Docker nodejs not found

Question

When i run docker build -t example . on the below im getting an error

FROM ruby:2.1
RUN rm /bin/sh && ln -s /bin/bash /bin/sh
ENV NVM_DIR /usr/local/nvm
ENV NODE_VERSION 4.4.2

RUN curl https://raw.githubusercontent.com/creationix/nvm/v0.31.0/install.sh | bash \
  && source $NVM_DIR/nvm.sh \
  && nvm install $NODE_VERSION \
  && nvm alias default $NODE_VERSION \
  && nvm use default


ENV NODE_PATH $NVM_DIR/v$NODE_VERSION/lib/node_modules
ENV PATH      $NVM_DIR/v$NODE_VERSION/bin:$PATH

RUN node -v

I get the following error:

Step 9 : RUN node -v ---> Running in 6e3fac36d2fc /bin/sh: node: command not found The command '/bin/sh -c node -v' returned a non-zero code: 127

Can't understand why node is not found in the path. i tried executing the nvm.sh file as well but it didnt have an effect.

Answer 1

Node version manager is an excellent application for switching versions of Node.js on your development machine, but Docker begs a specific kind of image/container design that is meant to be both ephemeral and stripped down to the bare essentials in order to support the "best practice" of microservices. Docker is just a fancy way to run a process, not a full VM. That last sentence has helped me a lot in how to think about Docker. And so here, you can make things easier on yourself by creating different versions of your image, instead of making one container with many versions of Node.js inside of it. This way, you can reference the Node version you want to run inside of your docker run command instead of trying to feed in environment variables trying to get NVM to select the right version. For example:

docker build -t=jamescharlesworth-node:4.x-latest .

And of course your Dockerfile will have in it the install command in your RUN directive that you mention in the comments:

RUN curl -sL https://deb.nodesource.com/setup_4.x | bash - 
RUN apt-get install -y nodejs