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| author | Chad Smith <chad.smith@canonical.com> | 2018-09-11 17:31:46 +0000 |
|---|---|---|
| committer | Server Team CI Bot <josh.powers+server-team-bot@canonical.com> | 2018-09-11 17:31:46 +0000 |
| commit | c7555762f3a30190ce7726b4d013bc3e83c7e4b6 (patch) | |
| tree | 9f35cd8af4c33dc36ff5ee53574d20854273a309 /doc/rtd/topics/format.rst | |
| parent | 757247f9ff2df57e792e29d8656ac415364e914d (diff) | |
| download | vyos-cloud-init-c7555762f3a30190ce7726b4d013bc3e83c7e4b6.tar.gz vyos-cloud-init-c7555762f3a30190ce7726b4d013bc3e83c7e4b6.zip | |
user-data: jinja template to render instance-data.json in cloud-config
Allow users to provide '## template: jinja' as the first line or their
#cloud-config or custom script user-data parts. When this header exists,
the cloud-config or script will be rendered as a jinja template.
All instance metadata keys and values present in
/run/cloud-init/instance-data.json will be available as jinja variables
for the template. This means any cloud-config module or script can
reference any standardized instance data in templates and scripts.
Additionally, any standardized instance-data.json keys scoped below a
'<v#>' key will be promoted as a top-level key for ease of reference in
templates. This means that '{{ local_hostname }}' is the same as using the
latest '{{ v#.local_hostname }}'.
Since instance-data is written to /run/cloud-init/instance-data.json, make
sure it is persisted across reboots when the cached datasource opject is
reloaded.
LP: #1791781
Diffstat (limited to 'doc/rtd/topics/format.rst')
| -rw-r--r-- | doc/rtd/topics/format.rst | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/doc/rtd/topics/format.rst b/doc/rtd/topics/format.rst index 1b0ff366..15234d21 100644 --- a/doc/rtd/topics/format.rst +++ b/doc/rtd/topics/format.rst @@ -1,6 +1,8 @@ -******* -Formats -******* +.. _user_data_formats: + +***************** +User-Data Formats +***************** User data that will be acted upon by cloud-init must be in one of the following types. @@ -65,6 +67,11 @@ 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. +.. note:: + New in cloud-init v. 18.4: User-data scripts can also render cloud instance + metadata variables using jinja templating. See + :ref:`instance_metadata` for more information. + Example ------- @@ -103,12 +110,18 @@ These things include: - certain ssh keys should be imported - *and many more...* -**Note:** The file must be valid yaml syntax. +.. 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. 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 + metadata variables using jinja templating. See + :ref:`instance_metadata` for more information. + Upstart Job =========== |