告别Dockerfile，拥抱 docker init 构建Docker镜像

概述

Docker 是一个开源的应用容器引擎，它允许开发者打包他们的应用以及依赖包到一个可移植的容器中，然后发布到任何流行的 Linux 机器上，也可以实现虚拟化。容器是完全使用沙箱机制，相互之间不会有任何接口，更重要的是容器性能开销极低。

什么是 docker init？

docker init是一个命令行应用程序，可帮助初始化项目中的 Docker 资源。它根据项目的要求创建 Dockerfiles、docker-compose文件和 .dockerignore文件。这简化了为项目配置 Docker 的过程，节省时间并降低复杂性。

最新版本的 docker init支持 Go、Python、Node.js、Rust、ASP.NET、PHP和 Java。目前它只能于 Docker Desktop一起使用，也就是说大家目前在 Linux 系统中是无法使用 docker init的。

如何使用

使用 docker init很简单，只需几个简单的步骤。首先，转到您要在其中设置 Docker 资源的项目目录。

举个例子，我来创建一个基本的 PHP 应用程序。

创建 index.php <?php echo Hello World! 开源技术小栈！; 初始化

docker init将扫描您的项目并要求您确认并选择最适合您的应用程序的模板。选择模板后docker init会要求您提供一些特定于项目的信息，自动为您的项目生成必要的 Docker 资源。

接下来要做的就是选择应用程序平台，在示例中使用 PHP。它将建议您的项目的推荐值，例如 PHP 版本、端口、入口点命令。

您可以选择默认值或提供所需的值，它将创建您的 docker 配置文件以及动态运行应用程序的说明。让我们来看看这个自动生成的配置是什么样子。

$ ls Dockerfile README.Docker.md compose.yaml index.php 生成 Dockerfile 文件 # syntax=docker/dockerfile:1 # Comments are provided throughout this file to help you get started. # If you need more help, visit the Dockerfile reference guide at # https://docs.docker.com/go/dockerfile-reference/ ################################################################################ # The example below uses the PHP Apache image as the foundation for running the app. # By specifying the “7.4.28-apache” tag, it will also use whatever happens to be the # most recent version of that tag when you build your Dockerfile. # If reproducability is important, consider using a specific digest SHA, like # php@sha256:99cede493dfd88720b610eb8077c8688d3cca50003d76d1d539b0efc8cca72b4. FROM php:7.4.28-apache # Copy app files from the app directory. COPY . /var/www/html # Your PHP application may require additional PHP extensions to be installed # manually. For detailed instructions for installing extensions can be found, see # https://github.com/docker-library/docs/tree/master/php#how-to-install-more-php-extensions # The following code blocks provide examples that you can edit and use. # # Add core PHP extensions, see # https://github.com/docker-library/docs/tree/master/php#php-core-extensions # This example adds the apt packages for the gd extensions dependencies and then # installs the gd extension. For additional tips on running apt-get: # https://docs.docker.com/go/dockerfile-aptget-best-practices/ # RUN apt-get update && apt-get install -y # libfreetype-dev # libjpeg62-turbo-dev # libpng-dev # && rm -rf /var/lib/apt/lists/* # && docker-php-ext-configure gd –with-freetype –with-jpeg # && docker-php-ext-install -j$(nproc) gd # # Add PECL extensions, see # https://github.com/docker-library/docs/tree/master/php#pecl-extensions # This example adds the redis and xdebug extensions. # RUN pecl install redis-5.3.7 # && pecl install xdebug-3.2.1 # && docker-php-ext-enable redis xdebug # Use the default production configuration for PHP runtime arguments, see # https://github.com/docker-library/docs/tree/master/php#configuration RUN mv “$PHP_INI_DIR/php.ini-production” “$PHP_INI_DIR/php.ini” # Switch to a non-privileged user (defined in the base image) that the app will run under. # See https://docs.docker.com/go/dockerfile-user-best-practices/ USER www-data

它遵循人们在所有 Linkedin 和 Medium 帖子中不断告诉我们的所有性能和安全最佳实践。

docker-compose.yml # Comments are provided throughout this file to help you get started. # If you need more help, visit the Docker compose reference guide at # https://docs.docker.com/go/compose-spec-reference/ # Here the instructions define your application as a service called “server”. # This service is built from the Dockerfile in the current directory. # You can add other services your application may depend on here, such as a # database or a cache. For examples, see the Awesome Compose repository: # https://github.com/docker/awesome-compose services: server: build: context: . ports: – 9009:80 # The commented out section below is an example of how to define a PostgreSQL # database that your application can use. `depends_on` tells Docker Compose to # start the database before your application. The `db-data` volume persists the # database data between container restarts. The `db-password` secret is used # to set the database password. You must create `db/password.txt` and add # a password of your choosing to it before running `docker-compose up`. # depends_on: # db: # condition: service_healthy # db: # image: postgres # restart: always # user: postgres # secrets: # – db-password # volumes: # – db-data:/var/lib/postgresql/data # environment: # – POSTGRES_DB=example # – POSTGRES_PASSWORD_FILE=/run/secrets/db-password # expose: # – 5432 # healthcheck: # test: [ “CMD”, “pg_isready” ] # interval: 10s # timeout: 5s # retries: 5 # volumes: # db-data: # secrets: # db-password: # file: db/password.txt

它编写了 docker-compose.yaml配置来运行应用程序。由于我们的应用程序不包含与数据库的任何连接，因此它注释掉了数据库容器可能需要的代码。

构建镜像 docker compose up –build

运行容器 [+] Running 1/1 ✔ Container init-server-1 Recreated 0.2s Attaching to server-1 server-1 | AH00558: apache2: Could not reliably determine the servers fully qualified domain name, using 172.19.0.2. Set the ServerName directive globally to suppress this message server-1 | AH00558: apache2: Could not reliably determine the servers fully qualified domain name, using 172.19.0.2. Set the ServerName directive globally to suppress this message server-1 | [Wed Apr 17 15:36:35.110763 2024] [mpm_prefork:notice] [pid 1] AH00163: Apache/2.4.53 (Debian) PHP/7.4.28 configured — resuming normal operations server-1 | [Wed Apr 17 15:36:35.110809 2024] [core:notice] [pid 1] AH00094: Command line: apache2 -D FOREGROUND server-1 | 172.19.0.1 – – [17/Apr/2024:15:36:39 +0000] “GET / HTTP/1.1” 200 208 “-” “curl/7.70.0” server-1 | 172.19.0.1 – – [17/Apr/2024:15:37:18 +0000] “GET / HTTP/1.1” 200 208 “-” “curl/7.70.0” server-1 | 172.19.0.1 – – [17/Apr/2024:15:37:19 +0000] “GET / HTTP/1.1” 200 208 “-” “curl/7.70.0” server-1 | 172.19.0.1 – – [17/Apr/2024:15:37:19 +0000] “GET / HTTP/1.1” 200 208 “-” “curl/7.70.0” 请求访问 $ curl http://127.0.0.1:9009/ Hello World ! $ curl http://127.0.0.1:9009/ Hello World! 开源技术小栈！ 为什么使用 docker init？

docker init使 Docker 化变得轻而易举，特别是对于 Docker 新手来说。它消除了编写 Dockerfile和其他配置文件的手动任务，从而节省时间并最大限度地减少错误。它使用模板根据您的应用程序类型自定义 Docker 设置，同时遵循行业最佳实践。返回搜狐，查看更多

责任编辑：