The devstack vars Q_PLUGIN_EXTRA_CONF_PATH and Q_PLUGIN_EXTRA_CONF_FILES are meant to be used in local.conf and other settings files in order to make sure the --config-file parameters get filled out and sent properly to neutron-server start.
The Q_PLUGIN_EXTRA_CONF_FILES parameter, in particular is a bash array and can be added to in order to set up multiple files. The Q_PLUGIN_EXTRA_CONF_PATH parameter will be prepended to each of the files specified in Q_PLUGIN_EXTRA_CONF_FILES, and is almost always set to '/etc/neutron'
The settings file in networking-l2gw's devstack plugin sets the Q_PLUGIN_EXTRA_CONF_FILES parameter, which, given the flow of devstack's stack command, will actually overwrite anything the user had set in local.conf, as well as any other plugins which have set up this variable prior to networking-l2gw's settings code getting run. This has the effect of sending only the l2gw_plugin.ini to --config-file upon neutron-server start, and will cause failures if other config files were needed by the devstack user.
Instead, this value should be appended to, to preserve any user settings. Also, setting the Q_PLUGIN_EXTRA_CONF_PATH also has the unfortunate side-effect of overwriting any user preference, or anything set by other plugins. Therefore, it might actually be preferable to not set it at all, and leave it to the user to set it in the local.conf.
Fix proposed to branch: master
Review: https:/