Is it possible to share memory between docker containers?

The --ipc=host and --ipc=container:id options have since been added to the Docker create and run commands to share IPC resources.

--ipc=""  : Set the IPC mode for the container,
             'container:<name|id>': reuses another container's IPC namespace
             'host': use the host's IPC namespace inside the container

IPC with the host

docker run --ipc=host <image>

IPC with another container

docker run --ipc=container:<id> <image>

IPC with another container may need the shareable option set on the initial container (if dockerd defaults IPC to private)

docker run --ipc=shareable <image>