docker build + private NPM (+ private docker hub)

Question

I have an application which runs in a Docker container. It requires some private modules from the company's private NPM registry (Sinopia), and accessing these requires user authentication. The Dockerfile is FROM iojs:latest.

I have tried:

1) creating an .npmrc file in the project root, this actually makes no difference and npm seems to ignore it 2) using env variables for NPM_CONFIG_REGISTRY, NPM_CONFIG_USER etc., but the user doesn't log in.

Essentially, I seem to have no way of authenticating the user within the docker build process. I was hoping that someone might have run into this problem already (seems like an obvious enough issue) and would have a good way of solving it.

(To top it off, I'm using Automated Builds on Docker Hub (triggered on push) so that our servers can access a private Docker registry with the prebuilt images.)

Are there good ways of either: 1) injecting credentials for NPM at build time (so I don't have to commit credentials to my Dockerfile) OR 2) doing this another way that I haven't thought of ?

Answer 1

I found a somewhat elegant-ish solution in creating a base image for your node.js / io.js containers (you/iojs):

1. log in to your private npm registry with the user you want to use for docker
2. copy the .npmrc file that this generates

Example .npmrc:

registry=https://npm.mydomain.com/
username=dockerUser
[email protected]
strict-ssl=false
always-auth=true
//npm.mydomain.com/:_authToken="someAuthToken"

3. create a Dockerfile that copies the .npmrc file appropriately.

Here's my Dockerfile (based on iojs:onbuild):

FROM iojs:2.2.1

MAINTAINER YourSelf

# Exclude the NPM cache from the image
VOLUME /root/.npm

# Create the app directory
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app

# Copy npm config
COPY .npmrc /root/.npmrc

# Install app
ONBUILD COPY package.json /usr/src/app/
ONBUILD RUN npm install
ONBUILD COPY . /usr/src/app

# Run
CMD [ "npm", "start" ]

4. Make all your node.js/io.js containers FROM you/iojs and you're good to go.