From 0fe96a44cde48cc688afe75beb8fd126c8892b8c Mon Sep 17 00:00:00 2001 From: Chad Smith Date: Thu, 2 Dec 2021 21:25:43 -0700 Subject: jinja: provide and document jinja-safe key aliases in instance-data (SC-622) (#1123) Allow #cloud-config and cloud-init query to use underscore-delimited "jinja-safe" key aliases for any instance-data.json keys containing jinja operator characters. This provides a means to use Jinja's dot-notation instead of square brackets and quoting to reference "unsafe" obtain attribute names. Support for these aliased keys is available to both #cloud-config user-data and `cloud-init query`. For example #cloud-config alias access can look like: {{ ds.config.user_network_config }} - instead of - {{ ds.config["user.network-config"] }} --- doc/rtd/topics/instancedata.rst | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'doc') diff --git a/doc/rtd/topics/instancedata.rst b/doc/rtd/topics/instancedata.rst index 6c17139f..c33b907a 100644 --- a/doc/rtd/topics/instancedata.rst +++ b/doc/rtd/topics/instancedata.rst @@ -530,12 +530,18 @@ Both user-data scripts and **#cloud-config** data support jinja template rendering. When the first line of the provided user-data begins with, **## template: jinja** cloud-init will use jinja to render that file. -Any instance-data-sensitive.json variables are surfaced as dot-delimited -jinja template variables because cloud-config modules are run as 'root' -user. +Any instance-data-sensitive.json variables are surfaced as jinja template +variables because cloud-config modules are run as 'root' user. - -Below are some examples of providing these types of user-data: +.. note:: + cloud-init also provides jinja-safe key aliases for any instance-data.json + keys which contain jinja operator characters such as +, -, ., /, etc. Any + jinja operator will be replaced with underscores in the jinja-safe key + alias. This allows for cloud-init templates to use aliased variable + references which allow for jinja's dot-notation reference such as + ``{{ ds.v1_0.my_safe_key }}`` instead of ``{{ ds["v1.0"]["my/safe-key"] }}``. + +Below are some other examples of using jinja templates in user-data: * Cloud config calling home with the ec2 public hostname and availability-zone -- cgit v1.2.3