Access container from service on other node in Docker Swarm

I have Docker running in swarm mode, and created a service that runs one container. The service my-service runs on node1 (Manager node), and the container my-container is spawned on node2

From node1, how can I make a docker exec on the my-container running on node2 ?

Solution

I found this project, skopos-plugin-swarm-exec, that solves my issue.

It can be used like this:

docker run -v /var/run/docker.sock:/var/run/docker.sock datagridsys/skopos-plugin-swarm-exec task-exec --image <task id> <command>

How It Works (Internals)
Starting from a task ID and a command to execute, here are the steps that are taken:

Obtain the node ID on which the target task is running, as well as the container ID of the task on that node
Create a temporary service, using the same container image, and a scheduling constraint that places the task of the temporary service on the same node where the target task is
Execute the equivalent of a docker exec command using the node-local Docker engine API
Upon completion of the command, terminate the temporary service, propagating the exit code of the executed command
Upon termination of the temporary service, extract the exit code and return it