cli: add cloud-init query subcommand to query instance metadata

Cloud-init caches any cloud metadata crawled during boot in the file
/run/cloud-init/instance-data.json. Cloud-init also standardizes some of
that metadata across all clouds. The command 'cloud-init query' surfaces a
simple CLI to query or format any cached instance metadata so that scripts
or end-users do not have to write tools to crawl metadata themselves.

Since 'cloud-init query' is runnable by non-root users, redact any
sensitive data from instance-data.json and provide a root-readable
unredacted instance-data-sensitive.json. Datasources can now define a
sensitive_metadata_keys tuple which will redact any matching keys
which could contain passwords or credentials from instance-data.json.

Also add the following standardized 'v1' instance-data.json keys:
  - user_data: The base64encoded user-data provided at instance launch
  - vendor_data: Any vendor_data provided to the instance at launch
  - underscore_delimited versions of existing hyphenated keys:
    instance_id, local_hostname, availability_zone, cloud_name

1 files changed, 10 insertions, 0 deletions

diff --git a/cloudinit/cmd/main.py b/cloudinit/cmd/main.py
index 0eee583c..5a437020 100644
--- a/cloudinit/cmd/main.py
+++ b/cloudinit/cmd/main.py
@@ -791,6 +791,10 @@ def main(sysv_args=None):
                                      ' pass to this module'))
     parser_single.set_defaults(action=('single', main_single))
 
+    parser_query = subparsers.add_parser(
+        'query',
+        help='Query standardized instance metadata from the command line.')
+
     parser_dhclient = subparsers.add_parser('dhclient-hook',
                                             help=('run the dhclient hook'
                                                   'to record network info'))
@@ -842,6 +846,12 @@ def main(sysv_args=None):
             clean_parser(parser_clean)
             parser_clean.set_defaults(
                 action=('clean', handle_clean_args))
+        elif sysv_args[0] == 'query':
+            from cloudinit.cmd.query import (
+                get_parser as query_parser, handle_args as handle_query_args)
+            query_parser(parser_query)
+            parser_query.set_defaults(
+                action=('render', handle_query_args))
         elif sysv_args[0] == 'status':
             from cloudinit.cmd.status import (
                 get_parser as status_parser, handle_status_args)