How Do I Use an NPM Configuration File In an Intermediate Container?

Question

When trying to

docker build \
--tag my-app:latest \
.

with the following Dockerfile:

FROM node:9-stretch AS intermediate

ARG NPM_TOKEN

COPY [".npmrc", "./"]

RUN ["chmod", "0600", ".npmrc"]

COPY ["package.json", "./"]

RUN ["npm", "install"]

FROM node:9-stretch

WORKDIR /usr/src/app/

COPY --from=intermediate ["node_modules/.", "./node_modules/."]

COPY ["package.json", "index.js", "./"]

CMD ["node", "index.js"]

And the following .npmrc:

//registry.npmjs.org/:_authToken=${NPM_TOKEN}

I receive the following error during step Step 6/14 : RUN ["npm", "install"] of the intermediate container:

Error: Failed to replace env in config: ${NPM_TOKEN}
    at /usr/local/lib/node_modules/npm/lib/config/core.js:417:13
    at String.replace (<anonymous>)
    at envReplace (/usr/local/lib/node_modules/npm/lib/config/core.js:413:12)
    at parseField (/usr/local/lib/node_modules/npm/lib/config/core.js:391:7)
    at /usr/local/lib/node_modules/npm/lib/config/core.js:334:17
    at Array.forEach (<anonymous>)
    at Conf.add (/usr/local/lib/node_modules/npm/lib/config/core.js:333:23)
    at ConfigChain.addString (/usr/local/lib/node_modules/npm/node_modules/config-chain/index.js:244:8)
    at Conf.<anonymous> (/usr/local/lib/node_modules/npm/lib/config/core.js:321:10)
    at /usr/local/lib/node_modules/npm/node_modules/graceful-fs/graceful-fs.js:78:16
    at FSReqWrap.readFileAfterClose [as oncomplete] (fs.js:525:3)
/usr/local/lib/node_modules/npm/lib/npm.js:61
      throw new Error('npm.load() required')
      ^

Error: npm.load() required
    at Object.get (/usr/local/lib/node_modules/npm/lib/npm.js:61:13)
    at process.errorHandler (/usr/local/lib/node_modules/npm/lib/utils/error-handler.js:205:18)
    at process.emit (events.js:180:13)
    at process._fatalException (internal/bootstrap/node.js:391:27)

I also have the following line in my .bashrc for my Bash shell and .zshrc for my Z shell:

export NPM_TOKEN=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

I am adding the node_modules to my Docker Image in this fashion in accordance with the official NPM documentation found here.

Answer 1

You're almost there!

According to the official NPM documentation you linked, all you're missing from your docker build command is the --build-arg option, mentioned here and detailed here.

Your finished command should be:

docker build \
--build-arg NPM_TOKEN=${NPM_TOKEN} \
--tag my-app:latest \
.