Add prefix to all outgoing request

[ElevnLi]

Hey there,

We are trying to integrate cvat into out open source Weed annotation platform.
We want to deploy cvat behind our nginx reverse proxy, and direct all the traffic of https://weed-ai.sydney.edu.au/annotation/ to traefik and then to cvat and cvat-ui. I'm using the traefik middleware to strip the prefix of the request like below:

  cvat:
    container_name: cvat
    image: openvino/cvat_server
    restart: always
    depends_on:
      - cvat_redis
      - cvat_db
    environment:
      DJANGO_MODWSGI_EXTRA_ARGS: ''
      ALLOWED_HOSTS: '*'
      CVAT_REDIS_HOST: 'cvat_redis'
      CVAT_POSTGRES_HOST: 'cvat_db'
      ADAPTIVE_AUTO_ANNOTATION: 'false'
    labels:
      - traefik.enable=true
      - traefik.http.services.cvat.loadbalancer.server.port=8080
      - traefik.http.routers.cvat.rule=Host(`${CVAT_HOST:-localhost}`) &&
          PathPrefix(`/annotation/api/`, `/annotation/git/`, `/annotation/opencv/`, `/annotation/analytics/`, `/annotation/static/`, `/annotation/admin`, `/annotation/documentation/`, `/annotation/django-rq`)
      - traefik.http.routers.cvat.entrypoints=web
      - traefik.http.routers.cvat.middlewares=add-cvat
      - traefik.http.middlewares.add-cvat.stripprefix.prefixes=/annotation
      - traefik.http.middlewares.add-cvat.stripprefix.forceSlash=true
    volumes:
      - cvat_data:/home/django/data
      - cvat_keys:/home/django/keys
      - cvat_logs:/home/django/logs
    networks:
      - cvat

Then when I request http://localhost/annotation/api/v1/tasks/2/data?type=preview, it's able to cut off the prefix.
My question is that is there a field you left for the frontend image or do you know a way to add prefix to every outgoing request, like when the frontend is communicating with the back, instead of requesting /api/..., it's requesting /annotation/api/..., then it's able to be redirected correctly.

Thanks for your help! We are really enjoying your work and happy to integrate it as a significant component of our platform.

Best,
Elevn

[nmanovic]

@ElevnLi , glad to hear that your team decided to integrate CVAT for data annotation. We don't have requested experience. Thus I will not be able to advise. At the same time we are ready to integrate necessary solutions which will help you with the task. Don't hesitate to send us a PR with required changes to support your platform.

One idea which I have in my mind is to modify root urls.py and add necessary prefix: https://github.com/openvinotoolkit/cvat/blob/c79a4c1584f6fd9781c974512a50ea0b64cdd431/cvat/urls.py. Basically you can do that even without source code modification (ask me how). At the same time you need to add the prefix into UI as well. I believe it isn't supported out of the box. Correct file to make necessary modifications in UI: https://github.com/openvinotoolkit/cvat/blob/develop/cvat-core/src/config.js
Also I see backendAPI variable here: https://github.com/openvinotoolkit/cvat/blob/961bc58935b065c245bfe5c822e98736b2278acb/cvat-ui/src/cvat-core-wrapper.ts

@bsekachev , any ideas?

P.S. Don't hesitate to mention yourself here after you integrate CVAT: https://github.com/openvinotoolkit/cvat/#partnershttps://github.com/openvinotoolkit/cvat/#partners

[bsekachev]

Basically you can set cvat.config.backendAPI to /<prefix>/api/v1/...
Maybe some additional changes are necessary, need to investigate.

[ElevnLi]

Thanks @nmanovic and @bsekachev. I found changing cvat.config.backendAPI very helpful to configure outgoing traffic for requesting backend api. I didn't modify anything for the backend, but simply add a middleware for traefik to strip prefix from the request. Also, I changed a lot of things regarding routes here and all links, buttons and history.push from events. These results in a success that all urls for cvat now have a prefix, like localhost/annotation/tasks.

Then when I integrate this infrastructure behind our nginx reverse proxy, it's always giving me '404 not found'. However, it finally works when I use traefik as the outer layer of proxy and actually put nginx behind it.

I'm trying to add a prefix variable in cvat to make all of these more generic to work with.

Thanks again for your quick reply and suggestions. Cheers.

[nmanovic]

@ElevnLi , thanks for the feedback. Don't hesitate to send us a PR with necessary fixes to simplify the integration process. We are ready to discuss, review and merge.