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Diffstat (limited to 'doc/rtd/topics/format.rst')
| -rw-r--r-- | doc/rtd/topics/format.rst | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/doc/rtd/topics/format.rst b/doc/rtd/topics/format.rst index 1dd92309..5898d17a 100644 --- a/doc/rtd/topics/format.rst +++ b/doc/rtd/topics/format.rst @@ -1,18 +1,18 @@ -======= +******* Formats -======= +******* User data that will be acted upon by cloud-init must be in one of the following types. Gzip Compressed Content ------------------------ +======================= Content found to be gzip compressed will be uncompressed. The uncompressed data will then be used as if it were not compressed. This is typically is useful because user-data is limited to ~16384 [#]_ bytes. Mime Multi Part Archive ------------------------ +======================= This list of rules is applied to each part of this multi-part file. Using a mime-multi part file, the user can specify more than one type of data. @@ -31,7 +31,7 @@ Supported content-types: - text/cloud-boothook Helper script to generate mime messages -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +--------------------------------------- .. code-block:: python @@ -59,14 +59,14 @@ Helper script to generate mime messages User-Data Script ----------------- +================ Typically used by those who just want to execute a shell script. Begins with: ``#!`` or ``Content-Type: text/x-shellscript`` when using a MIME archive. Example -~~~~~~~ +------- :: @@ -78,7 +78,7 @@ Example $ euca-run-instances --key mykey --user-data-file myscript.sh ami-a07d95c9 Include File ------------- +============ This content is a ``include`` file. @@ -89,7 +89,7 @@ Ie, the content read from the URL can be gzipped, mime-multi-part, or plain text Begins with: ``#include`` or ``Content-Type: text/x-include-url`` when using a MIME archive. Cloud Config Data ------------------ +================= Cloud-config is the simplest way to accomplish some things via user-data. Using cloud-config syntax, the user can specify certain things in a human friendly format. @@ -109,14 +109,14 @@ See the :ref:`yaml_examples` section for a commented set of examples of supporte Begins with: ``#cloud-config`` or ``Content-Type: text/cloud-config`` when using a MIME archive. Upstart Job ------------ +=========== Content is placed into a file in ``/etc/init``, and will be consumed by upstart as any other upstart job. Begins with: ``#upstart-job`` or ``Content-Type: text/upstart-job`` when using a MIME archive. Cloud Boothook --------------- +============== This content is ``boothook`` data. It is stored in a file under ``/var/lib/cloud`` and then executed immediately. This is the earliest ``hook`` available. Note, that there is no mechanism provided for running only once. The boothook must take care of this itself. @@ -125,7 +125,7 @@ It is provided with the instance id in the environment variable ``INSTANCE_I``. Begins with: ``#cloud-boothook`` or ``Content-Type: text/cloud-boothook`` when using a MIME archive. Part Handler ------------- +============ This is a ``part-handler``. It will be written to a file in ``/var/lib/cloud/data`` based on its filename (which is generated). This must be python code that contains a ``list_types`` method and a ``handle_type`` method. @@ -147,7 +147,7 @@ The ``begin`` and ``end`` calls are to allow the part handler to do initializati Begins with: ``#part-handler`` or ``Content-Type: text/part-handler`` when using a MIME archive. Example -~~~~~~~ +------- .. literalinclude:: ../../examples/part-handler.txt :language: python @@ -157,3 +157,4 @@ Also this `blog`_ post offers another example for more advanced usage. .. [#] See your cloud provider for applicable user-data size limitations... .. _blog: http://foss-boss.blogspot.com/2011/01/advanced-cloud-init-custom-handlers.html +.. vi: textwidth=78 |