Support file injection on boot w/ Libvirt

Implementes bp libvirt-file-injection

Change-Id: I25a5cc1b2261726e9603349df323e29cd1ed31e8

2 files changed, 32 insertions, 0 deletions

diff --git a/nova/virt/disk/api.py b/nova/virt/disk/api.py
index 1cd697347..2c7e1a034 100644
--- a/nova/virt/disk/api.py
+++ b/nova/virt/disk/api.py
@@ -205,6 +205,21 @@ def inject_data(image, key=None, net=None, metadata=None,
         raise exception.Error(img.errors)
 
 
+def inject_files(image, files, partition=None, use_cow=False,
+                 disable_auto_fsck=True):
+    """Injects arbitrary files into a disk image"""
+    img = _DiskImage(image=image, partition=partition, use_cow=use_cow,
+                     disable_auto_fsck=disable_auto_fsck)
+    if img.mount():
+        try:
+            for (path, contents) in files:
+                _inject_file_into_fs(img.mount_dir, path, contents)
+        finally:
+            img.umount()
+    else:
+        raise exception.Error(img.errors)
+
+
 def setup_container(image, container_dir=None, use_cow=False):
     """Setup the LXC container.
 
@@ -251,6 +266,14 @@ def inject_data_into_fs(fs, key, net, metadata, execute):
         _inject_metadata_into_fs(metadata, fs, execute=execute)
 
 
+def _inject_file_into_fs(fs, path, contents):
+    absolute_path = os.path.join(fs, path.lstrip('/'))
+    parent_dir = os.path.dirname(absolute_path)
+    utils.execute('mkdir', '-p', parent_dir, run_as_root=True)
+    utils.execute('tee', absolute_path, process_input=contents,
+          run_as_root=True)
+
+
 def _inject_metadata_into_fs(metadata, fs, execute=None):
     metadata_path = os.path.join(fs, "meta.js")
     metadata = dict([(m.key, m.value) for m in metadata])
diff --git a/nova/virt/libvirt/connection.py b/nova/virt/libvirt/connection.py
index df0cd5725..04e10dd2b 100644
--- a/nova/virt/libvirt/connection.py
+++ b/nova/virt/libvirt/connection.py
@@ -718,6 +718,11 @@ class LibvirtConnection(driver.ComputeDriver):
         fp.write(data)
         return fpath
 
+    def _inject_files(self, instance, files):
+        disk_path = os.path.join(FLAGS.instances_path,
+                                 instance['name'], 'disk')
+        disk.inject_files(disk_path, files, use_cow=FLAGS.use_cow_images)
+
     @exception.wrap_exception()
     def get_console_output(self, instance):
         console_log = os.path.join(FLAGS.instances_path, instance['name'],
@@ -1065,6 +1070,10 @@ class LibvirtConnection(driver.ComputeDriver):
         if FLAGS.libvirt_type == 'uml':
             libvirt_utils.chown(basepath('disk'), 'root')
 
+        files_to_inject = inst.get('injected_files')
+        if files_to_inject:
+            self._inject_files(inst, files_to_inject)
+
     @staticmethod
     def _volume_in_mapping(mount_device, block_device_info):
         block_device_list = [block_device.strip_dev(vol['mount_device'])