Docker image of Protractor with headless Chrome
Protractor end to end testing for AngularJS - dockerised with headless real Chrome.
Why headless Chrome?
PhantomJS is discouraged by Protractor creators and for a good reason. It's basically a bag of problems.
What is headless Chrome anyway?
To be perfectly honest - it is a real chrome running on xvfb. Therefore you have every confidence that the tests are run on the real thing.
docker run -it --privileged --rm --net=host -v /dev/shm:/dev/shm -v $(pwd):/protractor webnicer/protractor-headless [protractor options]
This will run protractor in your current directory, so you should run it in your tests root directory. It is useful to create a script, for example /usr/local/bin/protractor.sh such as this:
#!/bin/bash docker run -it --privileged --rm --net=host -v /dev/shm:/dev/shm -v $(pwd):/protractor webnicer/protractor-headless $@
The script will allow you to run dockerised protractor like so:
protractor.sh [protractor options]
Docker has hardcoded value of 64MB for
/dev/shm. Because of that you can encounter an error session deleted becasue of page crash on memory intensive pages. The easiest way to mitigate that problem is share
/dev/shm with the host.
This needs to be done till
docker build gets the option
Chrome uses sandboxing, therefore if you try and run Chrome within a non-privileged container you will receive the following message:
"Failed to move to new namespace: PID namespaces supported, Network namespace supported, but failed: errno = Operation not permitted".
--privileged flag gives the container almost the same privileges to the host machine resources as other processes running outside the container, which is required for the sandboxing to run smoothly.
This options is required only if the dockerised Protractor is run against localhost on the host. Imagine this sscenario: you run an http test server on your local machine, let's say on port 8000. You type in your browser
http://localhost:8000 and everything goes smoothly. Then you want to run the dockerised Protractor against the same localhost:8000. If you don't use
--net=host the container will receive the bridged interface and its own loopback and so the
localhost within the container will refer to the container itself. Using
--net=host you allow the container to share host's network stack and properly refer to the host when Protractor is run against
Why fork the original?
The original image is based off of node-slim, but I have some project dependencies that were broken by node's latest move up to 6.3.