Refactor DeviceCertView

[a-martynovich]

Subtask of #216

DeviceCertView should be split in two, one for IS_API, another for IS_DASH (see branching by if 'format' in request.GET:). One branch of this code is currently used by agent, another branch is used by Dash. Instead, the part which is used by Dash should be part of Dash.

It will also allow us to remove hardcoded urls in models.Device.get_cert_url().

[rptrchv]

On me

[rptrchv]

@a-martynovich

One branch of this code is currently used by agent

I haven't managed to find any signs of this view usage by agent other than:
docs/examples/google-core-iot/README.md:$ curl -s "https://api.wott.io/v0.2/device-cert/$DEVICE_ID" > device.crt
which is quite the same like we use it in the Dash.
Moving this view's url pattern to the 'IS_DASH' section of urls.py seems quite reasonable and I'll do that after your confirmation it's enough for this task.

[a-martynovich]

@rptrchv The certificate retrieval via api.wott.io is needed for #278 and is used in WoTTsecurity/google-core-iot#1. It should probably require token authentication (the same as for listing all devices), but I'm not sure (@vpetersson ?)

[vpetersson]

No, public certificates should not require auth, because they are needed for some device-to-device communication.

[rptrchv]

@rptrchv The certificate retrieval via api.wott.io is needed for #278 and is used in WoTTsecurity/google-core-iot#1. It should probably require token authentication (the same as for listing all devices), but I'm not sure (@vpetersson ?)

None of the consumers of this view (including the ones you mentioned above) uses its branch if 'format' in request.GET:.
So I'm concluding we just need to have the same view available by 2 urls:

• one in the 'IS_API' section of urls.py
• another in the 'IS_DASH' section of urls.py

Also we need to get rid of if 'format' in request.GET: branch of the view.
Am I right?
@a-martynovich ^

[a-martynovich]

@rptrchv

So I'm concluding we just need to have the same view available by 2 urls:
Also we need to get rid of if 'format' in request.GET: branch of the view.

exactly so.