docker and php: getting dependencies (composer) into the container

Question

A little context: I am new to docker and dont know of any best-practices yet. My task is to create a webservice based on php and i decided to use docker-compose for provisioning.

Because we are all fancy devs, we know - there is no way to build a php application without using composer these days.

My question:

Should i install dependencies in the build? So by adding this to my Dockerfile:

RUN cd /app && composer install --no-interaction --prefer-source --optimize-autoloader

Or should i install dependencies during development and build the container image with included dependencies?

---

I only know of one way NOT to do it: install dependencies locally on the dev machine and build the container afterwards. But how would the "best practice" look like?

And - because i am a newbee in this field - how would i run a "composer require some/package" for my app service container?

By the way

I also noticed a message "Do not run Composer as root/super user!" when building the container. I added COMPOSER_ALLOW_SUPERUSER=1 to my Env file (as seen here), but this message still appears.

Is it possible to NOT execute composer install as root in a docker container? Can i ignore that message?

Thanks in advance, Philipp

Answer 1

For the moment i am working towards the following solutuion:

Development environment:

Add the whole src as volume:

volumes:
  - .:/app

initial composer install command

docker-compose exec app composer install

install new composer package:

docker-compose exec app composer require some/package

The package will be installed via the container in your composer package directory (/vendor by default of course), the source code can be inspected in your ide, etc.

Production environment:

Only app state defined as volume, for example:

volumes:
  - public/uploads:/app/public/uploads

add /vendor to .dockerignore

and run composer install during build

RUN cd /app && composer install --no-dev --no-interaction --optimize-autoloader

So you will have a pre-built image to deploy, but still be able to develop in a more agile way.

There are still two downsides in this solution, maybe someone has input for me:

1) build becomes kind of slow - it seems composer caching does not work properly

A solution (i dont know if this is possible in composer) could be a volume for the composer cache directory.

2) all packages created by docker are owned by root, so you can only work on those files/folders with sudo/root session.

I have no idea how to fix this properly. Maybe i could create a user with the name of the dev user for the development container and have this user run commands and php-fpm, etc... For production root would be okay i guess.

I am still very new to docker and open for better solutions, so i wont accept this answer.

UPDATED

To add new user in docker user in Dockerfile. as follows

RUN useradd -ms /bin/bash  newuser
USER newuser

if you want to create home user too

WORKDIR /home/newuser

or

mkdir /home/newuser

if you want to back to root user, you can do like

USER root