Add new variables for customising the deployment image in Bifrost

Add new variables, ``kolla_bifrost_dib_elements_extra`` and
``kolla_bifrost_dib_env_vars_extra``, in
``${KAYOBE_CONFIG_PATH}/bifrost.yml`` for setting additional
``diskimage-builder`` elements and environment variables for the disk
image generated by Bifrost. Default elements and environment variables
are now respectively defined by ``kolla_bifrost_dib_elements_default``
and ``kolla_bifrost_dib_env_vars_default``.

Change-Id: I22ab15c42d8db772f1a64f325f9371860491ccfb

ansible/group_vars/all/bifrost

@@ -20,19 +20,31 @@ kolla_bifrost_dib_os_element: "centos7"
 # DIB image OS release.
 kolla_bifrost_dib_os_release: "GenericCloud"
 
-# List of DIB elements.
+# List of default DIB elements.
-kolla_bifrost_dib_elements:
+kolla_bifrost_dib_elements_default:
   - "disable-selinux"
   - "enable-serial-console"
   - "vm"
 
+# List of additional DIB elements.
+kolla_bifrost_dib_elements_extra: []
+
+# List of all DIB elements.
+kolla_bifrost_dib_elements: "{{ kolla_bifrost_dib_elements_default + kolla_bifrost_dib_elements_extra }}"
+
 # DIB init element.
 kolla_bifrost_dib_init_element: "cloud-init-datasources"
 
-# DIB environment variables.
+# DIB default environment variables.
-kolla_bifrost_dib_env_vars:
+kolla_bifrost_dib_env_vars_default:
   DIB_CLOUD_INIT_DATASOURCES: "ConfigDrive"
 
+# DIB additional environment variables.
+kolla_bifrost_dib_env_vars_extra: {}
+
+# DIB environment variables.
+kolla_bifrost_dib_env_vars: "{{ kolla_bifrost_dib_env_vars_default | combine(kolla_bifrost_dib_env_vars_extra) }}"
+
 # List of DIB packages to install.
 kolla_bifrost_dib_packages: []
 

etc/kayobe/bifrost.yml

@@ -20,12 +20,24 @@
 # DIB image OS release.
 #kolla_bifrost_dib_os_release:
 
+# List of default DIB elements.
+#kolla_bifrost_dib_elements_default:
+
+# List of additional DIB elements.
+#kolla_bifrost_dib_elements_extra:
+
 # List of DIB elements.
 #kolla_bifrost_dib_elements:
 
 # DIB init element.
 #kolla_bifrost_dib_init_element:
 
+# DIB default environment variables.
+#kolla_bifrost_dib_env_vars_default:
+
+# DIB additional environment variables.
+#kolla_bifrost_dib_env_vars_extra:
+
 # DIB environment variables.
 #kolla_bifrost_dib_env_vars:
 

releasenotes/notes/bifrost-dib-extra-c4eac903986ec700.yaml

@@ -0,0 +1,19 @@
+---
+features:
+  - |
+    Adds new variables, ``kolla_bifrost_dib_elements_extra`` and
+    ``kolla_bifrost_dib_env_vars_extra``, in
+    ``${KAYOBE_CONFIG_PATH}/bifrost.yml`` for setting additional
+    ``diskimage-builder`` elements and environment variables for the disk image
+    generated by Bifrost. Default elements and environment variables are now
+    respectively defined by ``kolla_bifrost_dib_elements_default`` and
+    ``kolla_bifrost_dib_env_vars_default``.
+upgrade:
+  - |
+    It is now possible to set additional ``diskimage-builder`` elements and
+    environment variables for the disk image generated by Bifrost, while
+    keeping defaults set by Kayobe. If your configuration overrides
+    ``kolla_bifrost_dib_elements`` or ``kolla_bifrost_dib_env_vars`` while
+    still including default values set in ``ansible/group_vars/all/bifrost``,
+    you can move your additions to ``kolla_bifrost_dib_elements_extra`` and
+    ``kolla_bifrost_dib_env_vars_extra`` instead.