Merge https://github.com/coreos/coreos-cloudinit

Documentation/cloud-config.md

@@ -169,6 +169,7 @@ List of flannel configuration parameters:
 - **ip_masq**: Install IP masquerade rules for traffic outside of flannel subnet
 - **subnet_file**: Path to flannel subnet file to write out
 - **interface**: Interface (name or IP) that should be used for inter-host communication
+- **public_ip**: IP accessible by other nodes for inter-host communication
 
 [flannel-readme]: https://github.com/coreos/flannel/blob/master/README.md
 

Documentation/config-drive.md

@@ -21,6 +21,12 @@ mkisofs -R -V config-2 -o configdrive.iso /tmp/new-drive
 rm -r /tmp/new-drive
 ```
 
+If on OS X, replace the `mkisofs` invocation with:
+
+```sh
+hdiutil makehybrid -iso -joliet -default-volume-name config-2 -o configdrive.iso /tmp/new-drive
+```
+
 ## QEMU virtfs
 
 One exception to the above, when using QEMU it is possible to skip creating an