OpenStack: Update documentation for custom os image urls

docs/dev/openstack/customization.md

@@ -13,6 +13,15 @@ export OPENSHIFT_INSTALL_OS_IMAGE_OVERRIDE="https://example.com/my-rhcos.qcow2"
 
 **NOTE:** For this to work, the environment variable value must be a valid http(s) URL.
 
+If the user wants to upload the image from the local file system, he can set the environment variable value as `file:///path/to/file`. In this case the installer will take this file and automatically create an image in Glance.
+
+Example:
+
+```sh
+export OPENSHIFT_INSTALL_OS_IMAGE_OVERRIDE="file:///home/user/rhcos.qcow2"
+./openshift-install create cluster --dir ostest
+```
+
 If the user wants to reuse an existing Glance image without any uploading of binary data, then it is possible to set `OPENSHIFT_INSTALL_OS_IMAGE_OVERRIDE` environment variable that specifies the Glance image name. In this case no new Glance images will be created, and the image will stay when the cluster is destroyed.
 
 Example:
@@ -22,4 +31,4 @@ export OPENSHIFT_INSTALL_OS_IMAGE_OVERRIDE="my-rhcos"
 ./openshift-install create cluster --dir ostest
 ```
 
-**NOTE:** The only difference in behavior with the previous example is that the value here is not an http(s) URL.
+**NOTE:** The only difference in behavior with the previous examples is that the value here is not an "http(s)" or "file" URL.

docs/user/openstack/customization.md

@@ -23,6 +23,7 @@ Beyond the [platform-agnostic `install-config.yaml` properties](../customization
 * `octaviaSupport` (optional string): Whether OpenStack supports Octavia (`1` for true or `0` for false)
 * `region` (deprecated string): The OpenStack region where the cluster will be created. Currently this value is not used by the installer.
 * `trunkSupport` (optional string): Whether OpenStack ports can be trunked (`1` for true or `0` for false)
+* `clusterOSimage` (optional string): Either a URL with `http(s)` or `file` scheme to override the default OS image for cluster nodes or an existing Glance image name.
 
 ## Machine pools
 
@@ -107,7 +108,17 @@ platform:
       clusterOSImage: http://mirror.example.com/images/rhcos-43.81.201912131630.0-openstack.x86_64.qcow2.gz?sha256=ffebbd68e8a1f2a245ca19522c16c86f67f9ac8e4e0c1f0a812b068b16f7265d
 ```
 
-If the user wants to reuse an existing Glance image without any uploading of binary data, then it is possible to set `clusterOSImage` install config parameter that specifies the Glance image name. In this case no new Glance images will be created, and the image will stay when the cluster is destroyed. In other words, if `clusterOSImage` is not an http(s) URL, then the installer will look into Glance for an image with that name.
+If the user wants to upload the image from the local file system, he can set `clusterOSImage` as `file:///path/to/file`. In this case the installer will take this file and automatically create an image in Glance.
+
+Example:
+
+```yaml
+platform:
+  openstack:
+      clusterOSImage: file:///home/user/rhcos.qcow2
+```
+
+If the user wants to reuse an existing Glance image without any uploading of binary data, then it is possible to set `clusterOSImage` install config parameter that specifies the Glance image name. In this case no new Glance images will be created, and the image will stay when the cluster is destroyed. In other words, if `clusterOSImage` is not an "http(s)" or "file" URL, then the installer will look into Glance for an image with that name.
 
 Example: