Pass variable to Dockerfile CMD, Nodejs - node.js

Question

I'm getting used to with Docker. Here is my current code in DockerFile:
FROM node:12-alpine AS builder
ARG NODE_ENV
ENV NODE_ENV ${NODE_ENV}
RUN npm run build
CMD ["sh","-c","./start-docker.sh ${NODE_ENV}"]
And I'm using pm2 to manage cluster in Nodejs, here is my start-docker.sh:
NODE_PATH=. pm2-runtime ./ecosystem.config.js --env $NODE_ENV
In my ecosystem.config.js, I define an env:
env_dev: {
NODE_ENV: 'development'
}
Everything is oke, but on my server, the NODE_ENV=''. I think there is something wrong when I pass in my CMD but can not find out what's wrong

Answer 1

Okay in my mind there is another way to do this, please try this way. this will not be actual code, it will just be an idea.
ecosystem.config.js
module.exports = {
apps : [{
name: "app",
script: "./app.js",
env: {
NODE_ENV: "development",
},
env_production: {
NODE_ENV: "production",
}
}]
}
And your dockerfile
dockerfile
FROM node:12-alpine
RUN npm run build
CMD ["pm2","start","ecosystem.config.js"]
As described in PM2 CLI documentation you just need to run command to start the application using the command pm2 start ecosystem.config.js this is automatically accessing the ENV variable described in ecosystem.config.js
https://pm2.keymetrics.io/docs/usage/application-declaration/#cli
Please try this, you might have new problems, but hope problems with some error logs, so that we can debug more. But I am sure that this could work and resolve your problem