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

1 files changed, 2 insertions, 0 deletions

diff --git a/bash_completion/cloud-init b/bash_completion/cloud-init
index f38164b0..b3a5ced3 100644
--- a/bash_completion/cloud-init
+++ b/bash_completion/cloud-init
@@ -62,6 +62,8 @@ _cloudinit_complete()
                 net-convert)
                     COMPREPLY=($(compgen -W "--help --network-data --kind --directory --output-kind" -- $cur_word))
                     ;;
+                render)
+                    COMPREPLY=($(compgen -W "--help --instance-data --debug" -- $cur_word))
                 schema)
                     COMPREPLY=($(compgen -W "--help --config-file --doc --annotate" -- $cur_word))
                     ;;