node-simple-exemple-inject-vars-with-docker

Dockerfile

FROM node:12-alpine
ENV MYAPP_DB_URL=CHANGE_ME
EXPOSE 3000
WORKDIR /app
COPY package*.json ./
RUN npm install --production
COPY index.js ./
CMD ["node", "index.js"]

index.js

const app = require("express")();
const PORT = 3000;
app.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});

app.get("/", (req, res, next) => {
  res.json({
    user: "john doe",
    DB_URL: process.env.MYAPP_DB_URL,
    OTHER_URL: process.env.MYAPP_OTHER_URL,
  });
});

package.json

{
  "name": "depency-docker-js",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.17.1"
  }
}