Chrome not captured when using karma with Docker - node.js

Question

I am trying to run some karma tests using chrome in a Docker container. My Dockerfile looks like:
FROM node:6-alpine
RUN apk update \
&& apk add --update alpine-sdk \
&& apk add chromium \
&& npm install -g #angular/cli#1.0.0 \
&& ng set --global packageManager=yarn \
&& apk del alpine-sdk \
&& rm -rf /tmp/* /var/cache/apk/* *.tar.gz ~/.npm \
&& npm cache clear \
&& sed -i -e "s/bin\/ash/bin\/sh/" /etc/passwd
ENV CHROME_BIN=/usr/local/bin/my-chrome-build
When I run ng test in this container (having mounted a project which I know works), I get:
$ ng test -sr && yarn run test:server
04 04 2017 10:32:27.896:INFO [karma]: Karma v1.5.0 server started at http://0.0.0.0:9876/
04 04 2017 10:32:27.915:INFO [launcher]: Launching browser Chrome with unlimited concurrency
04 04 2017 10:32:27.985:INFO [launcher]: Starting browser Chrome
04 04 2017 10:33:28.047:WARN [launcher]: Chrome have not captured in 60000 ms, killing.
04 04 2017 10:33:30.053:WARN [launcher]: Chrome was not killed in 2000 ms, sending SIGKILL.
04 04 2017 10:33:32.056:WARN [launcher]: Chrome was not killed by SIGKILL in 2000 ms, continuing.
error Command failed with exit code 1.
I don't really know how to debug this, any ideas what might be wrong or how I can find out more?

Answer 1

I'm using Chrome headless unstable in a Docker container with the following Karma browser config (excerpt):
...
browsers: ['Chrome_in_Docker'],
customLaunchers: {
Chrome_in_Docker: {
base: 'ChromeHeadless',
flags: [
'--disable-web-security',
'--no-sandbox',
'--disable-setuid-sandbox',
'--disable-dev-shm-usage',
'--remote-debugging-port=9223',
'--headless',
'--disable-gpu'
]
}
},
...