cc_chef: fix bug when validation_key was present, but validation_cert was not

This fixes a bug in chef handling if the config contained the 'validation_key'
key, but not the 'validation_cert' key.

LP: #960547

2 files changed, 8 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index 0cf93c2a..27b412c8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -38,6 +38,9 @@
    (LP: #948461) [Ben Howard]
  - warn on non-multipart, non-handled user-data [Martin Packman]
  - run resizefs in the background in order to not block boot (LP: #961226)
+ - Fix bug in Chef support where validation_key was present in config, but
+   'validation_cert' was not (LP: #960547)
+
 0.6.2:
  - fix bug where update was not done unless update was explicitly set.
    It would not be run if 'upgrade' or packages were set to be installed
diff --git a/cloudinit/CloudConfig/cc_chef.py b/cloudinit/CloudConfig/cc_chef.py
index 090aaa37..941e04fe 100644
--- a/cloudinit/CloudConfig/cc_chef.py
+++ b/cloudinit/CloudConfig/cc_chef.py
@@ -40,11 +40,11 @@ def handle(_name, cfg, cloud, log, _args):
     # set the validation key based on the presence of either 'validation_key'
     # or 'validation_cert'. In the case where both exist, 'validation_key'
     # takes precedence
-    if ('validation_key' in chef_cfg or 'validation_cert' in chef_cfg):
-        validation_key = util.get_cfg_option_str(chef_cfg, 'validation_key',
-                                                 chef_cfg['validation_cert'])
-        with open('/etc/chef/validation.pem', 'w') as validation_key_fh:
-            validation_key_fh.write(validation_key)
+    for key in ('validation_key', 'validation_cert'):
+        if key in chef_cfg and chef_cfg[key]:
+            with open('/etc/chef/validation.pem', 'w') as validation_key_fh:
+                validation_key_fh.write(chef_cfg[key])
+            break
 
     # create the chef config from template
     util.render_to_file('chef_client.rb', '/etc/chef/client.rb',