Add log translation hints for Heat

Current oslo libraries support translating log messages using different
translation domains and oslo would like to see hints in all of our code
by the end of juno. So Heat should handle the changes out over the
release.

blueprint log-translation-hints

Change-Id: If0fba45f970ef0618b0bf3fdc46eaa2dc7fac0d0

specs/log-translation-hints.rst

@@ -0,0 +1,121 @@
+..
+ This work is licensed under a Creative Commons Attribution 3.0 Unported
+ License.
+
+ http://creativecommons.org/licenses/by/3.0/legalcode
+
+..
+ This template should be in ReSTructured text. The filename in the git
+ repository should match the launchpad URL, for example a URL of
+ https://blueprints.launchpad.net/heat/+spec/awesome-thing should be named
+ awesome-thing.rst .  Please do not delete any of the sections in this
+ template.  If you have nothing to say for a whole section, just write: None
+ For help with syntax, see http://sphinx-doc.org/rest.html
+ To test out your formatting, see http://www.tele3.cz/jbar/rest/rest.html
+
+==================================
+Add log translation hints for Heat
+==================================
+
+https://blueprints.launchpad.net/Heat/+spec/log-translation-hints
+
+To update Heat log messages to take advantage of oslo's new feature of
+supporting translating log messages using different translation domains.
+
+Problem description
+===================
+
+Current oslo libraries support translating log messages using different
+translation domains and oslo would like to see hints in all of our code
+by the end of juno. So Heat should handle the changes out over the release.
+
+Proposed change
+===============
+
+Since there are too many files need to change, so divide this bp into dozens of
+patches according to Heat directories(which need applying this change).
+
+For each directory's files, we change all the log messages as follows.
+
+1. Change "LOG.error(_(" to "LOG.error(_LE".
+
+2. Change "LOG.warn(_(" to "LOG.warn(_LW(".
+
+3. Change "LOG.info(_(" to "LOG.info(_LI(".
+
+4. Change "LOG.critical(_(" to "LOG.critical(_LC(".
+
+Note that this spec and associated blueprint are not to address the problem of
+removing translation of debug messages.
+
+Alternatives
+------------
+
+None
+
+Implementation
+==============
+
+Assignee(s)
+-----------
+
+Primary assignee:
+  liusheng<liusheng@huawei.com>
+
+Milestones
+----------
+
+Target Milestone for completion:
+  Juno-3
+
+Work Items
+----------
+
+For each directory's files, we change all the log messages as follows.
+
+1. Change "LOG.error(_(" to "LOG.error(_LE".
+
+2. Change "LOG.warn(_(" to "LOG.warn(_LW(".
+
+3. Change "LOG.info(_(" to "LOG.info(_LI(".
+
+4. Change "LOG.critical(_(" to "LOG.critical(_LC(".
+
+We handle these changes in the following order::
+
+    ├── contrib           #TODO1
+    ├── heat
+    │   ├── api        #TODO2
+    │   ├── cloudinit  #TODO3
+    │   ├── cmd
+    │   ├── common     #TODO4
+    │   ├── db         #TODO5
+    │   ├── doc
+    │   ├── engine     #TODO6
+    │   ├── locale
+    │   ├── openstack  #TODO7
+    │   ├── rpc        #TODO8
+    │   ├── scaling    #TODO9
+    │   ├── tests      #TODO10
+
+Add a HACKING check rule to ensure that log messages to relative domain.
+Using regular expression to check whether log messages with relative _L*
+function.
+
+::
+
+    log_translation_domain_info =re.compile(
+        r"(.)*LOG\.info\(\s*_LI\(('|\")")
+    log_translation_domain_warning = re.compile(
+        r"(.)*LOG\.(warn|warning)\(\s*_LW\(('|\")")
+    log_translation_domain_error = re.compile(
+        r"(.)*LOG\.error\(\s*_LE\(('|\")")
+    log_translation_domain_critical = re.compile(
+        r"(.)*LOG\.critical\(\s*_LC\(('|\")")
+
+Dependencies
+============
+
+[1]https://blueprints.launchpad.net/oslo/+spec/log-messages-translation-domain-rollout
+
+[2]https://wiki.openstack.org/wiki/LoggingStandards