Fix k8s builder to use the declared volume size

Fixes #1773

buildman/manager/executor.py

@@ -324,6 +324,7 @@ class KubernetesExecutor(BuilderExecutor):
 
   def _job_resource(self, build_uuid, user_data, coreos_channel='stable'):
     vm_memory_limit = self.executor_config.get('VM_MEMORY_LIMIT', '8G')
+    vm_volume_size = self.executor_config.get('VOLUME_SIZE', '32G')
 
     # Max values for this container
     container_limits = {
@@ -375,6 +376,7 @@ class KubernetesExecutor(BuilderExecutor):
                 'env': [
                   {'name': 'USERDATA', 'value': user_data},
                   {'name': 'VM_MEMORY', 'value': vm_memory_limit},
+                  {'name': 'VM_VOLUME_SIZE', 'value': vm_volume_size},
                 ],
                 'limits' : container_limits,
                 'requests' : container_requests,

buildman/qemu-coreos/start.sh

@@ -7,6 +7,8 @@ set -o nounset
 mkdir -p /userdata/openstack/latest
 echo "$USERDATA" > /userdata/openstack/latest/user_data
 
+qemu-img resize ./coreos_production_qemu_image.img "${VM_VOLUME_SIZE}"
+
 qemu-system-x86_64 \
         -enable-kvm \
         -cpu host \