Pretty up the debug module

Previously the usage of the yaml_dumps module was causing
any python unicode key and value to show up as:

'item': !!python/unicode "some string"

This was not very pretty...

Fix this by using safe_dumps (which is also a good thing to
use and allow_unicode=True). Also create a tiny helper function
in the cc_debug module that does not include the yaml start and
end footers (since this module has its own footers and headers).

Also includes a basic sanity test for this module.

2 files changed, 21 insertions, 13 deletions

diff --git a/cloudinit/config/cc_debug.py b/cloudinit/config/cc_debug.py
index a3af4500..8c489426 100644
--- a/cloudinit/config/cc_debug.py
+++ b/cloudinit/config/cc_debug.py
@@ -33,11 +33,14 @@ It can be configured with the following option structure::
     Log configurations are not output.
 """
 
-from cloudinit import type_utils
-from cloudinit import util
 import copy
 from StringIO import StringIO
 
+from cloudinit import type_utils
+from cloudinit import util
+
+SKIP_KEYS = frozenset(['log_cfgs'])
+
 
 def _make_header(text):
     header = StringIO()
@@ -50,6 +53,11 @@ def _make_header(text):
     return header.getvalue()
 
 
+def _dumps(obj):
+    text = util.yaml_dumps(obj, explicit_start=False, explicit_end=False)
+    return text.rstrip()
+
+
 def handle(name, cfg, cloud, log, args):
     """Handler method activated by cloud-init."""
 
@@ -67,7 +75,7 @@ def handle(name, cfg, cloud, log, args):
         return
     # Clean out some keys that we just don't care about showing...
     dump_cfg = copy.deepcopy(cfg)
-    for k in ['log_cfgs']:
+    for k in SKIP_KEYS:
         dump_cfg.pop(k, None)
     all_keys = list(dump_cfg.keys())
     for k in all_keys:
@@ -76,10 +84,10 @@ def handle(name, cfg, cloud, log, args):
     # Now dump it...
     to_print = StringIO()
     to_print.write(_make_header("Config"))
-    to_print.write(util.yaml_dumps(dump_cfg))
+    to_print.write(_dumps(dump_cfg))
     to_print.write("\n")
     to_print.write(_make_header("MetaData"))
-    to_print.write(util.yaml_dumps(cloud.datasource.metadata))
+    to_print.write(_dumps(cloud.datasource.metadata))
     to_print.write("\n")
     to_print.write(_make_header("Misc"))
     to_print.write("Datasource: %s\n" %
diff --git a/cloudinit/util.py b/cloudinit/util.py
index b71057fb..ee5e5c0a 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -1274,14 +1274,14 @@ def read_write_cmdline_url(target_fn):
             logexc(LOG, "Failed writing url content to %s", target_fn)
 
 
-def yaml_dumps(obj):
-    formatted = yaml.dump(obj,
-                    line_break="\n",
-                    indent=4,
-                    explicit_start=True,
-                    explicit_end=True,
-                    default_flow_style=False)
-    return formatted
+def yaml_dumps(obj, explicit_start=True, explicit_end=True):
+    return yaml.safe_dump(obj,
+                          line_break="\n",
+                          indent=4,
+                          explicit_start=explicit_start,
+                          explicit_end=explicit_end,
+                          default_flow_style=False,
+                          allow_unicode=True)
 
 
 def ensure_dir(path, mode=None):