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author | Joshua Powers <josh.powers@canonical.com> | 2019-09-04 13:43:11 +0000 |
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committer | Server Team CI Bot <josh.powers+server-team-bot@canonical.com> | 2019-09-04 13:43:11 +0000 |
commit | da826cd3e4d608d8ddb4b693d10378b52532677b (patch) | |
tree | b884710f60c006a2c8be1838c38286bdf9109815 /doc/rtd/topics/format.rst | |
parent | ff11c0c63bfca0be451c58539b158acb7cb65a76 (diff) | |
download | vyos-cloud-init-da826cd3e4d608d8ddb4b693d10378b52532677b.tar.gz vyos-cloud-init-da826cd3e4d608d8ddb4b693d10378b52532677b.zip |
docs: fix whitespace, spelling, and line length
Diffstat (limited to 'doc/rtd/topics/format.rst')
-rw-r--r-- | doc/rtd/topics/format.rst | 81 |
1 files changed, 53 insertions, 28 deletions
diff --git a/doc/rtd/topics/format.rst b/doc/rtd/topics/format.rst index 74d1fee9..76050402 100644 --- a/doc/rtd/topics/format.rst +++ b/doc/rtd/topics/format.rst @@ -4,22 +4,24 @@ User-Data Formats ***************** -User data that will be acted upon by cloud-init must be in one of the following types. +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. +The uncompressed data will then be used as if it were not compressed. This is typically 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. +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. -For example, both a user data script and a cloud-config type could be specified. +For example, both a user data script and a cloud-config type could be +specified. Supported content-types: @@ -66,7 +68,8 @@ 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. +Begins with: ``#!`` or ``Content-Type: text/x-shellscript`` when using a MIME +archive. .. note:: New in cloud-init v. 18.4: User-data scripts can also render cloud instance @@ -83,25 +86,27 @@ Example #!/bin/sh echo "Hello World. The time is now $(date -R)!" | tee /root/output.txt - $ euca-run-instances --key mykey --user-data-file myscript.sh ami-a07d95c9 + $ euca-run-instances --key mykey --user-data-file myscript.sh ami-a07d95c9 Include File ============ This content is a ``include`` file. -The file contains a list of urls, one per line. -Each of the URLs will be read, and their content will be passed through this same set of rules. -Ie, the content read from the URL can be gzipped, mime-multi-part, or plain text. -If an error occurs reading a file the remaining files will not be read. +The file contains a list of urls, one per line. Each of the URLs will be read, +and their content will be passed through this same set of rules. Ie, the +content read from the URL can be gzipped, mime-multi-part, or plain text. If +an error occurs reading a file the remaining files will not be read. -Begins with: ``#include`` or ``Content-Type: text/x-include-url`` when using a MIME archive. +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. +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. These things include: @@ -114,9 +119,11 @@ These things include: .. note:: This file must be valid yaml syntax. -See the :ref:`yaml_examples` section for a commented set of examples of supported cloud config formats. +See the :ref:`yaml_examples` section for a commented set of examples of +supported cloud config formats. -Begins with: ``#cloud-config`` or ``Content-Type: text/cloud-config`` when using a MIME archive. +Begins with: ``#cloud-config`` or ``Content-Type: text/cloud-config`` when +using a MIME archive. .. note:: New in cloud-init v. 18.4: Cloud config dta can also render cloud instance @@ -126,25 +133,41 @@ Begins with: ``#cloud-config`` or ``Content-Type: text/cloud-config`` when using Upstart Job =========== -Content is placed into a file in ``/etc/init``, and will be consumed by upstart as any other 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. +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. -It is provided with the instance id in the environment variable ``INSTANCE_ID``. This could be made use of to provide a 'once-per-instance' type of functionality. +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. -Begins with: ``#cloud-boothook`` or ``Content-Type: text/cloud-boothook`` when using a MIME archive. +It is provided with the instance id in the environment variable +``INSTANCE_ID``. This could be made use of to provide a 'once-per-instance' +type of functionality. + +Begins with: ``#cloud-boothook`` or ``Content-Type: text/cloud-boothook`` when +using a MIME archive. Part Handler ============ -This is a ``part-handler``: It contains custom code for either supporting new mime-types in multi-part user data, or overriding the existing handlers for supported mime-types. 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`` function and a ``handle_part`` function. -Once the section is read the ``list_types`` method will be called. It must return a list of mime-types that this part-handler handles. Because mime parts are processed in order, a ``part-handler`` part must precede any parts with mime-types it is expected to handle in the same user data. +This is a ``part-handler``: It contains custom code for either supporting new +mime-types in multi-part user data, or overriding the existing handlers for +supported mime-types. 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`` function and a +``handle_part`` function. Once the section is read the ``list_types`` method +will be called. It must return a list of mime-types that this part-handler +handles. Because mime parts are processed in order, a ``part-handler`` part +must precede any parts with mime-types it is expected to handle in the same +user data. The ``handle_part`` function must be defined like: @@ -156,11 +179,13 @@ The ``handle_part`` function must be defined like: # filename = the filename of the part (or a generated filename if none is present in mime data) # payload = the parts' content -Cloud-init will then call the ``handle_part`` function once before it handles any parts, once per part received, and once after all parts have been handled. -The ``'__begin__'`` and ``'__end__'`` sentinels allow the part handler to do initialization or teardown before or after -receiving any parts. +Cloud-init will then call the ``handle_part`` function once before it handles +any parts, once per part received, and once after all parts have been handled. +The ``'__begin__'`` and ``'__end__'`` sentinels allow the part handler to do +initialization or teardown before or after receiving any parts. -Begins with: ``#part-handler`` or ``Content-Type: text/part-handler`` when using a MIME archive. +Begins with: ``#part-handler`` or ``Content-Type: text/part-handler`` when +using a MIME archive. Example ------- |