Docker-compose: Set a variable in env file and use it in Dockerfile

Question

I'm using Docker and Docker-compose to build a stack of nginx+php.

I'm trying to set the timezone in my .env file and use it in a Dockerfile, but I might be missunderstanding something from the documentation.

.env

# Timezone
TIMEZONE=Europe/Madrid

docker-compose.yml

version '2'

services:
    php:
        build: php7-fpm
        volumes:
            - ${APP_PATH}:/var/www/app
            - ./logs:/var/www/logs
        environment:
            TIMEZONE: ${TIMEZONE}

#[...more.stuff...]

php7-fpm/Dockerfile

FROM php:7.0-fpm
ARG TIMEZONE

#[...more.stuff...]

ENV TIMEZONE=${TIMEZONE}
RUN ln -snf /usr/share/zoneinfo/$TIMEZONE /etc/localtime && echo $TIMEZONE > /etc/timezone
RUN printf '[PHP]\ndate.timezone = "%s"\n', $TIMEZONE > /usr/local/etc/php/conf.d/tzone.ini

The timezone is not set properly inside the container (running php --info | grep timezone inside the php container bash). If I write the zone manually in the Dockerfile, it works.

Answer 1

You need to pass the build argument in docker compose

version '2'

services:
    php:
        build: 
          dockerfile: php7-fpm
          args:
            TIMEZONE: ${TIMEZONE}
        volumes:
            - ${APP_PATH}:/var/www/app
            - ./logs:/var/www/logs

The environment are passed to the running container and not to the buildfile. For the you need to pass args in the build section