docker build error while copying source file to php container - php

Question

I'm trying to set up my symfony project in docker, and i'M struggling building the php container.
I've put all my source code in \var\www\app\
Here is an extract of my docker-compose.yml:
php:
build:
context: .
dockerfile: docker/php/Dockerfile
volumes:
- '/var/www/app:/var/www'
restart: on-failure
env_file:
- .env
user: 1000:1000
nginx:
image: nginx:1.19.0-alpine
restart: on-failure
volumes:
- '/var/www/app:/var/www'
- './docker/nginx/app.conf:/etc/nginx/conf.d/app.conf:ro'
ports:
- '80:80'
depends_on:
- php
here's the Dockerfile:
FROM composer:2.0 as composer
FROM php:7.4-fpm
RUN docker-php-ext-install pdo_mysql
RUN pecl install apcu
RUN apt-get update && \
apt-get install -y \
libzip-dev
RUN docker-php-ext-install zip
RUN docker-php-ext-enable apcu
WORKDIR /var/www
COPY --chown=1000:1000 var/www/app /var/www
RUN PATH=$PATH:/usr/src/app/vendor/bin:bin
RUN composer install --no-scripts --prefer-dist \
&& rm -rf "$(composer config cache-dir)" "$(composer config data-dir)"
and here's the error I get while trying to build the php container:
Step 9/11 : COPY --chown=1000:1000 var/www/app /var/www
ERROR: Service 'php' failed to build: COPY failed: stat /var/lib/docker/tmp/docker-builder883740312/var/www/app: no such file or directory
The problem, I guess, is that it tries to fetch file within the docker build folder instead of /var/www/app. I thought it was because of the context, and I've tried to change it but then it cannot find my Dockerfile anymore.
I don't see how to resolve this, yyet I have the feeling it is a veryy easy one...But I'm quite lost at the moment.
Thanks!

Answer 1

You try to COPY a folder at build time and then at runtime you replace the same by using a VOLUME in your docker-compose. Maybe the volume is not needed?
Regarding the error, docker expects your var folder to be at the same level as docker-compose.yml. If that is not the case and your var folder is in docker/php/, then that is what you have to set as context in your docker-compose.yml.
php:
build:
context: docker/php
dockerfile: Dockerfile
If the Dockerfile is in the context, you don't even need to declare it explicitly in the docker-compose.yml