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, 3 insertions, 6 deletions

diff --git a/cloudinit/handlers/shell_script.py b/cloudinit/handlers/shell_script.py
index e4945a23..214714bc 100644
--- a/cloudinit/handlers/shell_script.py
+++ b/cloudinit/handlers/shell_script.py
@@ -17,21 +17,18 @@ from cloudinit import util
 from cloudinit.settings import (PER_ALWAYS)
 
 LOG = logging.getLogger(__name__)
-SHELL_PREFIX = "#!"
 
 
 class ShellScriptPartHandler(handlers.Handler):
+
+    prefixes = ['#!']
+
     def __init__(self, paths, **_kwargs):
         handlers.Handler.__init__(self, PER_ALWAYS)
         self.script_dir = paths.get_ipath_cur('scripts')
         if 'script_path' in _kwargs:
             self.script_dir = paths.get_ipath_cur(_kwargs['script_path'])
 
-    def list_types(self):
-        return [
-            handlers.type_from_starts_with(SHELL_PREFIX),
-        ]
-
     def handle_part(self, data, ctype, filename, payload, frequency):
         if ctype in handlers.CONTENT_SIGNALS:
             # TODO(harlowja): maybe delete existing things here