I have a simple docker-compose set up as follows.
version: \"3\"
services:
main:
image: python:3.5.2
entrypoint: /usr/bin/yes
network_mode: bridge
Credits to tgogos: I just had to use the non-default bridge.
For completeness, here is my working config.
version: "3"
services:
main:
networks:
test:
image: python:3.5.2
entrypoint: /usr/bin/yes
another:
networks:
test:
image: python:3.5.2
entrypoint: /usr/bin/yes
networks:
test:
driver: bridge
And the ping now works.
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
faa9f96d46a9 python:3.5.2 "/usr/bin/yes" 9 seconds ago Up 9 seconds dockerplayground_main_1
5b2d56ac0cd7 python:3.5.2 "/usr/bin/yes" 9 seconds ago Up 8 seconds dockerplayground_another_1
$ docker exec -it faa ping another
PING another (172.18.0.2): 56 data bytes
64 bytes from 172.18.0.2: icmp_seq=0 ttl=64 time=0.054 ms
64 bytes from 172.18.0.2: icmp_seq=1 ttl=64 time=0.047 ms
64 bytes from 172.18.0.2: icmp_seq=2 ttl=64 time=0.059 ms
64 bytes from 172.18.0.2: icmp_seq=3 ttl=64 time=0.066 ms