在 Google Cloud Run 使用 Dockerfile 时，ReactJS process.env.NODE_ENV 未设置为生产环境

Question

I have a ReactJS website that I am running in Google Cloud Run using Dockerfile.

The website in Google Cloud Run still shows the variable NODE_ENV to development, even after I have specified it to be production in my Dockerfile.

Dockerfile

FROM node:alpine 

# Set the working directory to /app inside the container
WORKDIR /app

# Copy app files
COPY . .

# Install dependencies (npm ci makes sure the exact versions in the lockfile gets installed)
RUN npm ci 

# Build the app
RUN npm run build

# Set the env to "production"
ENV NODE_ENV production

# Expose the port on which the app will be running (3000 is the default that `serve` uses)
EXPOSE 3000

# Start the app
RUN npm i
CMD ["npm", "run", "start"]

Login.js

import React, { useState, useEffect, useRef } from 'react';

export default function Login() {
  // Backend URL
  let backendURL = ""
  if(process.env.NODE_ENV == "development"){
    backendURL = "https://localhost:5000"
  }
  else{
    backendURL = "https://my-website.a.run.app"
  }

  return(
    <div>
      <p>Please Log in {process.env.NODE_ENV}</p>
    </div>
  )
}

This gives

Please Log in development

I have also tried to assign the variable as Enviroment variable by clicking "Edit and deploy new Revision":

Answer 1

For Google Cloud Run, environment variables are not set in the Dockerfile. They are set via the deployment command.

gcloud run deploy --set-env-vars[...]

Tip: The EXPOSE statement also does nothing in Google Cloud Run.