Make use of oslo-config-generator

oslo_config provide a utility for generating sample config files,
which provide more detail about opts, like Minimum/Maximum value
and Allowed values.

After this patch, new config options of masakari code should register
with masakari/conf/opts.py.

Change-Id: I8f2f7e87268498ebee7ca164db1c98ef43c279b0

etc/masakari/README-masakari.conf.txt

@@ -0,0 +1,4 @@
+To generate the sample masakari.conf file, run the following command from the top
+level of the masakari directory:
+
+    tox -egenconfig

etc/masakari/masakari-config-generator.conf

@@ -0,0 +1,10 @@
+[DEFAULT]
+output_file = etc/masakari/masakari.conf.sample
+wrap_width = 80
+namespace = masakari.conf
+namespace = masakari.api
+namespace = oslo.log
+namespace = oslo.policy
+namespace = oslo.db
+namespace = oslo.middleware
+namespace = keystonemiddleware.auth_token

releasenotes/notes/adopt-oslo-config-generator-cf2fdb17cf7f13db.yaml

@@ -0,0 +1,7 @@
+---
+other:
+    Adopt oslo-config-generator to generate sample config files.
+    New config options from masakari code should register with
+    masakari/conf/opts.py. A deprecated option should add a
+    deprecated group even if it didn't alter its group, otherwise
+    the deprecated group will use 'DEFAULT' by default.

setup.cfg

@@ -24,6 +24,12 @@ packages =
     masakari
 
 [entry_points]
+oslo.config.opts =
+    masakari.conf = masakari.conf.opts:list_opts
+
+oslo.config.opts.defaults =
+    masakari.api = masakari.common.config:set_middleware_defaults
+
 console_scripts =
     masakari-api = masakari.cmd.api:main
     masakari-manage = masakari.cmd.manage:main

tox.ini

@@ -16,6 +16,9 @@ commands = python setup.py test --slowest --testr-args='{posargs}'
 [testenv:common-constraints]
 install_command = pip install -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
 
+[testenv:genconfig]
+commands = oslo-config-generator --config-file=etc/masakari/masakari-config-generator.conf
+
 [testenv:pep8]
 commands = flake8 {posargs}
 deps = hacking