Dockerfile File Example

The parameters Dockerfile

# ############ 主要用来构建镜像
FROM                # 指定镜像（必须有）
MAINTAINER      # 声明维护者（可有可无；位置无所谓，放在FROM后比较合理）
USER                 # 设置容器运行的UID（可有可无）
ENV                    # 指定环境变量（后续命令可以直接引用“$envname”）
RUN                    # 执行shell命令，用于创建容器（一般地，每条RUN对应一条命令；也可以利用 `；\`来执行多条命令）
# ############ 主要是用于构建镜像后的部署过程
COPY                 # 复制宿主机的文件到容器内
ADD                    # 添加宿主机的文件`或者URL`到容器内（和COPY基本相同，区别多了个下载网络文件）
VOLUME             # 将容器内的目录映射到宿主机内（方便在宿主机内查看文件，比如日志，项目源码等）
WORKDIR           # 工作目录，指明`CMD命令的运行目录`
ENTRYPOINT      # `只能有一个entrypoint存在，不可被docker run 命令的命令行参数覆盖`
EXPOSE              # 容器暴露的端口
CMD                    # 执行shell命令，`和RUN区别`：run用于部署，cmd用于部署运行，并且可以和entrypoint配合使用

Dockerfile some parameters may be covered with command line arguments

When we allow the deployment of dynamic input parameters, specify the parameters covered Dockefile

Specific examples of construction使用场景：2.

scenes to be used

1. Build docker image provided to other persons

Commonly used commands: docker build -t image_name:iamge_tag -f path/Dockerfile --rm ./app

2. The other person under docker image deployment project

Common Command: docker run -d -e -v -u -w -p image_name
Description: -d: background; -e: the specified environment variable; -v: volume within the container and mapping host directory; -u: UID specified operating container; -w: Specifies workdir; -p: designated port

Explanation

dockerfile almost always placed in the root directory of the project;
The project file docker project directory and configuration provided dockerfile provide independent environment constructing a project to deploy;
In general, we do not need to save docker image, because the Dockerfilemore easy to store and transfer, and more lightweight, easy to edit, consistent environment;
Sometimes order to more quickly deploy 节省构建的时间, you can save the image file docker, when running the container line operating parameters can be adjusted simply by command.