dockerfile：` `composer install --no-dev安装dev依赖项，然后立即删除它们

Question

我的docker-compose设置(我认为)做了一些奇怪的事情。

我正在从此composer.json安装

{
    "require-dev":  {
        "phpunit/phpunit":"~9.0",
        "squizlabs/php_codesniffer": "~3.0",
        "fzaninotto/faker": "~1.9"
    },
    "require": {
        "doctrine/orm": "2.7.2",
        "haydenpierce/class-finder": "0.4.2"
    },
    "autoload" : {
        "psr-4": {
            "WebApp\\": "src/"
         }
    },
    "autoload-dev" : {
        "psr-4": {
            "WebApp\\Tests\\" : "tests/"
        }
    }
}

我的dockerfile看起来像这样：

FROM php:7.4.4-apache

#Install git
RUN php -v
RUN apt-get update && apt-get install -y git
RUN apt-get install zip unzip
RUN docker-php-ext-install pdo pdo_mysql mysqli

#enable Ubuntu module 'URL rewrite'
RUN a2enmod rewrite

#Install Composer
RUN php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
RUN php composer-setup.php --install-dir=/usr/local/bin/ --filename=composer

#setup database secrets file
COPY db_secret.prod.php /etc/db_secret.prod.php

#Make php error log file
RUN touch /var/log/php-error.log
RUN chmod 755 /var/log/php-error.log

#copy across necessary files
COPY . /var/www/
RUN rm /var/www/db_secret.prod.php

#change root that server runs files from
RUN sed -i 's+/var/www/html+/var/www/src/html+i' /etc/apache2/sites-available/000-default.conf

#Install php testing
RUN cd .. && composer update && composer install --no-dev

#RUN cd .. && vendor/bin/doctrine orm:schema-tool:create

EXPOSE 80

当运行composer install时，我得到：

Step 15/16 : RUN cd .. && composer update && composer install --no-dev
 ---> Running in 2980b48bbbc0
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 55 installs, 0 updates, 0 removals
  - Installing ocramius/package-versions (1.8.0): Downloading (100%)         
  ...abridged for brevity...       
  - Installing fzaninotto/faker (v1.9.1): Downloading (100%)         
symfony/polyfill-intl-normalizer suggests installing ext-intl (For best performance)
symfony/polyfill-intl-grapheme suggests installing ext-intl (For best performance)
symfony/service-contracts suggests installing symfony/service-implementation
symfony/console suggests installing symfony/event-dispatcher
symfony/console suggests installing symfony/lock
symfony/console suggests installing symfony/process
symfony/console suggests installing psr/log (For using the console logger)
doctrine/cache suggests installing alcaeus/mongo-php-adapter (Required to use legacy MongoDB driver)
doctrine/orm suggests installing symfony/yaml (If you want to use YAML Metadata Mapping Driver)
sebastian/global-state suggests installing ext-uopz (*)
phpunit/php-invoker suggests installing ext-pcntl (*)
phpunit/php-code-coverage suggests installing ext-pcov (*)
phpunit/php-code-coverage suggests installing ext-xdebug (*)
phpunit/phpunit suggests installing ext-soap (*)
phpunit/phpunit suggests installing ext-xdebug (*)
Writing lock file
Generating autoload files
ocramius/package-versions: Generating version class...
ocramius/package-versions: ...done generating version class
37 packages you are using are looking for funding.
Use the `composer fund` command to find out more!
Loading composer repositories with package information
Installing dependencies from lock file
Package operations: 0 installs, 0 updates, 31 removals
  - Removing webmozart/assert (1.8.0)
 ...abridged for brevity...
  - Removing fzaninotto/faker (v1.9.1)
Generating autoload files
ocramius/package-versions: Generating version class...
ocramius/package-versions: ...done generating version class
19 packages you are using are looking for funding.
Use the `composer fund` command to find out more!

谁能告诉我为什么它会安装然后删除开发包，而不是在原始安装中省略它们？

dockerfile的容器是php744-apache

Answer 1

非常简单:运行composer update (这将更新软件包列表并安装它们)，然后运行composer install --no-dev。

出于好奇:只有在更新Docker镜像时才会这样做。这有什么好的原因吗？为什么不将图像和运行在该图像中的源代码解耦？