docker: having trouble running npm install after creating a new user

Question

So I have another follow-up question regarding installing a node.js-based framework under Docker on CoreOS, per this post.

So, because npm is finicky about installing from package.json via root, I've had to create a nonroot sudo user in order to install the package. This is what my Dockerfile currently looks like inside of our repo, building off of an ubuntu image:

# Install dependencies and nodejs
RUN apt-get update
RUN apt-get install -y python-software-properties python g++ make
RUN add-apt-repository ppa:chris-lea/node.js
RUN apt-get update
RUN apt-get install -y nodejs

# Install git
RUN apt-get install -y git

# Bundle app source
ADD . /src

# Create a nonroot user, and switch to it
RUN /usr/sbin/useradd --create-home --home-dir /usr/local/nonroot --shell /bin/bash nonroot
RUN /usr/sbin/adduser nonroot sudo
RUN chown -R nonroot /usr/local/
RUN chown -R nonroot /usr/lib/
RUN chown -R nonroot /usr/bin/
RUN chown -R nonroot /src

USER nonroot

# Install app source
RUN cd /src; npm install

I know that this is an inelegant way to do things, but I'm otherwise at a loss as to how to complete an npm install here. When I try the above, I get errors on all of the packages as they try to install:

 Error: Attempt to unlock [email protected], which hasn't been locked
     at unlock (/usr/lib/node_modules/npm/lib/cache.js:1304:11)
     at cb (/usr/lib/node_modules/npm/lib/cache.js:646:5)
     at /usr/lib/node_modules/npm/lib/cache.js:655:20
     at /usr/lib/node_modules/npm/lib/cache.js:1282:20
     at afterMkdir (/usr/lib/node_modules/npm/lib/cache.js:1013:14)
     at /usr/lib/node_modules/npm/node_modules/mkdirp/index.js:37:53
     at Object.oncomplete (fs.js:107:15)
 If you need help, you may report this *entire* log,
 including the npm and node versions, at:
     <http://github.com/npm/npm/issues>

 ...

Any thoughts as to how I should modify my Dockerfile? I can only assume that this is some permissioning issue having to do with the way that I've provisioned the nonroot user above that might be particular to the Docker framework; I have no problem doing this kind of thing on just a vanilla ubuntu install, albeit not from script.

Answer 1

so it turns out that this may be an issue with docker.

was able to get around this by switching from USER nonroot to RUN /bin/su nonroot instead, afterwards everything worked fine.