Datasources: Formalize DataSource get_data and related properties.

Each DataSource subclass must define its own get_data method. This branch
formalizes our DataSource class to require that subclasses define an
explicit dsname for sourcing cloud-config datasource configuration.
Subclasses must also override the _get_data method or a
NotImplementedError is raised.

The branch also writes /run/cloud-init/instance-data.json. This file
contains all meta-data, user-data and vendor-data and a standardized set
of metadata keys in a json blob which other utilities with root-access
could make use of. Because some meta-data or user-data is potentially
sensitive the file is only readable by root.

Generally most metadata content types should be json serializable. If
specific keys or values are not serializable, those specific values will
be base64encoded and the key path will be listed under the top-level key
'base64-encoded-keys' in instance-data.json. If json writing fails due to
other TypeErrors or UnicodeDecodeErrors, a warning log will be emitted to
/var/log/cloud-init.log and no instance-data.json will be created.

2 files changed, 4 insertions, 8 deletions

diff --git a/cloudinit/analyze/__main__.py b/cloudinit/analyze/__main__.py
index 69b9e43e..3ba5903f 100644
--- a/cloudinit/analyze/__main__.py
+++ b/cloudinit/analyze/__main__.py
@@ -6,6 +6,8 @@ import argparse
 import re
 import sys
 
+from cloudinit.util import json_dumps
+
 from . import dump
 from . import show
 
@@ -112,7 +114,7 @@ def analyze_show(name, args):
 def analyze_dump(name, args):
     """Dump cloud-init events in json format"""
     (infh, outfh) = configure_io(args)
-    outfh.write(dump.json_dumps(_get_events(infh)) + '\n')
+    outfh.write(json_dumps(_get_events(infh)) + '\n')
 
 
 def _get_events(infile):
diff --git a/cloudinit/analyze/dump.py b/cloudinit/analyze/dump.py
index ca4da496..b071aa19 100644
--- a/cloudinit/analyze/dump.py
+++ b/cloudinit/analyze/dump.py
@@ -2,7 +2,6 @@
 
 import calendar
 from datetime import datetime
-import json
 import sys
 
 from cloudinit import util
@@ -132,11 +131,6 @@ def parse_ci_logline(line):
     return event
 
 
-def json_dumps(data):
-    return json.dumps(data, indent=1, sort_keys=True,
-                      separators=(',', ': '))
-
-
 def dump_events(cisource=None, rawdata=None):
     events = []
     event = None
@@ -169,7 +163,7 @@ def main():
     else:
         cisource = sys.stdin
 
-    return json_dumps(dump_events(cisource))
+    return util.json_dumps(dump_events(cisource))
 
 
 if __name__ == "__main__":