Using `FLAGSMITH_API_PROXY_URL` prevents the FE from reading the API `/version` endpoint

[matthewelwell]

How are you running Flagsmith

• Self Hosted with Docker
• Self Hosted with Kubernetes
• SaaS at flagsmith.com
• Some other way (add details in description below)

Describe the bug

When using the FE to proxy traffic to the API via the FLAGSMITH_API_PROXY_URL environment variable, the FE is unable to access the /version endpoint on the API because it only proxies traffic where the URI starts with /api/v1.

Note that this prevents the FE from determining if the running API is the enterprise version or not since the FE just responds with it's own /version endpoint and doesn't proxy to the API.

Steps To Reproduce

The following is a minimal docker-compose to reproduce the issue. Note that this is also the default behaviour in k8s.

volumes:
  pgdata:

services:
  postgres:
    image: postgres:15.5-alpine
    environment:
      POSTGRES_PASSWORD: password
      POSTGRES_DB: flagsmith
    container_name: flagsmith_postgres
    volumes:
      - pgdata:/var/lib/postgresql/data
    healthcheck:
      test: ['CMD-SHELL', 'pg_isready -d flagsmith -U postgres']
      interval: 2s
      timeout: 2s
      retries: 20
      start_period: 20s

  flagsmith-frontend:
    image: flagsmith/flagsmith-frontend:latest
    environment:
      FLAGSMITH_PROXY_API_URL: http://flagsmith-api:8000
    ports:
      - 8080:8080

  flagsmith-api:
    image: docker.flagsmith.com/flagsmith/flagsmith-api:latest
    environment:
      DATABASE_URL: postgresql://postgres:password@postgres:5432/flagsmith
      DJANGO_ALLOWED_HOSTS: '*'
      DJANGO_SECRET_KEY: secret
      TASK_RUN_METHOD: TASK_PROCESSOR
    depends_on:
      postgres:
        condition: service_healthy

  flagsmith-task-processor:
    image: docker.flagsmith.com/flagsmith/flagsmith:latest
    environment:
      DATABASE_URL: postgresql://postgres:password@postgres:5432/flagsmith
      DJANGO_ALLOWED_HOSTS: '*'
    ports:
      - 8001:8000
    depends_on:
      - flagsmith-api
    command: run-task-processor

Expected behavior

The FE can access the /version endpoint of the API.

Screenshots

No response