Add sample for ssh keys

lektor/content/configure/contents.lr

@@ -29,6 +29,10 @@ The main configuration is **/etc/ucloud/ucloud.json**.
   documentation](https://python-etcd3.readthedocs.io/en/latest/usage.html)
   for details.
 
+Example configuration:
+
+
+
 ## etcd based configuration REFERENCE
 
 ### /ucloud-core/

lektor/content/contents.lr

@@ -20,5 +20,7 @@ Checkout how the [development of ucloud started](https://redmine.ungleich.ch/iss
 
 ## Documentation that we are working on right now
 
-* [How to install ucloud](/install)
+* [How to install ucloud](/install) (for sysadmins)
-* [How to configure ucloud](/configure)
+* [How to configure ucloud](/configure) (for sysadmins)
+* [How to create / develop images](/images) (for developers, TBD)
+* [How to use ucloud](/use) (for users, TBD)

lektor/content/images/contents.lr

@@ -0,0 +1,58 @@
+title: Operating System images for ucloud
+---
+body:
+
+**THIS SITE IS UNDER CONSTRUCTION**
+
+![under construction](/underconstruction.jpg)
+
+## Introduction
+
+OS images for ucloud only require two settings:
+
+* IPv6 auto configuration support
+* Using the metadata server for getting SSH keys
+
+There are further settings that images can or should support.
+
+## IPv6 auto configuration
+
+Networking in ucloud requires all OS images to support IPv6. Most
+operating systems support IPv6 out of the box, but there might be some
+tunings necessary, depending on the operating system.
+
+Images for ucloud need to assign themselves addresses using
+**router advertisements** as described in
+[RFC 4862](https://tools.ietf.org/html/rfc4862).
+
+Additionally they need to support setting DNS servers
+based on router advertisements as described in
+[RFC 6106](https://tools.ietf.org/html/rfc6106).
+
+## Metadata support
+
+On boot an image needs to be configured to allow access. For this
+purpose, ucloud supports using a meta data server. The meta data
+server is reachable by HTTP and can be resolved using DNS.
+
+The following sections list the available meta data.
+
+### SSH keys
+
+The keys that are configured by the user to access the booted OS can
+be accessed on **http://metadata/ssh-keys**. A Unix alike OS could use
+this information similar to the following code snippet:
+
+```
+tmp=$(mktemp)
+curl http://metadata/ssh-keys > "${tmp}"
+
+# Ensure directory exists
+mkdir -p ~/.ssh
+
+# Merge them
+cat ~/.ssh/authorized_keys >> "${tmp}"
+
+# Create unique list of keys
+sort "${tmp}" | uniq > ~/.ssh/authorized_keys
+```

lektor/content/install/contents.lr

@@ -64,6 +64,5 @@ python main.py
 ### ucloud-scheduler
 
 ```
-git clone https://code.ungleich.ch/ucloud/ucloud-api
+git clone https://code.ungleich.ch/ucloud/ucloud-scheduler
-
 ```