`docker exec -it` equivalent in multi-node Docker Swarm context

docker_exec.sh

#!/usr/bin/env bash

docker_containerinfo() {
	local taskid=$(docker service ps -f desired-state=running -q $1)
	[[ -n "$taskid" ]] || { echo "no running task for service $1" >&2; return 1; }
	local containerinfo=($(docker inspect --format '{{.NodeID}} {{.Status.ContainerStatus.ContainerID}}' $taskid))
	local host=$(docker node ls -f id="${containerinfo[0]}" --format '{{.Hostname}}')
	echo "$host ${containerinfo[1]}"
}

docker_exec() {
	svc=$1
	shift
	info=$(docker_containerinfo $svc)
	(( $? == 0 )) || { return 1; }
	local containerinfo=($info)
	local host="${containerinfo[0]}"

	if [[ "$host" == $(hostname) ]] || [[ "$host" == "docker-desktop" ]]; then
	    hostflag=""
    else
        hostflag="-H ssh://$host"
    fi
    if [[ -n "$PS1" ]]; then
        iflag="i"
    else
        iflag=""
    fi
    docker $hostflag exec -${iflag}t ${containerinfo[1]} "$@"
    return $?
}

# usage:
# source docker_exec.sh
# docker_exec <service_name> <command> <args...>