d — the only tool you need within Circle CI for dealing with docker swarm
export D_RELEASE=0.4.4 # the latest one wget -O - https://raw.githubusercontent.com/f213/d/master/install.sh|sh
The is pre-alfa, so checkout built-in help
$ ./d Usage: ./d.py COMMAND <OPTIONS> Where COMMAND is one of the following: deploy-stack Deploy or update a stack, using docker stack deploy. update-image Update image for all services in the running stack. push-image Push previously built image to the dockerhub. build-image Build docker image and version in based on current HEAD commit.