Just set qcow2 version

Simplify the diskimage-builder config options in the nodepool config by
removing qemu-img-options from nodepool's configuration. Instead we
hardcode a qcow2 version compat setting of 0.10. This is necessary for
HPCloud and possibly other clouds, and keeps things simple in nodepool.

Change-Id: Icbbb92e22e5cab1332c17291392162d3d86de6b5

doc/source/configuration.rst

@@ -170,7 +170,6 @@ will be built using the provider snapshot approach::
       - puppet
       - node-devstack
     release: precise
-    qemu-img-options: compat=0.10
     env-vars:
         DIB_DISTRIBUTION_MIRROR: http://archive.ubuntu.com
         DIB_IMAGE_CACHE: /opt/dib_cache
@@ -179,12 +178,9 @@ For diskimages, the `name` is required. The `elements` section
 enumerates all the elements that will be included when building the
 image, and will point to the `elements-dir` path referenced in the
 same config file. `release` specifies the distro to be used as a base
-image to build the image using diskimage-builder.  `qemu-img-options`
-allows to specify custom settings that qemu will be using to build the
-final image. Settings there have to be separated by commas, and must
-follow qemu syntax.  `env-vars` is an optional dictionary of arbitrary
-environment variables that will be available in the spawned
-diskimage-builder child process.
+image to build the image using diskimage-builder.  `env-vars` is an
+optional dictionary of arbitrary environment variables that will be
+available in the spawned diskimage-builder child process.
 
 providers
 ---------

nodepool/nodepool.py

@@ -54,6 +54,10 @@ IMAGE_CLEANUP = 8 * HOURS    # When to start deleting an image that is not
 DELETE_DELAY = 1 * MINS      # Delay before deleting a node that has completed
                              # its job.
 
+# HP Cloud requires qemu compat with 0.10. That version works elsewhere,
+# so just hardcode it for all qcow2 building
+DEFAULT_QEMU_IMAGE_COMPAT_OPTIONS = "--qemu-img-options 'compat=0.10'"
+
 
 class LaunchNodepoolException(Exception):
     statsd_key = 'error.nodepool'
@@ -763,20 +767,20 @@ class DiskImageBuilder(threading.Thread):
         for k, v in image.env_vars.items():
             env[k] = v
 
-        extra_options = ''
-        if image.qemu_img_options:
-            extra_options = ('--qemu-img-options %s' %
-                             image.qemu_img_options)
         img_elements = image.elements
         img_types = ",".join(image.image_types)
 
+        qemu_img_options = ''
+        if 'qcow2' in img_types:
+            qemu_img_options = DEFAULT_QEMU_IMAGE_COMPAT_OPTIONS
+
         if 'fake-' in filename:
             dib_cmd = 'nodepool/tests/fake-image-create'
         else:
             dib_cmd = 'disk-image-create'
 
         cmd = ('%s -x -t %s --no-tmpfs %s -o %s %s' %
-               (dib_cmd, img_types, extra_options, filename, img_elements))
+               (dib_cmd, img_types, qemu_img_options, filename, img_elements))
 
         log = logging.getLogger("nodepool.image.build.%s" %
                                 (image_name,))
@@ -1308,7 +1312,6 @@ class NodePool(threading.Thread):
                 # d-i-b, but might be untyped in the yaml and
                 # interpreted as a number (e.g. "21" for fedora)
                 d.release = str(diskimage.get('release', ''))
-                d.qemu_img_options = diskimage.get('qemu-img-options', '')
                 d.env_vars = diskimage.get('env-vars', {})
                 if not isinstance(d.env_vars, dict):
                     self.log.error("%s: ignoring env-vars; "