I’ve been working with Docker for about a few days and I confused with installing & running different extensions in Docker with composer.The main issue is that I can’t properly install compoer inside my php dockerfile & docker-compose.My goal is to install the composer itself and guzzle library for my running php & nginx docker container.
php dockerfile:

ENV COMPOSER_ALLOW_SUPERUSER=1
COPY --from=composer:latest /usr/bin/composer /usr/bin/composer
COPY ./src/composer.* ./
RUN composer install
COPY ./src .

docker-compose.yaml:

services:
  nginx:
    build:
      context: .
      dockerfile: nginx/Dockerfile
    ports:
      - "8080:80"
    networks:
      - internal
    volumes:
      - ./src/:/var/www/html/
      - ./logs/nginx:/var/log/nginx/
  php:
    build:
      context: .
      dockerfile: php/Dockerfile
    networks:
      - internal
    volumes:
      - ./src/:/var/www/html/
      - ./logs/php.log:/var/log/fpm-php.www.log
      - ./vendor/:/var/www/html/
      - ./composer.json/:/var/www/html/
      - ./composer.lock/:/var/www/html/
networks:
  internal:
    driver: bridge