Add Using a different base image to image-building doc

TrivialFix Change-Id: Ic8e716aa2cfb4717c548ae6f9fecfbe367eb8845

Add Using a different base image to image-building doc
bcbf22c7 · Duong Ha-Quang · d10015db · bcbf22c7
Commit bcbf22c7 authored 8 years ago by Duong Ha-Quang
--- a/doc/image-building.rst
+++ b/doc/image-building.rst
@@ -223,6 +223,14 @@ append
 remove
    Remove a package from the default list.

+Using a different base image
+----------------------------
+
+Base-image can be specified by argument ``--base-image``. For example::
+
+    kolla-build --base-image registry.access.redhat.com/rhel7/rhel --base rhel
+
+
 Plugin Functionality
 --------------------