doc: Add documentation for AliYun datasource.

Just add some documentation to readthedocs for AliYun.

2 files changed, 75 insertions, 0 deletions

diff --git a/doc/rtd/topics/datasources.rst b/doc/rtd/topics/datasources.rst
index 7e2854de..38ba75d8 100644
--- a/doc/rtd/topics/datasources.rst
+++ b/doc/rtd/topics/datasources.rst
@@ -80,6 +80,7 @@ Follow for more information.
 .. toctree::
    :maxdepth: 2
 
+   datasources/aliyun.rst
    datasources/altcloud.rst
    datasources/azure.rst
    datasources/cloudsigma.rst
diff --git a/doc/rtd/topics/datasources/aliyun.rst b/doc/rtd/topics/datasources/aliyun.rst
new file mode 100644
index 00000000..3f4f40ca
--- /dev/null
+++ b/doc/rtd/topics/datasources/aliyun.rst
@@ -0,0 +1,74 @@
+.. _datasource_aliyun:
+
+Alibaba Cloud (AliYun)
+======================
+The ``AliYun`` datasource reads data from Alibaba Cloud ECS.  Support is
+present in cloud-init since 0.7.9.
+
+Metadata Service
+----------------
+The Alibaba Cloud metadata service is available at the well known url
+``http://100.100.100.200/``. For more information see
+Alibaba Cloud ECS on `metadata
+<https://www.alibabacloud.com/help/zh/faq-detail/49122.htm>`__.
+
+Versions
+^^^^^^^^
+Like the EC2 metadata service, Alibaba Cloud's metadata service provides
+versioned data under specific paths.  As of April 2018, there are only
+``2016-01-01`` and ``latest`` versions.
+
+It is expected that the dated version will maintain a stable interface but
+``latest`` may change content at a future date.
+
+Cloud-init uses the ``2016-01-01`` version.
+
+You can list the versions available to your instance with:
+
+.. code-block:: shell-session
+
+    $ curl http://100.100.100.200/
+    2016-01-01
+    latest
+
+Metadata
+^^^^^^^^
+Instance metadata can be queried at
+``http://100.100.100.200/2016-01-01/meta-data``
+
+.. code-block:: shell-session
+
+    $ curl http://100.100.100.200/2016-01-01/meta-data
+    dns-conf/
+    eipv4
+    hostname
+    image-id
+    instance-id
+    instance/
+    mac
+    network-type
+    network/
+    ntp-conf/
+    owner-account-id
+    private-ipv4
+    public-keys/
+    region-id
+    serial-number
+    source-address
+    sub-private-ipv4-list
+    vpc-cidr-block
+    vpc-id
+
+Userdata
+^^^^^^^^
+If provided, user-data will appear at
+``http://100.100.100.200/2016-01-01/user-data``.
+If no user-data is provided, this will return a 404.
+
+.. code-block:: shell-session
+
+    $ curl http://100.100.100.200/2016-01-01/user-data
+    #!/bin/sh
+    echo "Hello World."
+
+.. vi: textwidth=78