How to Secure Docker's TCP Socket With TLS
Docker’s API is completely unprotected by default except for filesystem permissions on its Unix socket. You should set up TLS when exposing the Docker API over TCP so Docker Engine and your clients can verify each others’ identity. Otherwise anyone with access to the TCP port could browse your Docker containers, start new ones, and run actions as root on your system.Read This Article on CloudSavvy IT ›

Docker’s API is completely unprotected by default except for filesystem permissions on its Unix socket. You should set up TLS when exposing the Docker API over TCP so Docker Engine and your clients can verify each others’ identity. Otherwise anyone with access to the TCP port could browse your Docker containers, start new ones, and run actions as root on your system.