use oslo.i18n to translate message in kolla

Now days, The Openstack i18n team has a limited capacity to translate message, so we want to make their work as effective as possible by identifying the most useful text
for them to translate.
See more details: http://docs.openstack.org/developer/oslo.i18n/guidelines.html

As we all known, there are many openstack service have achieved to translate message using oslo.i18n, including nova, neutron, cinder and so on. I think kolla is a important project which is used to deploy openstack. So kolla may achieved to translate message by using oslo.i18n module too.

Here is my plan.
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Step 1: To statistic all translate message.

In kolla project, we find some message in LOG.xxx() function and output help message for kolla commands should be use oslo.i18n.
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Step2: To statistic all directory file.

I have found all translate message are in kolla directory or docker directory
or in tests directory or in dev directory.
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Step3: To ensure which directory need to modify.

Actually, there is no doubt that tests/dev directory needn't to translate messages.
Because there are faced in developers. But what about kolla/docker directory?

Well, when I discussed this question in IRC, there is a argument about docker directory. So I'm sure kolla directory will need to use oslo.i18n.
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Step4: To know how to modify.
The oslo.i18n team give a official documents about how to use i18n.And here I give
links:
    http://docs.openstack.org/developer/oslo.i18n/usage.html

So here is conclusion about which directory to modify :
           ~kolla directory (needed)
           ~docker directory (discussing)
           ~dev directory (no need)
           ~tests directory (no need)