a priority at Docker.

In all cases, feature removal is communicated three releases in advance and documented as part of the deprecated features page.

The following list compiles any updates to Docker Engine that created backwards-incompatibility for old versions of Docker tools.

Note: In the case of your local environment, you should be updating your Docker Engine using Docker for Mac, Docker for Windows. That way all your tools stay in sync with Docker Engine.

Engine 1.10

There were two breaking changes in the 1.10 release that affected Registry and Docker Content Trust:

Registry

Registry 2.3 includes improvements to the image manifest that caused a breaking change. Images pushed by Engine 1.10 to a Registry 2.3 cannot be pulled by digest by older Engine versions. A docker pull that encounters this situation returns the following error:

 Error response from daemon: unsupported schema version 2 for tag TAGNAME

Docker Content Trust heavily relies on pull by digest. As a result, images pushed from the Engine 1.10 CLI to a 2.3 Registry cannot be pulled by older Engine CLIs (< 1.10) with Docker Content Trust enabled.

If you are using an older Registry version (< 2.3), this problem does not occur with any version of the Engine CLI; push, pull, with and without content trust work as you would expect.

Docker Content Trust

Engine older than the current 1.10 cannot pull images from repositories that have enabled key delegation. Key delegation is a feature which requires a manual action to enable.