README.containers

This mini test platform relies on Docker containers to get work
done.  It could use something else, if for example you wanted
to set up multiple vms with the appropriate hostnames and
entries in /etc/hosts on the system from which the testbed
will be launched.

How to get going with Docker containers

You should get a copy of the devenviron repo from
http://www.github.com/apergos/...

Cd into the repo, run ./build-dev-base.sh to build the base image
ariel/dev:base which you will customize for testing purposes.

Create a Dockerfile which builds an image on top of that with
the programs and configuration you will need for your test hosts.
Bear in mind that test data and scripts will b copied over
during the test phases so you should not add those in the
Dockerfile.  See Dockerfile.testimage.example for a sample.

Build your test image from that Dockerfile:
docker build -rm -t <your-name-here>/<name-of-test-suite> .

Set up a script for creating the containers from that image
if there are several; you may want to revisit your test
suite in the future and this will save you some headscratching
later.  The commands in the script for creating containers
look like this:
docker run -d -name <hostname-here> -v /sys/fs/selinux:/selinux:ro name-of-test-image:latest

Note that the hostname you provide here is actually a docker container tag;
docker creates containers with hostnames that are a random string of hex digits.
The container will have its hostname set to the tag when the test suite runs.

If you reuse these containers you can stop and start them manually by
docker start hostname
and
docker stop hostname

If you are done with your test suite forever or just need to reclaim
space or move the whole thing elsewhere, you can remove the docker
containers by
docker rm container-name
and you can remove the test image or any other image by
docker rmi image-name

In order to run your test suite, the containers must be running and you
should add their ips and container names to your local /etc/hosts; you
can do this by running
python setup-etc-hosts.py hostname1,hostname2,...
You must do this every time the containers are started up.

Once you've set up the etc hosts file on the local host from which
the test suite will be launched, you can of course ssh into the various
containers using their container names for hostnames.

When you are done testing and before shutting down or removing
the containers, you should remove those entries from /etc/hosts by
python setup-etc-hosts.py --clean hostname1,hostname2,...
This removes only the host ips corresponsing to the specific running
containers.

If you forget to do this and shut down or remove the containers, you won't be able
to remove the entries from /etc/hosts the nice way, so you can either
remove *all* entries added by setup-etc-hosts.py for those containers by
python setup-etc-hosts.py --cleanall hostname1,hostname2,...
or of course you can edit the file by hand.