Add documentation about OpenStack vendor data handling.

2 files changed, 30 insertions, 0 deletions

diff --git a/doc/rtd/topics/datasources.rst b/doc/rtd/topics/datasources.rst
index cc0d0ede..c090d808 100644
--- a/doc/rtd/topics/datasources.rst
+++ b/doc/rtd/topics/datasources.rst
@@ -177,6 +177,12 @@ OVF
 For now see: https://bazaar.launchpad.net/~cloud-init-dev/cloud-init/trunk/files/head:/doc/sources/ovf/
 
 ---------------------------
+OpenStack
+---------------------------
+
+.. include:: ../../sources/openstack/README.rst
+
+---------------------------
 Fallback/None
 ---------------------------
 
diff --git a/doc/sources/openstack/README.rst b/doc/sources/openstack/README.rst
new file mode 100644
index 00000000..8102597e
--- /dev/null
+++ b/doc/sources/openstack/README.rst
@@ -0,0 +1,24 @@
+*TODO*
+
+Vendor Data
+~~~~~~~~~~~
+
+The OpenStack metadata server can be configured to serve up vendor data
+which is available to all instances for consumption.  OpenStack vendor
+data is, generally, a JSON object.
+
+cloud-init will look for configuration in the ``cloud-init`` attribute
+of the vendor data JSON object. cloud-init processes this configuration
+using the same handlers as user data, so any formats that work for user
+data should work for vendor data.
+
+For example, configuring the following as vendor data in OpenStack would
+upgrade packages and install ``htop`` on all instances:
+
+.. sourcecode:: json
+
+    {"cloud-init": "#cloud-config\npackage_upgrade: True\npackages:\n - htop"}
+
+For more general information about how cloud-init handles vendor data,
+including how it can be disabled by users on instances, see
+https://bazaar.launchpad.net/~cloud-init-dev/cloud-init/trunk/view/head:/doc/vendordata.txt