How do I run commands in a Docker container inside an Azure pipeline?

I have a PHP application that is containerized. I am trying to set up a pipeline in Azure, but I am struggling to run commands inside the built container (which is essential to fully install & scaffold the application so that I can run code analysis and tests).

I have make commands set up, so the way to install the application is simply

make up
make install

These are effectively running:

docker-compose up --build -d
docker-compose exec -T {containerName} composer install
docker-compose exec -T {containerName} php artisan migrate:fresh
docker-compose exec -T {containerName} php artisan passport:install
docker-compose exec -T {containerName} php artisan db:seed
...

to build the image, install dependencies (laravel), scaffold the app backend.

My test azure-pipelines.yml is set up as follows:

# Docker
# Build a Docker image
# https://learn.microsoft.com/azure/devops/pipelines/languages/docker

trigger:
- develop

resources:
- repo: self

variables:
  tag: '$(Build.BuildId)'

stages:
- stage: Build
  displayName: Build image
  jobs:
  - job: Build
    displayName: Build
    pool:
      vmImage: ubuntu-latest
    steps:
      - task: Docker@2
        displayName: Build an image
        inputs:
          command: build
          dockerfile: '$(Build.SourcesDirectory)/infrastructure/php/Dockerfile'
          tags: |
            $(tag)
  - job: Install
    displayName: Install app
    dependsOn: Build
    steps:
    - script: |
        docker-compose exec -T api composer install
  - job: Database
    displayName: Scaffold Database
    dependsOn: Install
    steps:
    - script: |
        make db_reset
  - job: Analyse
    displayName: Analyse backend
    dependsOn: Database
    steps:
    - script: |
        make analyse
  - job: Test
    displayName: Run tests
    dependsOn: Analyse
    steps:
    - script: |
        php artisan test

but this fails on the Install job, the error log is as follows:

Starting: CmdLine
==============================================================================
Task         : Command line
Description  : Run a command line script using Bash on Linux and macOS and cmd.exe on Windows
Version      : 2.201.1
Author       : Microsoft Corporation
Help         : https://learn.microsoft.com/azure/devops/pipelines/tasks/utility/command-line
==============================================================================
Generating script.
Script contents:
docker-compose exec -T api composer install
========================== Starting Command Output ===========================
/usr/bin/bash --noprofile --norc /home/vsts/work/_temp/a440fb6a-e03b-4da2-b958-1fa3aefa2084.sh
##[error]Bash exited with code '1'.
Finishing: CmdLine

Verifying lock file contents can be installed on current platform.
Package operations: 163 installs, 0 updates, 0 removals

In Filesystem.php line 268:
                                                                  
  /var/www/app/vendor does not exist and could not be created. 

when trying to install composer dependencies after building the image. The setup is pretty standard.

Dockerfile

FROM php:8.1-apache

RUN apt update
RUN apt-get install -y --no-install-recommends 
    g++ 
    libicu-dev 
    libpq-dev 
    libzip-dev 
    libfreetype6-dev 
    libjpeg62-turbo-dev 
    libpng-dev 
    git 
    lsb-release 
    gnupg 
    zip

RUN docker-php-ext-install 
    intl 
    opcache 
    pdo 
    pdo_mysql 
    zip 
    exif 
    gd
RUN pecl install 
    pcov 
    xdebug


WORKDIR /var/www/app

RUN usermod -a -G www-data www-data
RUN chown root:root /var/www

RUN chown -R www-data:www-data /var/www/app
RUN chmod -R 755 /var/www/app
RUN mkdir /var/www/app/vendor
RUN chmod -R 775 /var/www/app/vendor
RUN chown -R www-data:www-data /var/www/app/vendor
RUN a2enmod rewrite

RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer

USER www-data

docker-compose

version: '3.8'

services:
  database:
    image: mysql:8.0
    container_name: database
    environment:
      - MYSQL_DATABASE=app
      - MYSQL_ROOT_PASSWORD=root
    volumes:
      - ./infrastructure/mysql-data:/var/lib/mysql
    ports:
      - '3306:3306'

  api:
    container_name: api
    build:
      context: ./infrastructure/php
    ports:
      - '8080:80'
    volumes:
      - ./server:/var/www/app
      - ./infrastructure/apache/default.conf:/etc/apache2/sites-enabled/000-default.conf
    depends_on:
      - database

  mailhog:
    image: mailhog/mailhog:latest
    container_name: mailhog
    ports:
      - '1025:1025'
      - '8025:8025'

Makefile

DOCKER_COMPOSE = docker-compose
COMPOSER ?= composer
PHP_CMD = php

PHP_SERVICE = api

up:
    @echo "n==> Docker container building and starting ..."
    $(DOCKER_COMPOSE) up --build -d

db_reset:
    $(DOCKER_COMPOSE) exec -T api php artisan migrate:fresh
    $(DOCKER_COMPOSE) exec -T api php artisan passport:install
    $(DOCKER_COMPOSE) exec -T api php artisan db:seed

analyse:
    $(DOCKER_COMPOSE) exec -T -u root api php artisan ide-helper:models -W
    $(DOCKER_COMPOSE) exec -T -u root api ./vendor/bin/php-cs-fixer fix app
    $(DOCKER_COMPOSE) exec -T -u root api ./vendor/bin/phpstan analyse --memory-limit=2G -c phpstan.neon

I am assuming the issue is with permissions when trying to run composer install through the container, but then, how do I actually use the container? There’s no permission issues locally. The building obviously succeeds, here’s the last snippet of the build job:

 ---> Running in b83b9f8e8010
All settings correct for using Composer
Downloading...
Composer (version 2.3.5) successfully installed to: /usr/local/bin/composer
Use it: php /usr/local/bin/composer

Removing intermediate container b83b9f8e8010
 ---> bc104ff13e89
Step 11/22 : USER www-data
 ---> Running in 200f01ed5b5f
Removing intermediate container 200f01ed5b5f
 ---> 2431fb9a77ae
Step 12/22 : LABEL com.azure.dev.image.build.buildnumber=20220509.10
 ---> Running in 8183d45902d5
Removing intermediate container 8183d45902d5
 ---> d1a9ed6d2dc6
Step 13/22 : LABEL com.azure.dev.image.build.builduri=vstfs:///Build/Build/14
 ---> Running in 316a03a492e7
Removing intermediate container 316a03a492e7
 ---> 8bd620fc9792
Step 14/22 : LABEL com.azure.dev.image.build.definitionname=REDACTED
 ---> Running in 75f66a32856a
Removing intermediate container 75f66a32856a
 ---> 4daf41f08c6c
Step 15/22 : LABEL com.azure.dev.image.build.repository.name=REDACTED
 ---> Running in 707ba3523e83
Removing intermediate container 707ba3523e83
 ---> 7084ad9947a7
Step 16/22 : LABEL com.azure.dev.image.build.repository.uri=REDACTED
 ---> Running in b08c87ff8818
Removing intermediate container b08c87ff8818
 ---> 83a6531aef80
Step 17/22 : LABEL com.azure.dev.image.build.sourcebranchname=develop
 ---> Running in 0d69670ee481
Removing intermediate container 0d69670ee481
 ---> 6389f09560dc
Step 18/22 : LABEL com.azure.dev.image.build.sourceversion=dab0a85595268c16a05c5292adc1e0340c13818f
 ---> Running in 3b58e7fe5640
Removing intermediate container 3b58e7fe5640
 ---> e495c2eeab89
Step 19/22 : LABEL com.azure.dev.image.system.teamfoundationcollectionuri=REDACTED
 ---> Running in 2e04a85c91b9
Removing intermediate container 2e04a85c91b9
 ---> 4570213d4e47
Step 20/22 : LABEL com.azure.dev.image.system.teamproject=REDACTED
 ---> Running in f4c914d2522c
Removing intermediate container f4c914d2522c
 ---> 0ee813e09dbf
Step 21/22 : LABEL image.base.digest=sha256:2891049f5a33bd4ac61ea28b4d4f9144468e50369b7bc29ff61e2dd3089f5bb6
 ---> Running in 564f498fb0c4
Removing intermediate container 564f498fb0c4
 ---> 039be559c0d4
Step 22/22 : LABEL image.base.ref.name=php:8.1-apache
 ---> Running in 60c373b879be
Removing intermediate container 60c373b879be
 ---> c10cb44c17d6
Successfully built c10cb44c17d6
Finishing: Build an image

… or, am I doing this completely wrong? Any help would be greatly appreciated.