Add exclude-groups option to config validator

When dynamic groups are used, the sample config data may not know
about those group names. As a result, validation of such files will
always fail. This makes it hard to automate config checks since the
output would need to be inspected manually to verify that the missing
options are all from the dynamic group.

Ideally, we would provide some way to map sample config groups to
the dynamic group name used in the actual config, but that would be
more complicated and still might not work in every case if a project
doesn't include sample sections for a dynamic group (although they
_should_ be doing so).

Allowing certain group names to be excluded from validation lets
us to solve this problem in a simple way and maintain validation of
99%[0] of the config options and enables the validation to be scripted
since it won't need manual verification of the error output.

Change-Id: I352fd48f86ecb876fe26a5e50e9a2633af1fff3d
0: citation needed ;-)

1 files changed, 8 insertions, 0 deletions

diff --git a/releasenotes/notes/validator-exclude-groups-ad2f046522a3407e.yaml b/releasenotes/notes/validator-exclude-groups-ad2f046522a3407e.yaml
new file mode 100644
index 0000000..64973e2
--- /dev/null
+++ b/releasenotes/notes/validator-exclude-groups-ad2f046522a3407e.yaml
@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    The ``oslo-config-validator`` tool now has a new option,
+    ``--exclude-group``, that allows deployers to ignore certain groups that
+    might not appear in the sample config data, perhaps because the name of
+    the group depends on other configuration values. This way the validator
+    can still be used on the known groups.