Using docker-compose to set containers timezones

Question

I have a docker-compose file running a few Dockerfiles to create my containers. I don't want to edit my Dockerfiles to set timezones because they could change at any time by members of my team and I have a docker-compose.override.yml file to make local environment changes. However, one of my containers (a Selenium based one) seems to not pull host time zone and that causes problems for me. Based on that I want to enforce timezones on all my containers. In my Dockerfiles right now I do

ENV TZ=America/Denver
RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone

And everything works fine. How do I replicate the same command in docker-compose syntax?

Answer 1

This is simple solution:

environment:
  - TZ=America/Denver

Answer 2

The easiest solution would be share volume in docker-compose.yml like this

ipchanger:
  image: codertarasvaskiv/ipchanger:raspberry
  volumes:
    - "/etc/localtime:/etc/localtime:ro"

• ro - means container can only read from /etc/localtime of host-machine.

Answer 3

version "2"

services:
  serviceA:
    ...
    environment:
      TZ: "America/Denver"
    command: >
      sh -c "ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && 
      echo $TZ > /etc/timezone &&
      exec my-main-application"

Edit: The question didn't ask for it but I've just added exec my-main-application to show how the main process would be specified. exec is important here to make sure that my-main-application receives Ctrl-C (SIGINT/SIGKILL).