Image Description for Google Compute Engine

A virtual disk image which is able to boot in the Google Compute Engine cloud framework has to comply the following constraints:

KIWI NG type must be an expandable disk
Google Compute Engine init must be installed
Disk size must be set to 10G
Kernel parameters must allow for serial console

To meet this requirements update the KIWI NG image description as follows:

Software packages

Make sure to add the following packages to the package list

Note

Package names used in the following list matches the package names of the SUSE distribution and might be different on other distributions.
```
<package name="google-compute-engine-init"/>
```
Image Type definition

To allow the image to be expanded to the configured disk geometry of the instance started by Google Compute Engine it is suggested to let KIWI NG’s OEM boot code take over that task. It would also be possible to try cloud-init’s resize module but we found conflicts when two cloud init systems, google-compute-engine-init and cloud-init were used together. Thus for now we stick with KIWI NG’s boot code which can resize the disk from within the initrd before the system gets activated through systemd.

Update the oem image type setup to be changed into an expandable type as follows:
```
<type image="oem"
      initrd_system="dracut"
      filesystem="ext4"
      kernelcmdline="console=ttyS0,38400n8 net.ifnames=0"
      format="gce">
  <bootloader name="grub2" timeout="1"/>
  <size unit="M">10240</size>
  <oemconfig>
      <oem-resize>true</oem-resize>
      <oem-swap>false</oem-swap>
  </oemconfig>
</type>
```

An image built with the above setup can be uploaded into the Google Compute Engine cloud and registered as image. For further information on how to upload to Google see: google-cloud-sdk on software.opensuse.org