I'm trying to setup a Docker Swarm where containers comunicate using Overlay Network.
I'm simulating the infrastructure using 4 Raspberry Pi 3 Boards using HypriotOS 1.0.0 Linux distribution which include Docker Engine 1.12.1
After Swarm initialization ssh into manger node
# create one overlay network
$ docker network create --driver overlay swarm_network
# create first service (foo)
$ docker service create --replicas 1 --name foo --network swarm_network resin/rpi-raspbian tail -F -n0 /etc/hosts
# create second service (bar)
$ docker service create --replicas 1 --name bar --network swarm_network resin/rpi-raspbian tail -F -n0 /etc/hosts
# list services
$ docker service ls
ID            NAME  REPLICAS  IMAGE               COMMAND
aqhcndcdoaf4  bar   1/1       resin/rpi-raspbian  tail -F -n0 /etc/hosts
cylg7ws3egx7  foo   1/1       resin/rpi-raspbian  tail -F -n0 /etc/hosts
# find docker host running foo service
$ docker service ps foo
ID                         NAME   IMAGE               NODE     DESIRED  STATE  CURRENT STATE              ERROR
ed6z74ncz1zf0dqc7wph5huvk  foo.1  resin/rpi-raspbian  swarm-2  Running  Running about an hour ago
ssh into swarm-2 node
$docker ps
CONTAINER ID        IMAGE                       COMMAND                  CREATED             STATUS              PORTS               NAMES
78b0e421efcd        resin/rpi-raspbian:latest   "/usr/bin/entry.sh ta"   48 seconds ago      Up 45 seconds                           foo.1.ed6z74ncz1zf0dqc7wph5huvk
# exec into the running container 
$ docker exec -it foo.1.ed6z74ncz1zf0dqc7wph5huvk /bin/bash
# try dns resolution (OK)
root@78b0e421efcd:/# nslookup bar                                                                   
Server:     127.0.0.11
Address:    127.0.0.11#53
Non-authoritative answer:
Name:   bar
Address: 10.0.1.4
# ping bar service (FAIL) 
root@314b0ef6c82c:/# ping -c 1 bar
PING bar (10.0.1.4) 56(84) bytes of data.
From 314b0ef6c82c (10.0.1.3) icmp_seq=1 Destination Host Unreachable
--- bar ping statistics ---
1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms
I'm unable to ping my services what I'm doing wrong?