How can I ping other containers in a docker network through their hostname?

Question

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
         


        

Answer 1

Another solution I tried and worked was explicitly linking the containing you want to ping with host name. For example, I have a postgres container, and a server wants to connect to it.

Run the server with the following

docker run --name server --link postgres someserver:latest

In the server container environment, you can then ping with (given postgres is on the same bridge/network and is running)

ping postgres 

Since --link has been deprecated, it is recommended to use network bridge.

docker network create YOURNETWORK
docker run --name postgres --network='YOURNETWORK' postgres:latest
docker run --name server --network='YOURNETWORK' server:latest

then the two containers can ping each other by name.