Node.js 使用2个基本映像时，在Dockerfile中传递环境变量不起作用

简而言之，我想在docker中构建一个带有web项目的容器，该项目的配置可以根据稍后在docker中运行映像时传递给它的参数进行修改

此项目尝试读取具有自定义属性的文件调用“environment.json”

我的Dockerfile是：

# NodeJS
FROM node:13.12.0-alpine as build

WORKDIR /app

ENV PATH /app/node_modules/.bin:$PATH

COPY dist /app/dist
COPY define-env.js /app
COPY environments.json /app

# I have changed this with a lot of possible solutions 
# that I have found in Internet, I tried everything.
# ARG APP_ENV
# ENV ENVIRONMENT $APP_ENV
RUN node define-env.js ${APP_ENV}

# NGINX
FROM nginx:stable-alpine
COPY --from=build /app/dist /usr/share/nginx/html
EXPOSE 80
CMD ["nginx", "-g", "daemon off;"]

我所做的是复制这两个：构建的基本web项目、负责编写正确环境的节点脚本和包含所有可能配置环境的JSON文件

节点脚本如下所示：

#!/usr/bin/env node

// we will need file system module to write the values
var fs = require("fs");
// this script is going to receive one parameter (see DockerFile)
var option = process.argv[2];
// taking all the possible configurations
var json = require("./environments.json");
// taking the chosen option (by default dev)
var environmentCfg = json[option] || json.dev;

// writing... It is important to do this task sync,
// because we need to be sure is finished before any step
fs.writeFileSync("./dist/environment.json", JSON.stringify(environmentCfg));

environments.json是这样的：

{
  "dev": {
    "title": "This is the dev environment",
    "anotherAttribute": "Hello dev, I was configured with Docker!"
  },
  "uat": {
    "title": "This is the uat environment",
    "anotherAttribute": "Hello uat, I was configured with Docker!"
  },
  "prod": {
    "title": "This is the prod environment",
    "anotherAttribute": "Hello prod, I was configured with Docker!"
  }
}

# I am taking a base image with NodeJS and Nginx
FROM hoosin/alpine-nginx-nodejs:latest
# Telling Docker I like to work in the app workdir
WORKDIR /app
# Copying all files I need
COPY dist /app/dist
COPY define-env.js /app
COPY environments.json /app

# My environment variable for runtime purposes (dev by devfault)
ENV APP_ENV dev

# Setup Nginx server
EXPOSE 80
CMD node define-env && mv ./dist/* /usr/share/nginx/html && nginx -g 'daemon off;'

我不知道在运行Docker映像时如何传递变量，我正在尝试以下操作：

docker build . -t docker-env

然后，创建映像后，我尝试使用以下命令运行它：

docker run -e APP_ENV=uat -it --rm -p 1337:80 docker-env

当我转到时，我总是看到“dev”配置

我已经检查过从DockerFile中删除NGINX配置，当我输入参数时，我可以看到它工作正常

我认为当我将baseImage从Node更改为Nginx时，会发生一些奇怪的事情（或者我不知道）

编辑：正如@babakabadkheir在评论中所建议的，我尝试了以下方法，但仍然失败：

FROM hoosin/alpine-nginx-nodejs:latest
WORKDIR /app

ENV PATH /app/node_modules/.bin:$PATH

COPY dist /app/dist
COPY define-env.js /app
COPY environments.json /app

RUN node define-env.js ${APP_ENV}
RUN mv ./dist/* /usr/share/nginx/html

EXPOSE 80
CMD ["nginx", "-g", "daemon off;"]

如果我看一看挂载的图像外壳，我可以看到它也放置了environment.json：

编辑2：

我已经像这样修改了Dockerfile，但它仍然不起作用：

# I am taking a base image with NodeJS and Nginx
FROM hoosin/alpine-nginx-nodejs:latest
# Telling Docker I like to work in the app workdir
WORKDIR /app
# Copying all files I need
COPY dist /app/dist
COPY define-env.js /app
COPY environments.json /app

# My environment variable for runtime purposes (dev by devfault)
ENV APP_ENV dev
# This instruction I think is failing, but when I swap it with
# CMD instead RUN and put a console.log works without troubles
RUN node define-env.js 

# Once I have all the files I move it to the Nginx workspace
RUN mv ./dist /usr/share/nginx/html

# Setup Nginx server
EXPOSE 80
CMD ["nginx", "-g", "daemon off;"]

现在，我的节点脚本如下所示：

#!/usr/bin/env node

var fs = require("fs");
// NOTE: this line is already taken via environment 
var option = process.env.APP_ENV;

var json = require("./environments.json");
var environmentCfg = json[option] || json.dev;
fs.writeFileSync("./dist/environment.json", JSON.stringify(environmentCfg));

最后一次编辑！ 终于有了

在CMD Docker说明中列出了我所有需要的解决方案：

CMD node define-env && mv ./dist/* /usr/share/nginx/html && nginx -g 'daemon off;'

---

您犯了两个错误：ENV与ARGS混合和语法错误

定义参数时，可以在生成图像时传递值，如果未指定，则使用默认值；然后读取Dockerfile上不带大括号的值： （注意：我使用了稍微不同的docker图像）

Dockerfile 现在，对于生成映像，必须指定APP_ENV参数值

建造 跑 ;太长，读不下去了 您的请求是在运行时指定配置，此问题有两种解决方案：

运行容器时使用ENVvar

当构建容器时使用ARGS

第一种解决方案有一个安全性的缺点，但其优点是分发一个映像：将整个文件从主机复制到容器，并在运行容器时传递正确的ENV值

第二个解决方案稍微复杂一些，不存在安全问题，但必须为每个配置构建单独的映像

第二个解决方案是已经编写好的答案，对于第一个解决方案，您必须在运行时简单地读取env变量

Dockerfile 建造 跑 代码 工具书类

---

解决方案是将运行时可修改的所有内容放入CMD指令中

正如我所经历的，RUN只在构建时第一次起作用，而CMD不起作用

因此，我在我的DockerFile中添加了：

CMD node define-env && mv ./dist/* /usr/share/nginx/html && nginx -g 'daemon off;'

我运行脚本，移动所有文件，然后为我的应用程序提供服务

我希望能在这方面帮助其他开发者，因为这对我来说是一种痛苦

TL；DR

总之，Dockerfile应该是这样的：

{
  "dev": {
    "title": "This is the dev environment",
    "anotherAttribute": "Hello dev, I was configured with Docker!"
  },
  "uat": {
    "title": "This is the uat environment",
    "anotherAttribute": "Hello uat, I was configured with Docker!"
  },
  "prod": {
    "title": "This is the prod environment",
    "anotherAttribute": "Hello prod, I was configured with Docker!"
  }
}

# I am taking a base image with NodeJS and Nginx
FROM hoosin/alpine-nginx-nodejs:latest
# Telling Docker I like to work in the app workdir
WORKDIR /app
# Copying all files I need
COPY dist /app/dist
COPY define-env.js /app
COPY environments.json /app

# My environment variable for runtime purposes (dev by devfault)
ENV APP_ENV dev

# Setup Nginx server
EXPOSE 80
CMD node define-env && mv ./dist/* /usr/share/nginx/html && nginx -g 'daemon off;'

---

检查此项：谢谢@Bababadkheir，但这不是我要找的。您正在尝试在图像中创建动态环境，然后您希望基于环境运行图像？没错，但您传递给我的内容我认为与此无关@Bababadkheiruse一个图像仅nginx。在dockerfile中手动安装nodejs并运行env脚本。这可能会有所不同，但这不是必须的

当您定义参数时，您必须在生成映像时传递值
。您可以使用默认值。您是对的，我更新了答案。@Max我对您的答案投了更高的票，因为您很好地解释了ARG和ENV之间的差异，但您的解决方案不适合我（请看我开发的edit 2解决方案）
docker build -t docker-generic .

docker run -d -p 8888:80 -e APP_ENV=uat docker-generic

# On your nodejs code you simply read the ENV value
// ....
var env = process.env.APP_ENV


CMD node define-env && mv ./dist/* /usr/share/nginx/html && nginx -g 'daemon off;'

# I am taking a base image with NodeJS and Nginx
FROM hoosin/alpine-nginx-nodejs:latest
# Telling Docker I like to work in the app workdir
WORKDIR /app
# Copying all files I need
COPY dist /app/dist
COPY define-env.js /app
COPY environments.json /app

# My environment variable for runtime purposes (dev by devfault)
ENV APP_ENV dev

# Setup Nginx server
EXPOSE 80
CMD node define-env && mv ./dist/* /usr/share/nginx/html && nginx -g 'daemon off;'