Merge pull request #2729 from Fedosin/metadata_service

Bug 1777804: OpenStack: add Nova metadata service to the list of requirements

Author: openshift-merge-robot

docs/user/openstack/README.md

@@ -15,6 +15,7 @@ In addition, it covers the installation with the default CNI (OpenShiftSDN), as
     - [Swift](#swift)
     - [Disk Requirements](#disk-requirements)
     - [Neutron Public Network](#neutron-public-network)
+    - [Nova Metadata Service](#nova-metadata-service)
   - [OpenStack Credentials](#openstack-credentials)
   - [Standalone Single-Node Development Environment](#standalone-single-node-development-environment)
   - [Running The Installer](#running-the-installer)
@@ -156,6 +157,10 @@ openstack network list --long -c ID -c Name -c "Router Type"
 
 **NOTE:** If the `neutron` `trunk` service plug-in is enabled, trunk port will be created by default. For more information, please refer to [neutron trunk port](https://wiki.openstack.org/wiki/Neutron/TrunkPort).
 
+### Nova Metadata Service
+
+Nova [metadata service](https://docs.openstack.org/nova/latest/user/metadata.html#metadata-service) must be enabled and available at `http://169.254.169.254`. Currently the service is used to deliver Ignition config files to Nova instances and provide information about the machine to `kubelet`.
+
 ## OpenStack Credentials
 
 You must have a `clouds.yaml` file in order to run the installer. The installer will look for a `clouds.yaml` file in the following locations in order: