README-GOOGLE-CLOUD

Limitations
------------
The current implementation of the Google Cloud building has a couple of
limitations.

First of all, Google's gcloud command line tool is required for
all functions (see https://developers.google.com/cloud/sdk/gcloud/).

Next, the controller machine is required to be authenticated with Google's cloud
system (see https://developers.google.com/cloud/sdk/gcloud/reference/auth/).

Third, the workers must be on a network which has the worker port
(port 9989 by default) open. This can be done by setting up a network and
using that network in the ProvisionGoogleVM builstep. Example commands to
set up a network:

gcloud compute networks create autobuilder-network
gcloud compute firewall-rules autobuilder-allow --network autobuilder-network \
    --allow tcp:8010 tcp:9989 tcp:80 tcp:22

This sets up a network that is suitable for both controllers and workers, as
it allows all default autobuilder connections, as well as ssh and http. The
key:value pair 'network':'autobuilder-network' can then be added to your
ProvisionGoogleVMs buildstep, allowing provisioned machines to connect to
controllers.

Fourth, additional workers must be added to yocto-controller/controller.cfg
with the format:
     BuildWorker("worker<N>", "<WORKER-PASSWORD>", max_builds=3)
where N is 0...however many workers you want and WORKER-PASSWORD is the default
password. For example, if I wanted to add three workers for the cloud builder:

    c['workers'] = [BuildWorker("example-worker", "eeieHim8V", max_builds=3),]

would be changed to this:

    c['workers'] = [BuildWorker("example-worker", "eeieHim8V", max_builds=3),
                    BuildWorker("worker0", "eeieHim8V", max_builds=3),
                    BuildWorker("worker1", "eeieHim8V", max_builds=3),
                    BuildWorker("worker2", "eeieHim8V", max_builds=3),]

Finally, the worker-init script is only an example and has a couple
limitations itself. It has only been tested for debian VMs and will likely not
work on others. Also, the <HOST_ADDR> and <PASS> fields will need to be
manually edited in it if your autobuilder was created before the addition of
the GoogleVM buildsteps or if the controller machine is behind a firewall.

HowTo
----------

Assuming that the limitations above have been dealt with, this will provision
one new VM and completely set it up, including connections

    {'ProvisionGoogleVMs':{
        'vmname':'autobuilder-worker-startup-test',
        'vmcount':1,
        'zone':'us-central1-a',
        'machine':'n1-standard-4',
        'disksize':'230GB',
        'startupscript':'/path/to/yocto-autobuilder/bin/worker-init',
        'network':'autobuilder-network'}}

And this will delete the entire VM when you are finished with it:

    {'DeleteGoogleVMs': {}}

Note that the current implementation of DeleteGoogleVM requires that its in the
same buildset as CreateGoogleVM.