I've recently moved my node.js app into a docker image and I'd like to run my tests inside the image. My mocha/node tests work fine but the Karma tests involve starting Chrome to run the tests and Chrome isn't installed in the container.

How do I go about addressing this?

• Install Chrome in the Container? Seems less than ideal as I don't want to ship Chrome to my production servers inside the container.
• Somehow allow it to connect to Chrome on the host?
• Create a new image that inherits from my app image and adds Chrome and other things?

Googling 'docker & karma' reveals docker images out there but I can't find instructions on how to think about the problem and the best approach.

I've recently moved my node.js app into a docker image and I'd like to run my tests inside the image. My mocha/node tests work fine but the Karma tests involve starting Chrome to run the tests and Chrome isn't installed in the container.

How do I go about addressing this?

• Install Chrome in the Container? Seems less than ideal as I don't want to ship Chrome to my production servers inside the container.
• Somehow allow it to connect to Chrome on the host?
• Create a new image that inherits from my app image and adds Chrome and other things?

Googling 'docker & karma' reveals docker images out there but I can't find instructions on how to think about the problem and the best approach.

• javascript
• docker
• karma-runner

• have a look at github./jfrazelle/dockerfiles/blob/master/chrome/stable/… about Chrome – user2915097 Commented Dec 15, 2015 at 10:09
• Thanks I've read the blog post behind that before but it doesn't clarify for me how to proceed in this case. – MichaelJones Commented Dec 15, 2015 at 10:43
• if you go with "Create a new image that inherits from my app image and adds Chrome and other things?", you will need supervisor docs.docker./engine/articles/using_supervisord or such (s6, runit, daemon tools...) to manager your processes – user2915097 Commented Dec 15, 2015 at 10:45

4 Answers 4

I've found this docker image to be an excellent starting point for running karma tests quickly inside a docker container on Concourse CI:

https://hub.docker./r/markadams/chromium-xvfb-js/

It contains node 6.x (latest) + npm and a headless chromium instance using X virtual framebuffer. Working great for me!

You can try this (tested in Alpine Linux):

Option 1

1. Ensure that the 9876 port is accessible from the host.

2. Install chromium:

    apk add chromium # NOT google-chrome-stable
   

3. Create a wrapper script that starts chromium-browser in headless mode:

    vi /usr/bin/google-chrome-stable
   

   Add the following lines:

    #!/bin/sh
   
    chromium \
    --no-sandbox \
    --headless \
    --disable-gpu \
    --remote-debugging-port=9222 \
    "$@"
   

4. Make it executable:

    chmod +x /usr/bin/google-chrome-stable
   

5. Run the tests in headless mode:

    ng test --browsers ChromeHeadless
   

Option 2

You can also run the browser in a virtual X Server called Xvfb:

5. Remove the --headless option in the /usr/bin/google-chrome-stable script.

6. Start the server and export the DISPLAY vairable:

    Xvfb :1 -ac -screen 0 1024x768x24 &
    export DISPLAY=:1
   

7. Run the tests:

    ng test
   

There is also protractor-runner project, and Karma is similar to running Protractor, and so you might be able to learn how to do it from that example. But, I prefer the suggestion to use chromium-xvfb-js image.

Use PhantomJS instead of Chrome. Karma has PhantomJS launcher.

PhantomJS based on Blink.

Install PhantomJS:

npm karma-phantomjs-launcher --save-dev

Add to Karma config:

module.exports = function(config) {
  config.set({
    browsers : ['PhantomJS']
  });
};

EDIT

Here is part od Dockerfile

ENV NODE_VERSION 0.12.7
ENV NPM_VERSION 3.5.1
ENV PHANTOM_JS phantomjs-1.9.8-linux-x86_64

# App and test
RUN set -x \
    && buildDeps='curl git bzip2 file libfreetype6 libfontconfig1 python-pip python-dev libpq-dev libmemcached-dev libzmq-dev libjpeg62-turbo-dev zlib1g-dev libtiff5-dev make g++ psmisc' \
    && apt-get update \
    && apt-get install -y $buildDeps --no-install-remends \
    && rm -rf /var/lib/apt/lists/* \
    && curl -SLO "https://bitbucket/ariya/phantomjs/downloads/$PHANTOM_JS.tar.bz2" \
    && tar xvjf $PHANTOM_JS.tar.bz2 \
    && mv $PHANTOM_JS /usr/local/share \
    && ln -sf /usr/local/share/$PHANTOM_JS/bin/phantomjs /usr/local/bin \
    && curl -SLO "https://nodejs/dist/v$NODE_VERSION/node-v$NODE_VERSION-linux-x64.tar.gz" \
    && curl -SLO "https://nodejs/dist/v$NODE_VERSION/SHASUMS256.txt.asc" \
    && gpg --verify SHASUMS256.txt.asc \
    && grep " node-v$NODE_VERSION-linux-x64.tar.gz\$" SHASUMS256.txt.asc | sha256sum -c - \
    && tar -xzf "node-v$NODE_VERSION-linux-x64.tar.gz" -C /usr/local --strip-ponents=1 \
    && rm "node-v$NODE_VERSION-linux-x64.tar.gz" SHASUMS256.txt.asc \
    && npm install -g npm@"$NPM_VERSION" grunt-cli \
    && npm install \
    && npm cache clear \
    && ./node_modules/.bin/bower install --allow-root \
    && npm test \
    && apt-get purge -y --auto-remove $buildDeps \
    && rm -rf /usr/local/bin/node /usr/local/bin/npm /usr/local/include/node /usr/local/lib/node_modules \
    && rm -rf /usr/local/share/$PHANTOM_JS /usr/local/bin/phantomjs

In this case Docker made one layer. In this layer

1. install libs and tools (debian jessie)
2. install PhantomJS
3. install NodeJS
4. run tests
5. remove libs and tools
6. remove NodeJS
7. remove PhantomJS

Tests are running and You don't have PhantomJS in production container.