[QUESTION] Running with esm flag

[Cas du Plessis]

I know this is probably a long shot, but is there anyway of using the -r esm flag in an alpine container?

[Michael Hart]

Do you mean after installing this module? https://github.com/standard-things/esm

It should totally be possible – give it a shot!

[Cas du Plessis]

Thanks, @mhart.

Not sure what i'm missing. Here's what I've done:

Installed the module with npm install ems --save.

Then in index.js:

"use strict";

require = require("esm")(module/*, options*/)
module.exports = require("./server.js")

But, when I run the container (node ./index.js), I get: "Cannot find module 'esm'".

I have also tried using node -r esm ./index.js

[Michael Hart]

Is this in a Dockerfile? How have you set this up?

[Michael Hart]

It seems to work fine for me:

$ docker run --rm -it -w /app mhart/alpine-node:10 sh
/app # npm install esm
npm WARN saveError ENOENT: no such file or directory, open '/app/package.json'
npm notice created a lockfile as package-lock.json. You should commit this file.
npm WARN enoent ENOENT: no such file or directory, open '/app/package.json'
npm WARN app No description
npm WARN app No repository field.
npm WARN app No README data
npm WARN app No license field.

+ esm@3.0.84
added 1 package from 1 contributor and audited 1 package in 0.863s
found 0 vulnerabilities

/app # node
> require('esm')
esm enabled
> 

[Cas du Plessis]

@mhart ... okay, I got past that issue. But, now I'm getting "Cannot find module 'async'" when the server starts.

Just to recap, here's my setup:

package.json excerpt:

  "scripts": {
    "start": "node -r esm ./server.js"
  },
  "dependencies": {
    ...
    "esm": "^3.0.84",
    ...
  },
  "esm": {
    "mode": "all"
  }

Here's my Dockerfile:

FROM node:9.6-alpine

RUN addgroup -S car && \
  adduser -S -g car car

ENV SRC=/dist
ENV HOME=/home/car
ENV HOME_APP=$HOME/app
ENV NODE_ENV=production

COPY package*.json $HOME_APP/

ADD https://github.com/Yelp/dumb-init/releases/download/v1.1.1/dumb-init_1.1.1_amd64 /usr/local/bin/dumb-init

WORKDIR $HOME_APP

RUN \
  chown -R car:car $HOME/** /usr/local/ && \
  chmod +x /usr/local/bin/dumb-init && \
  npm install --silent --progress=false --production --unsafe-perm && \
  chown -R car:car $HOME/.npm && \
  chown -R car:car $HOME/.config && \
  chown -R car:car /usr/local/lib/node_modules && \
  chown -R car:car $HOME_APP/**

COPY $SRC/ $HOME_APP/

USER car

# ENTRYPOINT ["/usr/local/bin/dumb-init", "--"]

HEALTHCHECK CMD node healthcheck.js

CMD ["npm", "start"]

I'm not sure why it is looking for the async package - async/await should be native in node now, right?

[Cas du Plessis]

When I add npm install async --save, it works. But, I'm still unsure why I need this package?

[Cas du Plessis]

Never mind, there was a missed dependency in my script. Thanks for the help!